Weight-based bullying linked to increased adolescent alcohol, marijuana use
Overweight girls most likely to report being bullied, study finds
February 25, 2020
Science Daily/American Psychological Association
Adolescents who are bullied about their weight or body shape may be more likely to use alcohol or marijuana than those who are not bullied, according to new research published by the American Psychological Association.
The link between appearance-related teasing and substance use was strongest among overweight girls, raising special concerns about this group.
"This type of bullying is incredibly common and has many negative effects for adolescents," said lead study author Melanie Klinck, BA, a clinical research assistant at the University of Connecticut. "The combination of appearance-related teasing and the increased sensitivity to body image during adolescence may create a heightened risk for substance use."
"These findings raise larger issues about how society places too much emphasis on beauty and body image for girls and women and the damaging effects that may result," said Christine McCauley Ohannessian, PhD, professor of pediatrics and psychiatry at the University of Connecticut School of Medicine, as well as director of the Center for Behavioral Health at Connecticut Children's Medical Center and a study co-author.
"Schools and communities should specifically address appearance-related teasing in anti-bullying policies and substance-use interventions," she said. "Parents particularly have a role to play in addressing this issue. There is some startling research showing that some of the most hurtful examples of weight-based teasing come from parents or siblings, so families should be kind when they discuss the weight of their children."
The study, which was conducted at Connecticut Children's Medical Center, involved a survey of 1,344 students ages 11 to 14 from five public middle schools near Hartford, Connecticut. The students were asked if siblings, parents or peers had teased them about their weight, body shape or eating during the prior six months. More than half (55%) of the overall participants reported weight-based teasing, including three out of four overweight girls (76%), 71% of overweight boys, 52% of girls who weren't overweight, and 43% of boys who weren't overweight.
The participants also were asked about their alcohol and marijuana use. The results showed that frequent weight-based teasing was associated with higher levels of total alcohol use, binge drinking and marijuana use. In a follow-up survey six months later, weight-based teasing was still linked to total alcohol use and binge drinking. The research was published online in Psychology of Addictive Behaviors.
Previous research has found that boys have greater substance use in their teens and early adulthood, but girls begin using alcohol and drugs at an earlier age compared with boys. Those trends may be related to the societal pressures for girls to adhere to unrealistic body image ideals. This can damage their sense of self-worth and contribute to eating disorders and self-medication through substance use to cope with teasing or fit in with their peers, Klinck said.
"The old saying that 'sticks and stones may break my bones but words will never hurt me' is a fallacy that ignores the serious effects of emotional abuse and verbal bullying," Klinck said. "Weight-based discrimination appears to be one of the most common and seemingly socially sanctioned reasons to bully or discriminate against someone. As a society, we need to address the damage caused by this, especially for girls."
https://www.sciencedaily.com/releases/2020/02/200225154338.htm
The effects of obesity mirror those of aging
Researchers identify a shared list of health issues, from DNA damage to cognitive decline
February 25, 2020
Science Daily/Concordia University
Researchers argue that obesity should be considered premature aging. They look at how obesity predisposes people to acquiring the kinds of potentially life-altering or life-threatening diseases normally seen in older individuals: compromised genomes, weakened immune systems, decreased cognition, increased chances of developing type 2 diabetes, Alzheimer's disease, cardiovascular disease, cancer and other illnesses.
Globally, an estimated 1.9 billion adults and 380 million children are overweight or obese. According to the World Health Organization, more people are dying from being overweight than underweight. Researchers at Concordia are urging health authorities to rethink their approach to obesity.
In their paper published in the journal Obesity Reviews, the researchers argue that obesity should be considered premature aging. They look at how obesity predisposes people to acquiring the kinds of potentially life-altering or life-threatening diseases normally seen in older individuals: compromised genomes, weakened immune systems, decreased cognition, increased chances of developing type 2 diabetes, Alzheimer's disease, cardiovascular disease, cancer and other illnesses.
The study was led by Sylvia Santosa, associate professor of health, kinesiology and applied physiology in the Faculty of Arts and Science. She and her colleagues reviewed more than 200 papers that looked at obesity's effects, from the level of the cell to tissue to the entire body. The study was co-authored by Bjorn Tam, Horizon postdoctoral fellow, and José Morais, an associate professor in the Department of Medicine at McGill University.
"We are trying to comprehensively make the argument that obesity parallels aging," explains Santosa, a Tier II Canada Research Chair in Clinical Nutrition. "Indeed, the mechanisms by which the comorbidities of obesity and aging develop are very similar."
From cells to systems
The paper looks at ways obesity ages the body from several different perspectives. Many previous studies have already linked obesity to premature death. But the researchers note that at the lowest levels inside the human body, obesity is a factor that directly accelerates the mechanisms of aging.
For instance, Santosa and her colleagues look at the processes of cell death and the maintenance of healthy cells -- apoptosis and autophagy, respectively -- that are usually associated with aging.
Studies have shown that obesity-induced apoptosis has been seen in mice hearts, livers, kidneys, neurons, inner ears and retinas. Obesity also inhibits autophagy, which can lead to cancer, cardiovascular disease, type 2 diabetes and Alzheimer's.
At the genetic level, the researchers write that obesity influences a number of alterations associated with aging. These include the shortening of protective caps found on the ends of chromosomes, called telomeres. Telomeres in patients with obesity can be more than 25 per cent shorter than those seen in control patients, for instance.
Santosa and her colleagues further point out that obesity's effects on cognitive decline, mobility, hypertension and stress are all similar to those of aging.
Pulling out from the cellular level, the researchers say obesity plays a significant role in the body's fight against age-related diseases. Obesity, they write, speeds up the aging of the immune system by targeting different immune cells, and that later weight reduction will not always reverse the process.
The effects of obesity on the immune system, in turn, affect susceptibility to diseases like influenza, which often affects patients with obesity at a higher rate than normal-weight individuals. They are also at higher risk of sarcopenia, a disease usually associated with aging that features a progressive decline in muscle mass and strength.
Finally, the paper spells out how individuals with obesity are more susceptible to diseases closely associated with later-life onset, such as type 2 diabetes, Alzheimer's and various forms of cancer.
Similarities too big to ignore
Santosa says the inspiration for this study came to her when she realized how many children with obesity were developing adult-onset conditions of diseases, such as hypertension, high cholesterol and type 2 diabetes. She also realized that the comorbidities of obesity were similar to that of aging.
"I ask people to list as many comorbidities of obesity as they can," Santosa says. "Then I ask how many of those comorbidities are associated with aging. Most people will say, all of them. There is certainly something that is happening in obesity that is accelerating our aging process.'"
She thinks this research will help people better understand how obesity works and stimulate ideas on how to treat it.
"I'm hoping that these observations will focus our approach to understanding obesity a little more, and at the same time allow us to think of obesity in different ways. We're asking different types of questions than that which have traditionally been asked."
https://www.sciencedaily.com/releases/2020/02/200225122954.htm
Losing tongue fat improves sleep apnea
Tongue could be a new target for treating the common sleep disorder
January 10, 2020
Science Daily/University of Pennsylvania School of Medicine
Using magnetic resonance imaging (MRI) to measure the effect of weight loss on the upper airway in obese patients, researchers found that reducing tongue fat is a primary factor in lessening the severity of OSA.
Losing weight is an effective treatment for Obstructive Sleep Apnea (OSA), but why exactly this is the case has remained unclear. Now, researchers in the Perelman School of Medicine at the University of Pennsylvania have discovered that improvements in sleep apnea symptoms appear to be linked to the reduction of fat in one unexpected body part -- the tongue.
