Additional benefit of omega-3 fatty acids for the clearance of metabolites from the brain
October 26, 2016
Science Daily/Federation of American Societies for Experimental Biology
Omega-3 polyunsaturated fatty acids, which are found in fish oil, could improve the function of the glymphatic system, which facilitates the clearance of waste from the brain, and promote the clearance of metabolites including amyloid-? peptides, a primary culprit in Alzheimer's disease, report scientists.
To make this discovery, scientists first used transgenic fat-1 mice, which express high endogenous omega-3 polyunsaturated fatty acids (PUFAs) in the brain, to investigate the effect of omega-3 PUFAs on the clearance function of the glymphatic system. Compared to the wild-type mice, the fat-1 mice with enriched endogenous omega-3 PUFAs significantly promote the clearance function of the lymphatic system, including the Aβ clearance from the brain. Wild-type mice were supplemented with fish oil, which contains high concentrations of omega-3 PUFAs, and found that fish oil-supplemented mice also improved the clearance function of the glymphatic system compared to the control mice without fish oil supplementation. Omega-3 PUFAs help maintain the brain homeostasis, which may provide benefits in a number of neurological diseases, such as Alzheimer's disease, traumatic brain injury, and sleep impairment, among others.
"These now-famous fatty acids have been the subject of major studies both in academia and industry. Just when we thought we had heard everything, here is something new, and it is provocative indeed," said Thoru Pederson, Ph.D., Editor-in-Chief of The FASEB Journal. "This study should not turn attention away from the roles of these substances in maintaining vascular health, but neither should they restrict our view. The brain is an extremely vascularized organ, while we might also bear in mind that omega-3 fatty acids may impact neurons, glia, and astrocytes themselves."
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/10/161026105336.htm
High blood pressure can impair cognitive function, pose risk for Alzheimer's
October 26, 2016
Science Daily/Loyola University Health System
High blood pressure in middle age can lead to impaired cognition and is a potential risk factor for Alzheimer’s disease, researchers conclude.
Dr. Biller is a member of the multidisciplinary panel of experts that wrote the statement, published in the heart association journal Hypertension. Dr. Biller is chair of the department of neurology of Loyola University Chicago Stritch School of Medicine. The panel is chaired by Constantino Iadecola, MD, of Weill Cornell Medicine and co-chaired by Kristine Yaffe, MD, of the University of California San Francisco.
Dementia affects an estimated 30 to 40 million people worldwide, and the number is expected to triple by 2050 due to an aging population and other factors.
An estimated 80 million people in the United States have hypertension, and the brain is among the organs most affected. Except for age, hypertension is the most important risk factor for vascular problems in the brain that lead to stroke and dementia.
There is consistent evidence that chronic high blood pressure during middle age (40 to 64) is associated with altered cognitive function in both middle age and late life (65 to 84). Cognitive abilities that are affected include memory, speed of processing and executive function (ability to organize thoughts, manage time, make decisions, etc.)
The effect of high blood pressure in late life is less clear. Some studies suggest it's harmful, while other research suggests it may improve cognition. This highlights "the complexities of recommending uniform levels of blood pressure across the life course," the expert panel wrote.
Observational studies have demonstrated that high blood pressure causes atherosclerosis (hardening of the arteries) and other damage to the brain's blood vessels, leading to reduced blood flow to brain cells. But evidence from clinical trials that treating blood pressure improves cognition is not conclusive.
After carefully reviewing available studies, the panel concluded there are not enough data to make evidence-based recommendations. However, judicious treatment of high blood pressure, taking into account goals of care and the patient's individual characteristics, "seems justified to safeguard vascular health and, as a consequence, brain health," the panel concluded.
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/10/161026142208.htm
Power outage in the brain may be source of Alzheimer's
Restoring damaged genes linked to mitochondrial function may offer strategy for halting disease advance
November 9, 2016
Science Daily/Arizona State University
In a new study, researchers investigate the role of mitochondria in Alzheimer's disease pathology. Mitochondria act as energy centers for cells and are of central importance in health and disease. The study builds on earlier work suggesting gene mutations affecting mitochondrial function may be critical in the development of the disease.