Using magnetic resonance imaging (MRI) to measure the effect of weight loss on the upper airway in obese patients, researchers found that reducing tongue fat is a primary factor in lessening the severity of OSA. The findings were published today in the American Journal of Respiratory and Critical Care Medicine.
"Most clinicians, and even experts in the sleep apnea world, have not typically focused on fat in the tongue for treating sleep apnea," said Richard Schwab, MD, chief of Sleep Medicine. "Now that we know tongue fat is a risk factor and that sleep apnea improves when tongue fat is reduced, we have established a unique therapeutic target that we've never had before."
Twenty-two million Americans suffer from sleep apnea, a serious health condition in which breathing repeatedly stops and starts, causing patients to wake up randomly throughout their sleep cycles. The condition, which is usually marked by loud snoring, can increase your risk for high blood pressure and stroke. While obesity is the primary risk factor for developing sleep apnea, there are other causes, such as having large tonsils or a recessed jaw. CPAP (continuous positive airway pressure) machines improves sleep apnea in about 75 percent of patients, studies suggest, but for the other 25 percent -- those who may have trouble tolerating the machine -- alternative treatment options, such as oral appliances or upper airway surgery, are more complicated.
A 2014 study led by Schwab compared obese patients with and without sleep apnea, and found that the participants with the condition had significantly larger tongues and a higher percentage of tongue fat when compared to those without sleep apnea. The researchers next step was to determine if reducing tongue fat would improve symptoms and to further examine cause and effect.
The new study included 67 participants with mild to severe obstructive sleep apnea who were obese -- those with a body mass index greater than 30.0. Through diet or weight loss surgery, the patients lost nearly 10 percent of their body weight, on average, over six months. Overall, the participants' sleep apnea scores improved by 31 percent after the weight loss intervention, as measured by a sleep study.
Before and after the weight loss intervention, the study participants underwent MRI scans to both their pharynx as well as their abdomens. Then, using a statistical analysis, the research team quantified changes between overall weight loss and reductions to the volumes of the upper airway structures to determine which structures led to the improvement in sleep apnea. The team found that a reduction in tongue fat volume was the primary link between weight loss and sleep apnea improvement.
The study also found that weight loss resulted in reduced pterygoid (a jaw muscle that controls chewing) and pharyngeal lateral wall (muscles on the sides of the airway) volumes. Both these changes also improved sleep apnea, but not to the same extent as the reduction in tongue fat.
The authors believe that tongue fat is a potential new therapeutic target for improving sleep apnea. They suggest that future studies could be designed to explore whether certain low-fat diets are better than others in reducing tongue fat and whether cold therapies -- like those used to reduce stomach fat -- might be applied to reducing tongue fat. However, Schwab notes, these types of interventions have not yet been tested.
Schwab's team is also examining new interventions and other risk factors for sleep apnea, including whether some patients who are not obese but who have "fatty" tongues could be predisposed to sleep apnea, but are less likely to be diagnosed.
In a recent related study, Schwab found that ethnicity may also play a role in sleep apnea severity. His research team compared the upper airway anatomy of Chinese and Icelandic patients with sleep apnea, and found that, compared to Icelandic patients of similar age, gender, and symptoms, Chinese patients had smaller airways and soft tissues, but bigger soft palate volume with more bone restrictions. This means that Asian patients may generally be more at risk for severe sleep apnea symptoms. The bottom line, according to Schwab, is that all patients who suffer from snoring or sleepiness should be screened for sleep apnea, whether or not they appear to fall into the typical "high-risk" obese categories.
"Primary care doctors, and perhaps even dentists, should be asking about snoring and sleepiness in all patients, even those who have a normal body mass index, as, based on our data, they may also be at risk for sleep apnea," Schwab said.
https://www.sciencedaily.com/releases/2020/01/200110101035.htm
Mediterranean diet ingredient may extend life
Olive oil in the diet may also help mitigate aging-related diseases
February 21, 2020
Science Daily/University of Minnesota Medical School
Researchers at the University of Minnesota Medical School discover a potential new way in which diet influences aging-related diseases.
Doug Mashek, PhD, a professor in the Departments of Medicine and Biochemistry, Molecular Biology and Biophysics, leads a team of researchers who discovered that olive oil in the Mediterranean diet may hold the key to improving lifespan and mitigating aging-related diseases. Over the last eight years, with the help of multiple grants from the National Institutes of Health, their research findings were recently published in Molecular Cell.
Early studies on the diet suggested red wine was a major contributor to the health benefits of the Mediterranean diet because it contains a compound called resveratrol, which activated a certain pathway in cells known to increase lifespan and prevent aging-related diseases. However, work in Mashek's lab suggests that it is the fat in olive oil, another component of the Mediterranean diet, that is actually activating this pathway.
According to Mashek, merely consuming olive oil is not enough to elicit all of the health benefits. His team's studies suggest that when coupled with fasting, limiting caloric intake and exercising, the effects of consuming olive oil will be most pronounced.
"We found that the way this fat works is it first has to get stored in microscopic things called lipid droplets, which is how our cells store fat. And then, when the fat is broken down during exercising or fasting, for example, is when the signaling and beneficial effects are realized," Mashek said.
The next steps for their research are to translate it to humans with the goal of discovering new drugs or to further tailor dietary regimens that improve health, both short-term and long-term.
"We want to understand the biology, and then translate it to humans, hopefully changing the paradigm of healthcare from someone going to eight different doctors to treat his or her eight different disorders," Mashek said. "These are all aging-related diseases, so let's treat aging."
https://www.sciencedaily.com/releases/2020/02/200221125120.htm
People who eat a big breakfast may burn twice as many calories
Study finds eating more at breakfast instead of dinner could prevent obesity
February 19, 2020
Science Daily/The Endocrine Society
Eating a big breakfast rather than a large dinner may prevent obesity and high blood sugar, according to new research published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.
Our body expends energy when we digest food for the absorption, digestion, transport and storage of nutrients. This process, known as diet-induced thermogenesis (DIT), is a measure of how well our metabolism is working, and can differ depending on mealtime.
"Our results show that a meal eaten for breakfast, regardless of the amount of calories it contains, creates twice as high diet-induced thermogenesis as the same meal consumed for dinner," said the study's corresponding author, Juliane Richter, M.Sc., Ph.D., of University of Lübeck in Germany. "This finding is significant for all people as it underlines the value of eating enough at breakfast."
The researchers conducted a three-day laboratory study of 16 men who consumed a low-calorie breakfast and high-calorie dinner, and vice versa in a second round. They found identical calorie consumption led to 2.5 times higher DIT in the morning than in the evening after high-calorie and low-calorie meals. The food-induced increase of blood sugar and insulin concentrations was diminished after breakfast compared with dinner. The results also show eating a low-calorie breakfast increased appetite, specifically for sweets.
"We recommend that patients with obesity as well as healthy people eat a large breakfast rather than a large dinner to reduce body weight and prevent metabolic diseases," Richter said.
https://www.sciencedaily.com/releases/2020/02/200219092539.htm
Western diet rich in fat and sugar linked to skin inflammation
February 18, 2020
Science Daily/University of California - Davis Health
A Western diet rich in fat and sugar may lead to inflammatory skin diseases such as psoriasis, a study by UC Davis Health researchers has found.
The study, published today in Journal of Investigative Dermatology, suggests that dietary components, rather than obesity itself, may lead to skin inflammation and the development of psoriasis. A common and chronic skin disease, psoriasis causes skin cells to form scales and red patches that are itchy and sometimes painful.
Diet and Skin Inflammation
Previous studies have shown that obesity is a risk factor for the development or worsening of psoriasis. The Western diet, characterized by a high dietary intake of saturated fats and sucrose and low intake of fiber, has been linked to the increased prevalence of obesity in the world.
"In our study, we found that short-term exposure to Western diet is able to induce psoriasis before significant body weight gain," said Sam T. Hwang, professor and chair of dermatology at UC Davis and senior author on the study.
For the UC Davis Health study, which used a mouse model, Hwang and his colleagues found that a diet containing both high fat and high sugar (mimicking the Western diet in human) was required to induce observable skin inflammation. In four weeks only, mice on Western diet had significantly increased ear swelling and visible dermatitis compared to mice fed a controlled diet and those on high fat diet alone.
"Eating an unhealthy diet does not affect your waistline alone, but your skin immunity too," said Zhenrui Shi, visiting assistant researcher in UC Davis Department of Dermatology and lead author on the study.
Bile Acids and Skin Inflammation
The study detailed the mechanisms by which inflammation happens following a Western diet. It identified bile acids as key signaling molecules in the regulation of skin immunity. Bile acids are produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. They play an important role in dietary lipid absorption and cholesterol balance in the blood.
The study found that cholestyramine, a drug used to lower cholesterol levels by binding to bile acids in the intestine, helped reduce the risk of skin inflammation. The finding suggests that bile acids mediate the development of psoriasis. The binding of cholestyramine to bile acids in the gut and its subsequent release through the stool allows for lowering of skin inflammation.
Further studies are needed to understand the mechanism behind diet-induced skin inflammation and the interaction between metabolism, microbes and immunity.
https://www.sciencedaily.com/releases/2020/02/200218161720.htm
Mediterranean diet for one year promotes gut bacteria linked to 'healthy aging'
It may help curb advance of frailty and cognitive decline, suggest researchers
February 17, 2020
Science Daily/BMJ
Eating a Mediterranean diet for a year boosts the types of gut bacteria linked to 'healthy' ageing, while reducing those associated with harmful inflammation in older people, indicates a five-country study, published online in the journal Gut.
As ageing is associated with deteriorating bodily functions and increasing inflammation, both of which herald the onset of frailty, this diet might act on gut bacteria in such a way as to help curb the advance of physical frailty and cognitive decline in older age, suggest the researchers.
Previous research suggests that a poor/restrictive diet, which is common among older people, particularly those in long term residential care, reduces the range and types of bacteria (microbiome) found in the gut and helps to speed up the onset of frailty.
The researchers therefore wanted to see if a Mediterranean diet might maintain the microbiome in older people's guts, and promote the retention or even proliferation of bacteria associated with 'healthy' ageing.
They analysed the gut microbiome of 612 people aged 65 to 79, before and after 12 months of either eating their usual diet (n = 289) or a Mediterranean diet (n = 323), rich in fruits, vegetables, nuts, legumes, olive oil and fish and low in red meat and saturated fats, and specially tailored to older people (NU-AGE diet).
The participants, who were either frail (n=28), on the verge of frailty (n=151), or not frail (n=433) at the beginning of the study, lived in five different countries: France, Italy, Netherlands, Poland, and the UK.
Sticking to the Mediterranean diet for 12 months was associated with beneficial changes to the gut microbiome.
It was associated with stemming the loss of bacterial diversity; an increase in the types of bacteria previously associated with several indicators of reduced frailty, such as walking speed and hand grip strength, and improved brain function, such as memory; and with reduced production of potentially harmful inflammatory chemicals.
More detailed analysis revealed that the microbiome changes were associated with an increase in bacteria known to produce beneficial short chain fatty acids and a decrease in bacteria involved in producing particular bile acids, overproduction of which are linked to a heightened risk of bowel cancer, insulin resistance, fatty liver and cell damage.
What's more, the bacteria that proliferated in response to the Mediterranean diet acted as 'keystone' species, meaning they were critical for a stable 'gut ecosystem,' pushing out those microbes associated with indicators of frailty.
The changes were largely driven by an increase in dietary fibre and associated vitamins and minerals -- specifically, C, B6, B9, copper, potassium, iron, manganese, and magnesium.
The findings were independent of the person's age or weight (body mass index), both of which influence the make-up of the microbiome.
And while there were some differences in the make-up of a person's gut microbiome, depending on country of origin to start with, the response to the Mediterranean diet after 12 months was similar and consistent, irrespective of nationality.
The study findings can't establish a causative role for the microbiome in health, added to which some of the implications are inferred rather than directly measured, say the researchers.
"The interplay of diet, microbiome and host health is a complex phenomenon influenced by several factors," they emphasise.
"While the results of this study shed light on some of the rules of this three-way interplay, several factors such as age, body mass index, disease status and initial dietary patterns may play a key role in determining the extent of success of these interactions," they explain.
Older people may have dental problems and/or difficulty swallowing, so it may be impractical for them to eat a Mediterranean diet, they add. But the beneficial bacteria implicated in healthy ageing found in this study might yet prove useful therapeutic agents to ward off frailty, they suggest.
https://www.sciencedaily.com/releases/2020/02/200217192025.htm
The skinny on why poor sleep may increase heart risk in women
February 17, 2020
Science Daily/Columbia University Irving Medical Center
Women who sleep poorly tend to overeat and consume a lower-quality diet, according to a new study from researchers at Columbia University Irving Medical Center. The findings provide new insight into how poor sleep quality can increase the risk of heart disease and obesity and points to possible interventions for improving women's heart health.
Previous studies have shown that people who get less sleep are more likely to develop obesity, type 2 diabetes, and heart disease -- and that the relationship may be partially explained by diet. But these studies were narrowly focused on specific foods or nutrients (such as fish, sweets, or saturated fat) or only measured sleep duration, not sleep quality.
The new study was designed to get a more comprehensive picture in women by examining associations between overall diet quality and multiple aspects of sleep quality.
"Women are particularly prone to sleep disturbances across the life span, because they often shoulder the responsibilities of caring for children and family and, later, because of menopausal hormones," says Brooke Aggarwal, EdD, assistant professor of medical sciences at Columbia University Vagelos College of Physicians and Surgeons and senior author of the study.
The study of nearly 500 women was published online today in the Journal of the American Heart Association.
The researchers analyzed the sleep and eating habits of an ethnically diverse group of 495 women, ages 20 to 76. The study looked at sleep quality, the time it took to fall asleep, and insomnia. The women also reported on the types and amounts of foods they typically eat throughout the year, allowing researchers to measure their typical dietary patterns.
Similar to previous studies of sleep and diet, the study found that those with worse overall sleep quality consumed more of the added sugars associated with obesity and diabetes.
Women who took longer to fall asleep had higher caloric intake and ate more food by weight.
And women with more severe insomnia symptoms consumed more food by weight and fewer unsaturated fats than women with milder insomnia.
"Our interpretation is that women with poor-quality sleep could be overeating during subsequent meals and making more unhealthy food choices," says Aggarwal.
The question remains: How might poor sleep contribute to poor eating?
"Poor sleep quality may lead to excessive food and calorie intake by stimulating hunger signals or suppressing signals of fullness," says Faris Zuraikat, PhD, postdoctoral fellow at Columbia University Vagelos College of Physicians and Surgeons and lead author of the study. "Fullness is largely affected by the weight or volume of food consumed, and it could be that women with insomnia consume a greater amount of food in an effort to feel full.