On Nov. 25, 1901, a 51-year-old woman is admitted to a hospital in Frankfurt, Germany, displaying a bizarre constellation of symptoms. Her behavior is erratic. She shows signs of paranoia as well as auditory hallucinations, disorientation and severe memory impairment. Asked to write her own name, she manages "Mrs.," then lingers over the page, unable to remember the rest. "I have lost myself," she tells the attending physician.
Over time, she will withdraw into her own inscrutable universe, before dying on April 9, 1906.
The tragic case of Auguste Deter might have vanished into the recesses of medical history, but for the following fact: Her doctor, Alois Alzheimer, made a thorough examination of her medical condition, including her excised brain, discovering the telltale amyloid plaques and neurofibrillary tangles characteristic of her illness. Auguste Deter was the first person diagnosed with Alzheimer's disease.
Today, society faces an epidemic of Alzheimer's, with some 5 million afflicted in the U.S. alone. The number is projected to swell to 14 million by midcentury, according to the Centers for Disease Control and Prevention. Of the top 10 leading fatal illnesses, Alzheimer's remains the only one that cannot be prevented, treated or cured.
In new research appearing in the journal Alzheimer's and Dementia, Diego Mastroeni, Paul Coleman and their colleagues at the ASU-Banner Neurodegenerative Disease Research Center (NDRC) and the Biodesign Center for Bioenergetics investigate the role of mitochondria in Alzheimer's disease pathology. Mitochondria act as energy centers for cells and are of central importance in health and disease.
The study builds on earlier work suggesting gene mutations affecting mitochondrial function may be critical in the development -- and pitiless progression -- of the disease.
"Age-related neurodegenerative diseases, like Alzheimer's, progress over a long period of time before they become clinically apparent. The earliest physiological and molecular events are largely unknown," said Mastroeni. "Findings from our laboratory have uncovered early expression changes in nuclear-encoded, but not mitochondrial-encoded mRNAs occurring in one's early 30s, giving us a glimpse into what we suspect are some of the earliest cellular changes in the progression of Alzheimer's disease."
Results of the new study show that specific classes of genes associated with mitochondrial cell respiration display reduced expression levels in patients with Alzheimer's disease, compared with normal patients.
The study also examines gene expression in subjects whose brains show an intermediate level of illness known as mild cognitive impairment. Here, the opposite effect is observed, with relevant genes exhibiting increased levels of expression. The authors suggest this observation may point to some kind of compensatory mechanism in the brain attempting to stave off the disease in its earlier stages.
Further, the study proposes that restoring a specific set of damaged genes linked to mitochondrial function and located in the nuclear DNA of cells may offer a promising strategy for halting the disease's advance.
Assault on identity
Alzheimer's -- the most common form of dementia -- is a progressive, degenerative disease of the brain. While commonly associated with elderly individuals, this devastating illness is now believed to have its origins much earlier, infiltrating the nervous system decades before the onset of clinical symptoms. Indeed, the greatest obstacle to successful treatment of Alzheimer's is the fact that the disease is typically not recognized until its progress has irreparably ravaged the brain.
The disease often begins with mild memory loss, which may interfere with normal conversation. While advancing age remains the leading risk factor for Alzheimer's, some individuals are also genetically predisposed. Other risk factors include high cholesterol, heart disease, stroke and high blood pressure. Today, Alzheimer's is the fifth-leading cause of death in adults 65-85 years old.
Despite the increasingly pronounced effects of dementia, a definitive diagnosis of Alzheimer's disease usually requires the post-mortem examination of brain tissue and identification of two stereotypic symptoms, known as plaques and tangles. More recently, new imaging technology has enabled researchers to detect these symptoms in living brains, though Coleman is cautious about their interpretation:
"Although plaques and tangles remain as the definitive neuropathological hallmark of the disease, plaques do not correlate at all with degree of cognitive impairment in [Alzheimer's] and tangles correlate only slightly," he said. "We further know that plaques and tangles are late comers in the cascade of events that cause the dementia of [Alzheimer's]."