"However, it's also possible that poor diet has a negative impact on women's sleep quality," adds Zuraikat. "Eating more could also cause gastrointestinal discomfort, for instance, making it harder to fall asleep or remain asleep."
"Given that poor diet and overeating may lead to obesity -- a well-established risk factor for heart disease -- future studies should test whether therapies that improve sleep quality can promote cardiometabolic health in women," says Aggarwal.
About the Study
The women in the study were participants in the American Heart Association's Go Red for Women Strategically Focused Research Network at Columbia University Irving Medical Center.
Two other research teams in Columbia's Go Red for Women network are studying the impact of sleep restriction on risk factors for heart disease and on the cells that line blood vessels.
The study is titled "Measures of Poor Sleep Quality Are Associated with Higher Energy Intake and Poor Diet Quality in a Diverse Sample of Women from the Go Red for Women Strategically Focused Research Network."
https://www.sciencedaily.com/releases/2020/02/200217085214.htm
Fast food intake leads to weight gain in preschoolers
February 14, 2020
Science Daily/The Geisel School of Medicine at Dartmouth
There is a strong link between the amount of fast food that pre-school age children consume and their likelihood of becoming overweight or obese, according to a new Dartmouth-led study, published in the journal Pediatric Obesity.
According to the Centers for Disease Control and Prevention, nearly 25 percent of children between the ages of 2 and 5 years are overweight or obese in the U.S. These conditions increase the risk of numerous physical and psychosocial problems during childhood, including fatty liver disease, type 2 diabetes, and depression.
"We now know from our studies and others, that kids who start on the path of extra weight gain during this really important timeframe tend to carry it forward into adolescence and adulthood, and this sets them up for major health consequences as they get older," says first author Jennifer Emond, PhD, MS, an assistant professor of biomedical data science and of pediatrics at the Geisel School of Medicine at Dartmouth.
Previous research has shown that fast-food intake is common among children -- about one-third of U.S. children consume fast food daily -- and has suggested that there is an association between fast food consumption and children becoming overweight or obese. But it hasn't been clear whether eating fast food independently contributes to excess weight gain at such a young age.
In an effort to make this determination, the investigators followed a cohort of more than 500 pre-school age children (ages 3 to 5) and their families in southern New Hampshire for one year. The height and weight of the children were measured at the beginning and end of the study. Parents reported their children's fast-food intake frequency weekly -- from 11 chain fast-food restaurants -- in six online surveys that were completed at two-month intervals.
The researchers found that at the beginning of the study, about 18 percent of the children were overweight and nearly 10 percent were obese. Importantly, about 8 percent of children transitioned to a greater weight status over the one-year period.
"To our knowledge, ours is the first study to follow a cohort over time and to show that fast food, by itself, uniquely contributes to weight gain," explains Emond. "Unlike with past research, we were able to adjust for other factors -- such as exercise and screen time -- that could possibly explain away this relationship.
"Findings from this research," says Emond, "should be used to inform guidelines and policies that can reduce fast-food marketing exposure to children and help support parents who may be struggling to adopt healthier eating behaviors for their kids."
https://www.sciencedaily.com/releases/2020/02/200214134723.htm
Green tea extract combined with exercise reduces fatty liver disease in mice
Although untested in human trials, results suggest a potential health strategy
February 14, 2020
Science Daily/Penn State
The combination of green tea extract and exercise reduced the severity of obesity-related fatty liver disease by 75% in mice fed a high-fat diet, according to researchers, whose recent study may point to a potential health strategy for people.
The outcome is important, explained Joshua Lambert, associate professor of food science, because nonalcoholic fatty liver disease is a significant global health problem that is expected to worsen. Because of the high prevalence of risk factors such as obesity and type 2 diabetes, fatty liver disease is forecast to afflict more than 100 million people by 2030. And there are currently no validated therapies for the disease.
In the study, mice fed a high-fat diet for 16 weeks that consumed green tea extract and exercised regularly by running on a wheel were found to have just a quarter of the lipid deposits in their livers compared to those seen in the livers of a control group of mice. Mice that were treated with green tea extract alone or exercise alone had roughly half as much fat in their livers as the control group.
In addition to analyzing the liver tissues of mice in the study, which was published recently in the Journal of Nutritional Biochemistry, researchers also measured the protein and fat content in their feces. They found that the mice that consumed green tea extract and exercised had higher fecal lipid and protein levels.
"By examining the livers of these mice after the study concluded and by screening their feces during the research, we saw that the mice that consumed green tea extract and exercised actually were processing nutrients differently -- their bodies were handling food differently," Lambert said.
"We think the polyphenols in green tea interact with digestive enzymes secreted in the small intestine and partially inhibit the breakdown of carbohydrates, fat and protein in food," he added. "So, if a mouse doesn't digest the fat in its diet, that fat and the calories associated with it pass through the mouse's digestive system, and a certain amount of it ends up coming out in its feces."
It may be significant, Lambert explained, that mice treated with both green tea extract and exercise had higher expression of genes related to the formation of new mitochondria. That gene expression is important, he said, because it provides markers that will help researchers understand the mechanism by which green tea polyphenols and exercise might work together to mitigate fatty liver deposits.
"We measured the expression of genes that we know are related to energy metabolism and play an important role in energy utilization," Lambert said. "In the mice that had the combination treatment, we saw an increase in the expression of genes that wasn't there before they consumed green tea extract and exercised."
More research is needed to see if there is a synergy created by green tea extract and exercise working together to reduce fat deposited in the liver, or if the effects are simply additive, Lambert pointed out. His research group in the College of Agricultural Sciences for 12 years has studied the health benefits of polyphenols -- often called antioxidants -- from green tea, cocoa, avocados and other sources.
In previous related research, Lambert and colleagues demonstrated that green tea extract and exercise together sharply reduced body mass and improved cardiovascular health of high-fat-fed mice. But because no human trials assessing the health benefits and risks of green tea combined with exercise have been conducted, he urges caution for people who decide to experiment with the health strategy on their own.
"I believe people should engage in more physical activity, and replacing high-calorie beverages with decaffeinated, diet green tea -- which has no calories -- is a smart move," he said. "Combining the two might have health benefits for people, but we don't have the clinical data yet."
https://www.sciencedaily.com/releases/2020/02/200214134655.htm
Natural compound in vegetables helps fight fatty liver disease
New research shows how indole can reduce inflammation, fatty deposits
February 7, 2020
Science Daily/Texas A&M AgriLife Communications
A new study led by Texas A&M AgriLife Research scientists shows how a natural compound found in many well-known and widely consumed vegetables can also be used to fight fatty liver disease.
The study demonstrates how non-alcoholic fatty liver disease, or NAFLD, can be controlled by indole, a natural compound found in gut bacteria -- and in cruciferous vegetables such as cabbage, kale, cauliflower and Brussels sprouts. It also addresses how this natural compound may lead to new treatments or preventive measures for NAFLD.
The study was recently published in Hepatology.
"Based on this research, we believe healthy foods with high capacity for indole production are essential for preventing NAFLD and are beneficial for improving the health of those with it," said Chaodong Wu, M.D., Ph.D., a Texas A&M AgriLife Research Faculty Fellow and principal investigator for the study. "This is another example where altering the diet can help prevent or treat disease and improve the well-being of the individual."
About NAFLD and indole
NAFLD occurs when the liver becomes "marbled" with fat, sometimes due to unhealthy nutrition, such as excessive intake of saturated fats. If not properly addressed, this condition can lead to life-threatening liver disease, including cirrhosis or liver cancer.
Many diverse factors contribute to NAFLD. Fatty liver is seven to 10 times more common in people with obesity than in the general population. In addition, obesity causes inflammation in the body. Driving this inflammation are macrophages, types of white blood cells that normally battle infection. This inflammation exacerbates liver damage in those with liver disease.
Gut bacteria can also have an effect -- either positive or negative -- on the progression of fatty liver disease. These bacteria produce many different compounds, one of which is indole. This product of the amino acid tryptophan has been identified by clinical nutritionists and nutrition scientists as likely having preventive and therapeutic benefits to people with NAFLD.
The National Cancer Institute also notes the benefits of indole-3-carbinol found in cruciferous vegetables, including their anti-inflammatory and cancer-fighting properties.
A comprehensive and multi-level study on fatty liver disease
The present study examined the effect of indole concentrations on people, animal models and individual cells to help determine indole's effect on liver inflammation and its potential benefits to people with NAFLD. It investigated the extent to which indole alleviates non-alcoholic fatty liver disease, incorporating previous findings on gut bacteria, intestinal inflammation and liver inflammation. It also incorporated investigation into how indole improves fatty liver in animal models.
For the study, researchers investigated the effects of indole on individuals with fatty livers. As research collaborator Qifu Li, M.D., was also a physician at Chongqing Medical University in China, the team decided he should lead the clinical research using Chinese participants.
In 137 subjects, the research team discovered people with a higher body mass index tended to have lower levels of indole in their blood. Additionally, the indole levels in those who were clinically obese were significantly lower than those who were considered lean. And in those with lower indole levels, there was also a higher amount of fat deposition in the liver.
This result will likely extend to other ethnicities, Li noted, though ethnic background may have some influence on gut bacteria populations and the exact levels of metabolites.
To further determine the impact of indole, the research team used animal models fed a low-fat diet as a control and high-fat diet to simulate the effects of NAFLD.
"The comparisons of animal models fed a low-fat diet and high-fat diet gave us a better understanding of how indole is relevant to NAFLD," said Gianfranco Alpini, M.D., a study collaborator and former distinguished professor of Texas A&M Health Science Center, now the director of the Indiana Center for Liver Research.
Alpini said treatment of NAFLD-mimicking animal models with indole significantly decreased fat accumulation and inflammation in the liver.
The research team also studied how indole affected individual cells.
Shannon Glaser, M.D., a professor of Texas A&M Health Science Center, said that in addition to reducing the amount of fat in liver cells, indole also acts on cells in the intestine, which send out molecular signals that dampen inflammation.
"The link between the gut and the liver adds another layer of complexity to studies on non-alcoholic fatty liver disease, and future studies are very much needed to fully understand the role of indole," Glaser said.
Additional nutrition research needed
"Foods with a high capacity of indole production or medicines that mimic its effects may be new therapies for treatment of NAFLD," Wu said, adding prevention is another important aspect to consider.
"Preventing NAFLD's development and progression may depend on nutritional approaches to ensure that gut microbes allow indole and other metabolites to function effectively," he said. "Future research is needed to investigate how certain diets may be able to achieve this."
Wu said in future research he hopes to collaborate with food scientists and clinical nutritionists to examine what healthy foods can alter gut microbiota and increase indole production.
https://www.sciencedaily.com/releases/2020/02/200207123746.htm
Lower protein diet may lessen risk for cardiovascular disease
February 3, 2020
Science Daily/Penn State
A plant-based diet may be key to lowering risk for heart disease. Penn State researchers determined that diets with reduced sulfur amino acids -- which occur in protein-rich foods, such as meats, dairy, nuts and soy -- were associated with a decreased risk for cardiovascular disease. The team also found that the average American consumes almost two and a half times more sulfur amino acids than the estimated average requirement.
Amino acids are the building blocks of proteins. A subcategory, called sulfur amino acids, including methionine and cysteine, play various roles in metabolism and health.
"For decades it has been understood that diets restricting sulfur amino acids were beneficial for longevity in animals," said John Richie, a professor of public health sciences at Penn State College of Medicine. "This study provides the first epidemiologic evidence that excessive dietary intake of sulfur amino acids may be related to chronic disease outcomes in humans."
Richie led a team that examined the diets and blood biomarkers of more than 11,000 participants from a national study and found that participants who ate foods containing fewer sulfur amino acids tended to have a decreased risk for cardiometabolic disease based on their bloodwork.
The team evaluated data from the Third National Examination and Nutritional Health Survey. They compiled a composite cardiometabolic disease risk score based on the levels of certain biomarkers in participants' blood after a 10-16 hour fast including cholesterol, triglycerides, glucose and insulin.
"These biomarkers are indicative of an individual's risk for disease, just as high cholesterol levels are a risk factor for cardiovascular disease," Richie said. "Many of these levels can be impacted by a person's longer-term dietary habits leading up to the test."
Participants were excluded from the study if they reported having either congestive heart failure, heart attack or a reported change in diet due to a heart disease diagnosis. Individuals were also omitted if they reported a dietary intake of sulfur amino acids below the estimated average requirement of 15 mg/kg/day recommended by the Food and Nutrition Board of the National Academy of Medicine.
For a person weighing 132 pounds, food choices for a day that meet the requirement might include a medium slice of bread, a half an avocado, an egg, a half cup of raw cabbage, six cherry tomatoes, two ounces of chicken breast, a cup of brown rice, three quarters of a cup of zucchini, three tablespoons of butter, a cup of spinach, a medium apple, an eight inch diameter pizza and a tablespoon of almonds. Nutritionists collected information about participants' diets by doing in-person 24-hour recalls. Nutrient intakes were then calculated using the U.S. Department of Agriculture Survey Nutrient Database.
After accounting for body weight, the researchers found that average sulfur amino acid intake was almost two and a half times higher than the estimated average requirement. Xiang Gao, associate professor and director of the nutritional epidemiology lab at the Penn State University and co-author of the study, published today (Feb. 3) in Lancet EClinical Medicine, suggested this may be due to trends in the average diet of a person living in the United States.
"Many people in the United States consume a diet rich in meat and dairy products and the estimated average requirement is only expected to meet the needs of half of healthy individuals," Gao said. "Therefore, it is not surprising that many are surpassing the average requirement when considering these foods contain higher amounts of sulfur amino acids."
The researchers found that higher sulfur amino acid intake was associated with a higher composite cardiometabolic risk score after accounting for potential confounders like age, sex and history of diabetes and hypertension. They also found that high sulfur amino acid intake was associated with every type of food except grains, vegetables and fruit.
"Meats and other high-protein foods are generally higher in sulfur amino acid content," said Zhen Dong, lead author on the study and College of Medicine graduate. "People who eat lots of plant-based products like fruits and vegetables will consume lower amounts of sulfur amino acids. These results support some of the beneficial health effects observed in those who eat vegan or other plant-based diets."
Dong said that while this study only evaluated dietary intake and cardiometabolic disease risk factors at one point in time, the association between increased sulfur amino acid intake and risk for cardiometabolic disease was strong. She said the data supports the formation of a prospective, longitudinal study evaluating sulfur amino acid intake and health outcomes over time.