Alzheimer's is believed to account for 60-70 percent of dementia cases. As the disease progresses, symptoms become more severe, including erosion of language ability, physical disorientation and behavioral transformations, often involving the withdrawal from family and society. Over time, bodily functions are lost, ultimately leading to death. Life expectancy for Alzheimer's patients varies, but three to nine years following diagnosis is typical.
Quick energy
Mitochondria -- membrane-bound organelles found in all eukaryotic organisms -- are often called the powerhouses of the cell. Through a process known as oxidative phosphorylation, they produce most of the cell's chemical energy in the form of adenosine triphosphate or ATP.
In addition to supplying cellular energy, mitochondria are involved in cell signaling, cellular differentiation and cell death, as well as in cellular growth and the maintenance of the cell cycle.
Because mitochondria play such an important role in the cell, mitochondrial dysfunction has been implicated in a broad range of illness, including cardiovascular disease, autism, schizophrenia, bipolar disorder, epilepsy, stroke, Lou Gehrig's disease and diabetes along with forms of dementia including Alzheimer's.
Unsurprisingly, defects in mitochondrial function more severely affect energy-hungry organ systems in the body, particularly muscles, the GI tract and the brain -- an organ making up just 2 percent of a person's weight while consuming 20 percent of the body's total energy budget.
Mitochondria are unique among the cell's organelles, as they possess their own DNA, distinct from the DNA contained within the cell's nucleus. This strange state of affairs is due to mitochondrial evolution. Mitochondria are descended from free-living bacteria that colonized other cells some 2 billion years ago. After being incorporated into nucleated cells, these endosymbionts, as they are known, lost much of their original machinery, yet retained their own complement of DNA.
In addition to the role of mitochondrial dysfunction in disease, the gradual degradation of mitochondrial integrity is believed to play a central role in the normal process of aging.
Broken genes
The current study examines tissue from the hippocampus, a structure critical for memory and one severely impacted by the advance of Alzheimer's. Using microarray technology, the authors examined hippocampal tissue from an aging cohort-44 normal brains from 29-99 years of age, 10 with mild cognitive impairment and 18 with Alzheimer's disease.
Gene expression was examined for two sets of genes, 1 encoding mitochondrial DNA and the other, in the nuclear DNA. The two sets of genes both coded for proteins associated with a mitochondrial complex essential for oxidative phosphorylation (OXPHOS), producing energy in the form of ATP for the cell.
Intriguingly, while the mitochondrial genes themselves were largely unaffected, the nuclear genes associated with the OXPHOS complex underwent significant modification, depending on the tissues examined. The microarray data revealed substantial down-regulation of nuclear-encoded OXPHOS genes in Alzheimer's tissue, a finding also found in normally aging brains.
The same genes, however, were up-regulated in the case of mild cognitive impairment, a precursor to Alzheimer's disease. The authors suggest this effect may be due to a compensatory mechanism in the brain in response to early pathology.
The findings are consistent with earlier work establishing that accumulations of amyloid beta (Aβ) in neurons, a hallmark of Alzheimer's, are directly implicated in mitochondrial dysfunction. The pronounced effect on nuclear-encoded but not mitochondrial-encoded OXPHOS genes may point to dysfunctions in the transport of molecules from the cell nucleus to the mitochondria.
"Our work on mitochondria offers the promise of a reliable marker appearing earlier in the course of the disease -- one which more closely correlates with the degree of dementia than the current diagnostic of plaques and tangles," Coleman said.
Precise mechanisms of mitochondrial decline in aging and Alzheimer's have yet to be teased out and will be the focus of continuing research. The study suggests that therapies aimed at restoring function in nuclear-encoded OXPHOS genes may provide an exciting new avenue for treatment of Alzheimer's.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/11/161109175141.htm
New findings on physical activity could shape treatment for mild Alzheimer's disease
November 9, 2016
Science Daily/University of Kansas
For older adults, physical activity is apt to shield against cognitive decline and forms of dementia such as Alzheimer's disease (AD). Yet, as people age and some experience cognitive impairment, they tend to become less physically active.
"Physical activity is very important for brain function," said Amber Watts, assistant professor of clinical psychology at the University of Kansas. "We know that people who are physically active are less likely to develop AD. But we also know that for people already living with AD, physical activity can help them function better, decline more slowly and help them with symptoms like agitation, wandering and sleeplessness."
According to Watts, too little is known about patterns of activity for people experiencing the early stages of AD. For instance, researchers have lacked useful data about how the progression of the disease itself plays a role in diminishing day-to-day physical activity.
"Part of the issue is they're a difficult population to study," she said. "It's mostly assumed that they're not active, that they don't engage in physical activity, but our research showed people in early stages of AD are capable of being active -- they just need assistance."
Watts, who researches health behaviors, prevention strategies and bio-behavioral processes tied to cognitive decline and dementia, wanted to know if there were differences in physical activity between the two groups.
She recently co-authored research appearing in the peer-reviewed Journal of Alzheimer's Disease that used state-of-the-art accelerometers to track daily physical activity of healthy people and those in the early stage of AD.
"In researching physical activity, people in the past have collected data using body-worn devices like Fitbit and accelerometers that collect data every second," Watts said. "But instead of using all the data, they've summed it into one score over the entire time the person was wearing the device. What we've done is look at variability in physical activity over course of the entire day. This may help us to customize interventions, and it may help us to understand disrupted sleep cycles as well."
With colleague Vijay R. Varma of the National Institute on Aging, Watts analyzed daily physical activity of 92 volunteers with and without AD at KU's Alzheimer's Disease Center in Kansas City. Participants wore Actigraph GT3X+ accelerometers for a week.
"We found people with AD have different daily patterns of activity than people without AD," Watts said. "They spend less time in moderate-intensity activity. But it has to do with time of day. They're a lot less active in the morning, when most people are at the peak of activity -- and that may influence caregivers and people who are trying to help people with dementia."
The KU researcher said understanding this different daily pattern in physical activity could be key to designing interventions and improving sleep for people with early AD, perhaps by targeting more physical activity in morning.
Watts said the kinds of physical activity found to be helpful to people with AD might be as simple as finding time to walk around the neighborhood. Her past research includes studies on the benefits of walkable communities for older adults.
"Walking is actually the best thing," she said. "It's low risk, it's safe, anyone can do it, it doesn't require specific equipment, it can be done anywhere. There are other light-intensity activities like stretching, tai chi, household chores, gardening, walking around the mall -- those are also beneficial. People with AD don't have to go to the gym, they just need to do something that keeps them moving and keeps them from sitting continuously."
Challenges for people with AD to getting physically active include changes to what researchers call "motor planning" that come along with typical symptoms of mild AD, even though gross motor function is largely preserved.
"That's the ability to plan out what movements they will do," Watts said. "There's an interaction between cognitive features and motor features. If you have difficulty with cognition, you have trouble with motor function. For instance, if you want to walk, but fear getting lost, you are reluctant because you need cognition to guide motor behavior. In early stages of AD, people are still high functioning physically, but they perceive it's more difficult to get physically active."
Watts will present her latest findings to the annual meeting of the Gerontological Society of America in New Orleans on Nov. 16.
She's following up the research with a larger study of volunteers from KU's Alzheimer's Disease Center, which is headed by colleague Jeffrey Burns.
"There will be hundreds who wear accelerometers for two weeks at a time, collecting data, and we'll look at both sleep and physical activity," Watts said. "So we're continuing this line of research to find out more. We're especially interested in how nighttime sleep and daytime activity levels interact and influence one another."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/11/161109114243.htm
Healthy living means better brain function
November 9, 2016
Science Daily/Frontiers
A feedback loop exists between greater executive function and healthy behavior, scientists report. Specifically, individuals with poor executive function showed subsequent decreases in their rates of participation in physical activity and older adults who engaged in sports and other physical activities tended to retain high levels of executive function over time.
But new research suggests living a healthier lifestyle could also increase executive function, which is the ability to exert self-control, set and meet goals, resist temptation and solve problems. In effect, the study suggests a feedback loop exists where greater executive function enables people to lead a healthier lifestyle, which in turn, improves their executive function.