"Here we saw an observed association between certain dietary habits and higher levels of blood biomarkers that put a person at risk for cardiometabolic diseases," Richie said. "A longitudinal study would allow us to analyze whether people who eat a certain way do end up developing the diseases these biomarkers indicate a risk for."
https://www.sciencedaily.com/releases/2020/02/200203141501.htm
Eating red meat and processed meat hikes heart disease and death risk
Processed meats (stock image). Credit: © igor_kell / Adobe Stock
Eating red meat and processed meat hikes heart disease and death risk
February 3, 2020
Science Daily/Northwestern University
A large study links red and processed meat with higher risk of heart disease and death. Eating two servings of red meat, processed meat or poultry -- but not fish -- per week was linked to a 3 to 7 percent higher risk of cardiovascular disease. Eating two servings of red meat or processed meat -- but not poultry or fish -- per week was associated with a 3 percent higher risk of all causes of death.
After a controversial study last fall recommending that it was not necessary for people to change their diet in terms of red meat and processed meat, a large, carefully analyzed new study links red and processed meat consumption with slightly higher risk of heart disease and death, according to a new study from Northwestern Medicine and Cornell University.
Eating two servings of red meat, processed meat or poultry -- but not fish -- per week was linked to a 3 to 7% higher risk of cardiovascular disease, the study found. Eating two servings of red meat or processed meat -- but not poultry or fish -- per week was associated with a 3% higher risk of all causes of death.
"It's a small difference, but it's worth trying to reduce red meat and processed meat like pepperoni, bologna and deli meats," said senior study author Norrina Allen, associate professor of preventive medicine at Northwestern University Feinberg School of Medicine. "Red meat consumption also is consistently linked to other health problems like cancer."
"Modifying intake of these animal protein foods may be an important strategy to help reduce the risk of cardiovascular disease and premature death at a population level," said lead study author Victor Zhong, assistant professor of nutritional sciences at Cornell, who did the research when he was a postdoctoral fellow in Allen's lab.
The paper will be published Feb. 3 in JAMA Internal Medicine.
The new findings come on the heels of a controversial meta-analysis published last November that recommended people not reduce the amount of red meat and processed meat they eat. "Everyone interpreted that it was OK to eat red meat, but I don't think that is what the science supports," Allen said.
"Our study shows the link to cardiovascular disease and mortality was robust," Zhong said.
What should we eat?
"Fish, seafood and plant-based sources of protein such as nuts and legumes, including beans and peas, are excellent alternatives to meat and are under-consumed in the U.S.," said study coauthor Linda Van Horn, professor of preventive medicine at Feinberg who also is a member of the 2020 U.S. Dietary Guidelines Advisory committee.
The study found a positive association between poultry intake and cardiovascular disease, but the evidence so far isn't sufficient to make a clear recommendation about poultry intake, Zhong said. Still, fried chicken is not recommended.
The new study pooled together a large diverse sample from six cohorts, included long follow-up data up to three decades, harmonized diet data to reduce heterogeneity, adjusted a comprehensive set of confounders and conducted multiple sensitivity analyses. The study included 29,682 participants (mean age of 53.7 years at baseline, 44.4% men and 30.7% non-white). Diet data were self-reported by participants, who were asked a long list of what they ate for the previous year or month.
Key findings:
A 3 to 7% higher risk of cardiovascular disease and premature death for people who ate red meat and processed meat two servings a week.
A 4% higher risk of cardiovascular disease for people who ate two servings per week of poultry, but the evidence so far is not sufficient to make a clear recommendation about poultry intake. And the relationship may be related to the method of cooking the chicken and consumption of the skin rather than the chicken meat itself.
No association between eating fish and cardiovascular disease or mortality.
Limitations of the study are participants' dietary intake was assessed once, and dietary behaviors may have changed over time. In addition, cooking methods were not considered. Fried chicken, especially deep fat-fried sources that contribute trans-fatty acids, and fried fish intake have been positively linked to chronic diseases, Zhong said.
https://www.sciencedaily.com/releases/2020/02/200203114328.htm
Fermented soy products linked to lower risk of death
January 29, 2020
Science Daily/BMJ
A higher intake of fermented soy products, such as miso and natto, is associated with a lower risk of death, finds a study from Japan published by The BMJ today.
However, the researchers stress that the findings should be interpreted with caution as they may have been affected by unmeasured (confounding) factors.
In Asian countries, especially Japan, several types of soy products are widely consumed, such as natto (soybeans fermented with Bacillus subtilis), miso (soybeans fermented with Aspergillus oryzae), and tofu (soybean curd).
It is, however, still unclear whether different soy products, especially fermented soy products, are associated with specific health effects.
So a team of researchers in Japan set out to investigate the association between several types of soy products and death from any cause ("all cause mortality") and from cancer, total cardiovascular disease (heart disease and cerebrovascular disease), respiratory disease, and injury.
They base their findings on 42,750 men and 50,165 women aged 45-74 years who were taking part in a study based in 11 of Japan's public health centre areas.
Participants filled in detailed questionnaires about their dietary habits, lifestyle, and health status. Deaths were identified from residential registries and death certificates over a follow-up period of nearly 15 years.
The researchers found that a higher intake of fermented soy (natto and miso) was associated with a significantly lower (10%) risk of all cause mortality, but total soy product intake was not associated with all cause mortality.
Men and women who ate natto also had a lower risk of cardiovascular mortality than those who did not eat natto, but there was no association between soy intake and cancer related mortality.
These results persisted even after further adjusting for intake of vegetables, which was higher among those consuming larger portions of natto.
The authors point out that fermented soy products are richer in fibre, potassium and bioactive components than their non-fermented counterparts, which may help to explain their associations.
However, this is an observational study, so can't establish cause, and the researchers cannot rule out the possibility that some of the observed risk may be due to other unmeasured factors.
They conclude: "In this large prospective study conducted in Japan with a high rate of soy consumption, no significant association was found between intake of total soy products and all cause mortality. In contrast, a higher intake of fermented soy products (natto and miso) was associated with a lower risk of mortality."
Increasing evidence has suggested that fermented soy products are associated with health benefits, write researchers in a linked editorial. Whether people eat those products depends on their food culture, they say, but some countries already include soy and fermented soy products in their dietary guidelines.
Further studies are still required, however, "to refine our understanding of the health effects of fermented soy, and perhaps to inform the development of healthier and more palatable products," they conclude. "These efforts should be collaborative, including not only researchers but also policy makers and the food industry."
https://www.sciencedaily.com/releases/2020/01/200129212303.htm
Eating disorders linked to exercise addiction
New study is first to calculate risk factor
January 28, 2020
Science Daily/Anglia Ruskin University
New research shows that exercise addiction is nearly four times more common amongst people with an eating disorder.
The study, led by Mike Trott of Anglia Ruskin University (ARU), was published this month in the journal Eating and Weight Disorders -- Studies on Anorexia, Bulimia and Obesity.
The research is the first to measure rates of exercise addiction in groups of people with and without the characteristics of an eating disorder, The meta-analysis examined data from 2,140 participants across nine different studies, including from the UK, the US, Australia and Italy.
It found that people displaying characteristics of an eating disorder are 3.7 times more likely to suffer from addiction to exercise than people displaying no indication of an eating disorder.
Trott, a PhD researcher in Sport Science at Anglia Ruskin University (ARU), said: "It is known that those with eating disorders are more likely to display addictive personality and obsessive-compulsive behaviours. We are also aware that having an unhealthy relationship with food often means an increased amount of exercising, but this is the first time that a risk factor has been calculated.