"It seems that physical activity and EF are synergistic -- they improve one another," according to the study, titled "A Bidirectional Relationship between Executive Function and Health Behaviors."
The study, published by researchers at the University of Aberdeen, the University of Stirling and the University College Dublin, used data collected from 4,555 adults through the English Longitudinal Study of Aging. Researchers analyzed the relationship between physical activity and executive function, adjusting for other variables such as age, gender, education, wealth and illness and found evidence that the relationship between the two is bidirectional. It is the first study of its kind to look at whether the effects are bidirectional and has expanded the understanding of such relationships.
Specifically, individuals with poor executive function showed subsequent decreases in their rates of participation in physical activity and older adults who engaged in sports and other physical activities tended to retain high levels of executive function over time.
Researchers noted that while the study focused on physical activity and its relationship to executive function, it's likely a positive feedback loop also exists between executive function and eating nutritious foods.
Similarly, it is likely that negative feedback loops also exist, in that unhealthy behaviors such as smoking or drinking too much alcohol will be both a result of and a predictor of declining executive function. This has implications, according to the study, for aging.
The older one gets, the more likely executive function is to decline, the study notes. Older people, then, may become more likely to engage in unhealthy behaviors like remaining sedentary and less likely to maintain healthy but effortful behaviors like taking prescribed medication regularly. Conversely, the longer one can maintain high executive function, the longer and more easily that person can stave off behavior that will be detrimental to their health.
Dr. Julia Allan suggests that "people who make a change to their health behavior, like participating in physical activity, eating less processed food, or consuming more fruits and vegetables, can see an improvement in their brain function over time and increase their chances of remaining healthy as they age."
That may be why, researchers opined, those with higher executive function tend to avoid chronic illnesses and live longer after a chronic diagnosis than those who have weaker executive function. With the world's population of elderly folks to hit 1.5 billion by 2050, as the study notes, the research could have major implications for the future of health care.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/11/161109113054.htm
Alzheimer's disease found to be a diabetic disorder of the brain
November 9, 2016
Science Daily/Tohoku University
A promising treatment for Alzheimer's disease has been found by researchers who noticed a similarity in the way insulin signaling works in the brain and in the pancreas of diabetic patients.
"In the pancreas, the Kir6.2 channel blockade increases the insulin signaling, and insulin signaling decreases the blood glucose levels," says Dr. Shigeki Moriguchi. "In the brain, insulin signaling increases the acquisition of memory through CaM kinase II activation by Kir6.2 channel blockade."
The research group, led by Dr. Moriguchi and Professor Kohji Fukunaga of the Graduate School of Pharmaceutical Sciences, thus concluded that Alzheimer's disease can be described as a diabetic disorder of the brain.
Memantine, a drug widely used to treat Alzheimer's disease, is a well known inhibitor of the N-methyl-D-aspartate (NMDA) receptors that prevent excessive glutamate transmission in the brain. Researchers have now found that memantine also inhibits the ATP-sensitive potassium channel (Kir6.2 channel), improving insulin signal dysfunction in the brain.
In their experiment with mice, the researchers found that memantine treatment improved impaired hippocampal long-term potentiation (LTP) and memory-related behaviors in the mice through the inhibition of KATP channel Kir6.2.
"Since KATP channels Kir6.1 or Kir6.2 are critical components of sulfonylurea receptors (SURs) which is downstream insulin receptor signaling, the KATP channel inhibition by Memantine mediates the anti-diabetic drug action in peripheral tissues," says Dr. Moriguchi. "And this leads to improved cognitive functions and improved memory retention among Alzheimer's patients."
The researchers now hope that results of their study and the parallels drawn with diabetes, will lead to new treatments for Alzheimer's disease, using the inhibition of Kir6.2 channel.
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/11/161109111922.htm
Researchers reveal how neurodegenerative diseases spread through the brain
November 9, 2016
Science Daily/VIB - Flanders Interuniversity Institute for Biotechnology
Synapses, the place where brain cells contact one another, play a pivotal role in the transmission of toxic proteins. This allows neurodegenerative diseases such as Alzheimer’s to spread through the brain, scientists conclude. If the spreading of these toxic proteins could be prevented, the progression of neurodegenerative diseases might be slowed down substantially.