"It is not uncommon to want to improve our lifestyles by eating healthier and doing more exercise, particularly at the start of the year. However, it is important to moderate this behaviour and not fall victim to 'crash diets' or anything that eliminates certain foods entirely, as these can easily lead to eating disorders.
"Our study shows that displaying signs of an eating disorder significantly increases the chance of an unhealthy relationship with exercise, and this can have negative consequences, including mental health issues and injury.
"Health professionals working with people with eating disorders should consider monitoring exercise levels as a priority, as this group have been shown to suffer from serious medical conditions as a result of excessive exercise, such as fractures, increased rates of cardiovascular disease in younger patients, and increased overall mortality."
https://www.sciencedaily.com/releases/2020/01/200128114642.htm
Weight loss and health improvements with Mediterranean, fasting & Paleo diets
January 23, 2020
Science Daily/University of Otago
There were some weight loss and health benefits for overweight adults who followed the Mediterranean, Intermittent Fasting and Paleo diets, though adherence to the diets dropped off considerably during the one-year study, new University of Otago research shows.
Intermittent fasting -- whereby participants limit their energy intake to about 25 per cent of their usual diet (500kcal for women and 600kcal for men) on two self-selected days per week, led to slightly more weight loss than the other diets. The Mediterranean diet also improved blood sugar levels.
Co-lead author Dr Melyssa Roy, a Research Fellow in the Department of Medicine, says the amount of weight loss was modest -- on average two to four kilograms for the 250 participants, but for those choosing the fasting or Mediterranean diets, clinically significant improvements in blood pressure were also seen.
The aim of the research was to examine how effective all three diets were in a "real world" setting, where participants self-selected which diet they wished to follow, without any ongoing support from a dietitian.
Dr Roy says the evidence shows that for some people the Mediterranean, fasting or paleo (Paleolithic) diets can be "healthful, beneficial ways to eat."
"This work supports the idea that there isn't a single 'right' diet -- there are a range of options that may suit different people and be effective. In this study, people were given dietary guidelines at the start and then continued with their diets in the real world while living normally. About half of the participants were still following their diets after a year and had experienced improvements in markers of health.
"Like the Mediterranean diet, intermittent fasting and paleo diets can also be valid healthy eating approaches -- the best diet is the one that includes healthy foods and suits the individual."
The Mediterranean diet encouraged consumption of fruit, vegetables, whole-grain breads and cereals, legumes, nuts, seeds and olive oil with moderate amounts of fish, chicken, eggs and diary and red meat once a week or less.
The paleo diet consists of mostly less-processed foods with an emphasis on eating fruit and vegetables, animal proteins, nuts, coconut products and extra-virgin olive oil. While "original" Paleo diets strictly exclude all legumes, dairy and grains, this study used a modified version including some dairy as well as up to one serving daily of legumes and grain-based food.
Co-lead author Dr Michelle Jospe, a Postdoctoral Fellow in the Department of Medicine, says the results showed people found the Mediterranean diet to be the easiest to adhere to.
"Our participants could follow the diet's guidelines more closely than the fasting and paleo diets and were more likely to stay with it after the year, as our retention rates showed."
Most of the 250 participants (54 per cent) chose the fasting diet, while 27 per cent chose the Mediterranean and 18 per cent the paleo. After 12 months, the Mediterranean diet had the best retention rate with 57 per cent of participants continuing, with 54 per cent still fasting and 35 per cent still on the paleo diet.
After 12 months, the average weight loss was 4.0kg for those choosing the fasting diet, 2.8kg on the Mediterranean diet and 1.8kg on the paleo diet.
Reduced systolic blood pressure was observed among those participating in the fasting and Mediterranean diets, together with reduced blood sugar levels in the Mediterranean diet.
Dr Jospe explains participants who said they were still following their diet at 12 months lost even more weight, showing the importance of choosing a diet that is sustainable.
She believes the results of this study are relevant to the thousands of people following self-chosen diets with little supervision and indicates more realistic outcomes.
https://www.sciencedaily.com/releases/2020/01/200123170721.htm
Teens with obesity and PCOS have more 'unhealthy' bacteria
Gut microbiome may play a role in PCOS and its related metabolic complications
January 23, 2020
Science Daily/The Endocrine Society
Teens with obesity and polycystic ovary syndrome (PCOS) have more "unhealthy" gut bacteria suggesting the microbiome may play a role in the disorder, according to new research published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.
PCOS is complicated endocrine disorder affecting 6 percent to 18 percent of women of reproductive age and work in adult women indicates that changes in bacteria be involved. The. The hormone disorder is characterized by elevated testosterone levels in the blood that cause acne, excess hair growth and irregular periods. Teens with PCOS often also struggle with obesity and have a higher risk for type 2 diabetes, infertility, and depression.
"We found that in adolescents with PCOS and obesity, the bacterial profile (microbiome) from stool has more "unhealthy" bacteria compared to teens without PCOS," said the study's corresponding author, Melanie Cree Green, M.D., Ph.D., of Children's Hospital Colorado in Aurora, Colo. "The unhealthy bacteria related to higher testosterone concentrations and markers of metabolic complications."
The researchers studied 58 teens with obesity and found that girls with PCOS have an altered gut microbiome compared to those without the condition. These girls had more "unhealthy" bacteria in their stool which was related to higher testosterone levels and other markers of metabolic syndrome, such as higher blood pressure, liver inflammation and plasma triglycerides
"The gut microbiome may play a role in PCOS and its related metabolic complications, and these changes can be found in teenagers who are early in the course of the condition," Green said.
https://www.sciencedaily.com/releases/2020/01/200123090342.htm
Walnuts may be good for the gut and help promote heart health
January 16, 2020
Science Daily/Penn State
Researchers found that eating walnuts daily as part of a healthy diet was associated with increases in certain bacteria that can help promote health. Additionally, those changes in gut bacteria were associated with improvements in some risk factors for heart disease.
Walnuts may not just be a tasty snack, they may also promote good-for-your-gut bacteria. New research suggests that these "good" bacteria could be contributing to the heart-health benefits of walnuts.
In a randomized, controlled trial, researchers found that eating walnuts daily as part of a healthy diet was associated with increases in certain bacteria that can help promote health. Additionally, those changes in gut bacteria were associated with improvements in some risk factors for heart disease.
Kristina Petersen, assistant research professor at Penn State, said the study -- recently published in the Journal of Nutrition -- suggests walnuts may be a heart- and gut-healthy snack.
"Replacing your usual snack -- especially if it's an unhealthy snack -- with walnuts is a small change you can make to improve your diet," Petersen said. "Substantial evidence shows that small improvements in diet greatly benefit health. Eating two to three ounces of walnuts a day as part of a healthy diet could be a good way to improve gut health and reduce the risk of heart disease."
Previous research has shown that walnuts, when combined with a diet low in saturated fats, may have heart-healthy benefits. For example, previous work demonstrated that eating whole walnuts daily lowers cholesterol levels and blood pressure.
According to the researchers, other research has found that changes to the bacteria in the gastrointestinal tract -- also known as the gut microbiome -- may help explain the cardiovascular benefits of walnuts.
"There's a lot of work being done on gut health and how it affects overall health," said Penny Kris-Etherton, distinguished professor of nutrition at Penn State. "So, in addition to looking at factors like lipids and lipoproteins, we wanted to look at gut health. We also wanted to see if changes in gut health with walnut consumption were related to improvements in risk factors for heart disease."
For the study, the researchers recruited 42 participants with overweight or obesity who were between the ages of 30 and 65. Before the study began, participants were placed on an average American diet for two weeks.