During neurodegenerative disease, including Alzheimer's, toxic proteins are known to spread throughout the brain. As the disease progresses, more and more brain areas are affected.
Prof. Patrik Verstreken (VIB-KU Leuven): "You can compare it to a drop of ink that falls into a glass of water: gradually, the toxic proteins diffuse through the brain. We knew that the disease follows the existing brain paths but so far it wasn't clear which processes enabled the spread itself."
Genetic risk factors
The researchers now offer proof that synapses are critical to mediate the transmission of toxic protein species and reveal the mechanisms behind this process. They show that the toxic proteins cross from one brain cell to the next by being engulfed by 'vesicles', small bubbles in the receiving brain cell. There the vesicles burst and release the toxic proteins.
Prof. Patrik Verstreken (VIB-KU Leuven): "We also show how familial history has an impact on this process. There are known genetic factors in the human population that increase the risk to develop Alzheimer's and we show that one of the more common genetic variants, dubbed 'BIN1', directly affects the transmission of toxic proteins at synapses. BIN1 'improves' the transmission at synapses but in doing so, it enables the spread of toxic proteins."
Next steps
These findings open new perspectives for the treatment of neurodegenerative diseases. By understanding how toxic proteins are passed on between brain cells, researchers may also be able to identify therapeutic avenues to block this process or to shuttle the toxic proteins to the cellular "waste bins."
Dr. Dieder Moechars (Scientific Director at Janssen Research & Development): "Our work is based on in vitro experiments, so it will now be critical to put our models to the test in in vivo models of Alzheimer's disease. Knowing the mechanism of spreading, we now need to devise clever ways to interfere with it."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/11/161109085807.htm
Who has the better memory, men or women?
November 9, 2016
Science Daily/The North American Menopause Society (NAMS)
Middle-aged women may remember more than men, but their memory fades as estrogen levels decline, report researchers.
In the battle of the sexes, women have long claimed that they can remember things better and longer than men can. A new study proves that middle-aged women outperform age-matched men on all memory measures, although memory does decline as women enter postmenopause. The study is being published online in Menopause, the journal of The North American Menopause Society (NAMS).
Memory loss, unfortunately, is a well-documented consequence of the aging process. Epidemiological estimates suggest that approximately 75% of older adults report memory-related problems. Women report increased forgetfulness and "brain fog" during the menopause transition. In addition, women are disproportionately at risk for memory impairment and dementia compared with men. Despite these conditions working against them, middle-aged women still outscore their similarly aged male counterparts on all memory measures, according to the study.
The cross-sectional study of 212 men and women aged 45 to 55 years assessed episodic memory, executive function, semantic processing, and estimated verbal intelligence through cognitive testing. Associative memory and episodic verbal memory were assessed using a Face-Name Associative Memory Exam and Selective Reminding Test.
In addition to comparing sex differences, the study also found that premenopausal and perimenopausal women outperformed postmenopausal women in a number of key memory areas. Declines in estradiol levels in postmenopausal women were specifically associated with lower rates of initial learning and retrieval of previously recalled information, while memory storage and consolidation were maintained.
"Brain fog and complaints of memory issues should be taken seriously," says Dr. JoAnn Pinkerton, NAMS executive director. "This study and others have shown that these complaints are associated with memory deficits."
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/11/161109112447.htm
Probiotics improve cognition in Alzheimer's patients
November 10, 2016
Science Daily/Frontiers
For the first time, scientists have shown that probiotics -- beneficial live bacteria and yeasts taken as dietary supplements -- can improve cognitive function in humans. In a new clinical trial, scientists show that a daily dose of probiotic Lactobacillus and Bifidobacterium bacteria taken over a period of just 12 weeks is enough to yield a moderate but significant improvement in the score of elderly Alzheimer's patients on the Mini-Mental State Examination (MMSE) scale, a standard measure of cognitive impairment.