After this "run-in" diet, the participants were randomly assigned to one of three study diets, all of which included less saturated fat than the run-in diet. The diets included one that incorporated whole walnuts, one that included the same amount of alpha-linolenic acid (ALA) and polyunsaturated fatty acids without walnuts, and one that partially substituted oleic acid (another fatty acid) for the same amount of ALA found in walnuts, without any walnuts.
In all three diets, walnuts or vegetable oils replaced saturated fat, and all participants followed each diet for six weeks with a break between diet periods.
To analyze the bacteria in the gastrointestinal tract, the researchers collected fecal samples 72 hours before the participants finished the run-in diet and each of the three study diet periods.
"The walnut diet enriched a number of gut bacteria that have been associated with health benefits in the past," Petersen said. "One of those is Roseburia, which has been associated with protection of the gut lining. We also saw enrichment in Eubacteria eligens and Butyricicoccus."
The researchers also found that after the walnut diet, there were significant associations between changes in gut bacteria and risk factors for heart disease. Eubacterium eligens was inversely associated with changes in several different measures of blood pressure, suggesting that greater numbers of Eubacterium eligens was associated with greater reductions in those risk factors.
Additionally, greater numbers of Lachnospiraceae were associated with greater reductions in blood pressure, total cholesterol, and non-HDL cholesterol. There were no significant correlations between enriched bacteria and heart-disease risk factors after the other two diets.
Regina Lamendella, associate professor of biology at Juniata College, said the findings are an example of how people can feed the gut microbiome in a positive way.
"Foods like whole walnuts provide a diverse array of substrates -- like fatty acids, fiber and bioactive compounds -- for our gut microbiomes to feed on," Lamendella said. "In turn, this can help generate beneficial metabolites and other products for our bodies."
Kris-Etherton added that future research can continue to investigate how walnuts affect the microbiome and other elements of health.
"The findings add to what we know about the health benefits of walnuts, this time moving toward their effects on gut health," Kris-Etherton said. "The study gives us clues that nuts may change gut health, and now we're interested in expanding that and looking into how it may affect blood sugar levels."
https://www.sciencedaily.com/releases/2020/01/200116112542.htm
Obesity crisis blamed for a rise in fatty liver disease amongst young adults
January 15, 2020
Science Daily/University of Bristol
One in five young people have fatty liver disease (steatosis), with one in 40 having already developed liver scarring (fibrosis), research published today [15 January] has found. The study, published in The Lancet Gastroenterology & Hepatology, is the first to attempt to determine the prevalence of fatty liver disease and fibrosis in young healthy adults in the UK.
Fatty liver disease is a condition in which fats build up in the cells of the liver. It is broadly split into non-alcoholic fatty liver disease (NAFLD), which is usually seen in people who are overweight or obese, and alcohol related fatty liver disease, which is associated with harmful levels of drinking. If left untreated both can lead to fibrosis (scarring of the liver) and in severe cases eventually cirrhosis of the liver, which is irreversible. Worldwide NAFLD affects approximately a quarter of adults in developed countries.
The research, conducted by Dr Kushala Abeysekera and researchers from the University of Bristol, looked at data collected from 4,021 participants of the Children of the 90s study also known as Avon Longitudinal Study of Parents and Children (ALSPAC). Based in Bristol, participants from the health study -- who had previously been assessed for NAFLD as teenagers using ultrasound -- were invited for assessment using transient elastography with FibroScan as part of the Focus @24 clinic.
Researchers first looked at those participants who did not report harmful alcohol consumption and found that one in five had non-alcoholic fatty liver disease. On widening the data to include all participants, they again found that over 20 per cent displayed evidence of fatty liver and one in 40 had already developed fibrosis, with those participants who had both fatty liver and harmful alcohol use at greatest risk of liver scarring. As a comparison, at 17 years of age, 2.5 per cent of participants had moderate to severe levels of fatty liver, whilst at the age of 24 this number had increased to 13 per cent.
Dr Abeysekera, Honorary Lecturer in the Bristol Medical School: Population Health Sciences, explained: "Children of the 90s data has highlighted the potential importance of liver health amongst young adults. This age group remains a blind spot for clinicians, as they are typically considered a "healthy" age group that are rarely studied. If the obesity epidemic and culture of alcohol abuse aren't tackled nationally, we may see increasing numbers of patients presenting with end-stage liver disease, and at earlier ages.
"It is important to note that whilst we identified that 20 per cent of the cohort had fatty liver -- only a small percentage of the individuals will go on to develop cirrhosis (irreversible liver scarring), and the vast majority of participants should be fine if they manage their diet and exercise appropriately."
The next steps will be to take a closer look at how environmental and genetic factors may lead to individuals developing non-alcoholic fatty liver disease earlier in life.
https://www.sciencedaily.com/releases/2020/01/200115191527.htm
Drinking 1% rather than 2% milk accounts for 4.5 years of less aging in adults
High-fat milk consumption is connected to significantly shorter telomeres
January 15, 2020
Science Daily/Brigham Young University
A new study shows drinking low-fat milk -- both nonfat and 1% milk -- is significantly associated with less aging in adults.
Research on 5,834 U.S. adults by Brigham Young University exercise science professor Larry Tucker, Ph.D., found people who drink low-fat milk experience several years less biological aging than those who drink high-fat (2% and whole) milk.
"It was surprising how strong the difference was," Tucker said. "If you're going to drink high-fat milk, you should be aware that doing so is predictive of or related to some significant consequences."
Tucker investigated the relationship between telomere length and both milk intake frequency (daily drinkers vs. weekly drinkers or less) and milk fat content consumed (whole vs. 2% vs. 1% vs. skim). Telomeres are the nucleotide endcaps of human chromosomes. They act like a biological clock and they're extremely correlated with age; each time a cell replicates, humans lose a tiny bit of the endcaps. Therefore, the older people get, the shorter their telomeres.
And, apparently, the more high-fat milk people drink, the shorter their telomeres are, according to the new BYU study, published in Oxidative Medicine and Cellular Longevity. The study revealed that for every 1% increase in milk fat consumed (drinking 2% vs. 1% milk), telomeres were 69 base pairs shorter in the adults studied, which translated into more than four years in additional biological aging. When Tucker analyzed the extremes of milk drinkers, adults who consumed whole milk had telomeres that were a striking 145 base pairs shorter than non-fat milk drinkers.
Nearly half of the people in the study consumed milk daily and another quarter consumed milk at least weekly. Just under a third of the adults reported consuming full-fat (whole) milk and another 30 percent reported drinking 2% milk. Meanwhile, 10% consumed 1% milk and another 17% drank nonfat milk. About 13% did not drink any cow milk.
"Milk is probably the most controversial food in our country," Tucker said. "If someone asked me to put together a presentation on the value of drinking milk, I could put together a 1-hour presentation that would knock your socks off. You'd think, 'Whoa, everybody should be drinking more milk.' If someone said do the opposite, I could also do that. At the very least, the findings of this study are definitely worth pondering. Maybe there's something here that requires a little more attention."
Somewhat surprisingly, he also found that milk abstainers had shorter telomeres than adults who consumed low-fat milk.
Tucker said the study findings provide support for the current Dietary Guidelines for Americans (2015-2020), which encourage adults to consume low-fat milk, both nonfat and 1% milk, and not high-fat milk, as part of a healthy diet.
"It's not a bad thing to drink milk," Tucker said. "You should just be more aware of what type of milk you are drinking."
https://www.sciencedaily.com/releases/2020/01/200115120634.htm