Probiotics are known to give partial protection against certain infectious diarrheas, irritable bowel syndrome, inflammatory bowel disease, eczema, allergies, colds, tooth decay, and periodontal disease. But scientists have long hypothesized that probiotics might also boost cognition, as there is continuous two-way communication between the intestinal microflora, the gastrointestinal tract, and the brain through the nervous system, the immune system, and hormones (along the so-called "microbiota-gut-brain axis"). In mice, probiotics have indeed been shown to improve learning and memory, and reduce anxiety and depression- and OCD-like symptoms. But prior to the present study there was very limited evidence of any cognitive benefits in humans.
Here, the researchers, from Kashan University of Medical Sciences, Kashan, and Islamic Azad University, Tehran, Iran, present results from a randomized, double-blind, controlled clinical trial on a total of 52 women and men with Alzheimer's between 60 and 95 years of age. Half of the patients daily received 200 ml milk enriched with four probiotic bacteria Lactobacillus acidophilus, L. casei, L. fermentum, and Bifidobacterium bifidum (approximately 400 billion bacteria per species), while the other half received untreated milk.
At the beginning and the end of the 12-week experimental period, the scientists took blood samples for biochemical analyses and tested the cognitive function of the subjects with the MMSE questionnaire, which includes tasks like giving the current date, counting backwards from 100 by sevens, naming objects, repeating a phrase, and copying a picture.
Over the course of the study, the average score on the MMSE questionnaire significantly increased (from 8.7 to 10.6, out of a maximum of 30) in the group receiving probiotics, but not in the control group (from 8.5 to 8.0). Even though this increase is moderate, and all patients remained severely cognitively impaired, these results are important because they are the first to show that probiotics can improve human cognition. Future research, on more patients and over longer time-scales, is necessary to test if the beneficial effects of probiotics become stronger after longer treatment.
"In a previous study, we showed that probiotic treatment improves the impaired spatial learning and memory in diabetic rats, but this is the first time that probiotic supplementation has been shown to benefit cognition in cognitively impaired humans," says Professor Mahmoud Salami from Kashan University, the senior author of the study.
Treatment with probiotics also resulted in lower levels of triglycerides, Very Low Density Lipoprotein (VLDL), high-sensitivity C-Reactive Protein (hs-CRP) in the blood of the Alzheimer patients, and likewise a reduction in two common measures (called "Homeostatic Model Assessment," HOMA-IR and HOMA-B) of insulin resistance and the activity of the insulin-producing cells in the pancreas.
"These findings indicate that change in the metabolic adjustments might be a mechanism by which probiotics affect Alzheimer's and possibly other neurological disorders," says Salami. "We plan to look at these mechanisms in greater detail in our next study."
Walter Lukiw, Professor of Neurology, Neuroscience and Ophthalmology and Bollinger Professor of Alzheimer's disease at Louisiana State University, who reviewed the study but was not involved in the research, said: "This early study is interesting and important because it provides evidence for gastrointestinal (GI) tract microbiome components playing a role in neurological function, and indicates that probiotics can in principle improve human cognition. This is in line with some of our recent studies which indicate that the GI tract microbiome in Alzheimer's is significantly altered in composition when compared to age-matched controls, and that both the GI tract and blood-brain barriersbecome significantly more leaky with aging, thus allowing GI tract microbial exudates (e.g. amyloids, lipopolysaccharides, endotoxins and small non-coding RNAs) to access Central Nervous System compartments."
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/11/161110162840.htm
Children prenatally exposed to alcohol more likely to have academic difficulties
March 24, 2017
Science Daily/Research Society on Alcoholism
Despite greater awareness of the dangers of prenatal exposure to alcohol, the rates of Fetal Alcohol Spectrum Disorders remain alarmingly high. This study evaluated academic achievement among children known to be prenatally exposed to maternal heavy alcohol consumption as compared to their peers without such exposure, and explored the brain regions that may underlie academic performance.
Researchers assessed two groups of children, eight to 16 years of age: 67 children with heavy prenatal alcohol exposure (44 boys, 23 girls) and 61 children who were not prenatally exposed to alcohol (33 boys, 28 girls). Scores on standardized tests of academic areas such as reading, spelling, and math were analyzed. In addition, a subsample of 42 children (29 boys, 13 girls) had brain imaging, which allowed the authors to examine the relations between the cortical structure (thickness and surface area) of their brains and academic performance.
The alcohol-exposed children performed significantly worse than their peers in all academic areas, with particular weaknesses found in math performance. Brain imaging revealed several brain surface area clusters linked to math and spelling performance. The children without prenatal alcohol exposure demonstrated the expected developmental pattern of better scores associated with smaller brain surface areas, which may be related to a typical developmental process known as pruning. However, alcohol-exposed children did not show this pattern, possibly due to atypical or delayed brain development, which has been observed in other research studies. These results support previous findings of lower academic performance among children prenatally exposed to alcohol compared to their peers, which appear to be associated with differences in brain development, and highlight the need for additional attention and support for these children.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2017/03/170324192315.htm
Yoga may have health benefits for people with asthma
April 26, 2016
Science Daily/Wiley
A new review suggests that yoga may have a beneficial effect on symptoms and quality of life in people with asthma, but effects on lung function and medication use are uncertain.
Asthma is a common chronic disease affecting about 300 million people worldwide. The many typical symptoms of asthma include wheezing, coughing, chest tightness and shortness of breath.
Yoga has gained global popularity as a form of exercise with general life-style benefits, and recent studies have investigated the potential of yoga to relieve asthma-related problems.
A new Cochrane Review summarizes the results of randomised trials and has found evidence that practicing yoga might be able to improve asthma quality of life and symptoms to some extent. However, researchers also warned that higher-quality studies with more participants would be needed to draw any firm conclusions about the effects of yoga.
The team of Cochrane researchers wanted to find out the effects of yoga in people with asthma.
They found 15 randomised controlled trials which involved 1,048 men and women. Most of the trials were conducted in India, followed by Europe and the United States. The majority of participants had mild to moderate asthma for six months to more than 23 years. Six studies looked into the effects of breathing alone during yoga exercise, whilst the other studies assessed the effects of yoga that included breathing, posture and meditation.
Most people continued to take their usual asthma medication while participating in the studies. The studies were conducted over a time period of two weeks to over four years.
The researchers found some moderate quality evidence from five studies that yoga exercise reduces the impact of asthma on people's quality of life. However, evidence about yoga's impact on the participants' lung function is more uncertain because the results varied. The effects of yoga on medication use and any side-effects of yoga are also uncertain, because only a few very small studies reported these outcomes.
Lead author, Dr Zuyao Yang from the Jockey Club School of Public Health and Primary Care, at the Chinese University of Hong Kong commented, "Our findings suggest that yoga exercise may lead to small improvements in asthma quality of life and symptoms. However, it is unclear whether yoga has a consistent impact on lung function and we don't yet know if yoga can reduce people's medication usage, or if there are any side-effects of yoga for people with asthma."
Deputy Co-ordinating Editor of the Cochrane Airways Group, Rebecca Normansell, added, "At present, we just don't have enough high quality evidence to determine the effects of yoga as a type of exercise for helping people manage their asthma. Because there is uncertainty about the effects of yoga on lung function and use of asthma medication, it's important that people with asthma continue to take their medication, as prescribed. The findings of this Cochrane Review will help people make more informed choices about their future treatment options."
Science Daily/SOURCE : https://www.sciencedaily.com/releases/2016/04/160426215441.htm
Sense of purpose in life linked to lower mortality and cardiovascular risk
December 3, 2015
Science Daily/Wolters Kluwer Health: Lippincott Williams and Wilkins
People who have a higher sense of purpose in life are at lower risk of death and cardiovascular disease, reports a pooled data analysis.
https://images.sciencedaily.com/2015/12/151203112844_1_540x360.jpg
An analysis showed a lower risk of death for people with a high sense of purpose in life.
Credit: © alexbrylovhk / Fotolia
"Possessing a high sense of purpose in life is associated with a reduced risk for mortality and cardiovascular events," according to the study by Drs. Randy Cohen and Alan Rozanski and colleagues at Mt. Sinai St. Luke's-Roosevelt Hospital, New York. While the mechanisms behind the association remain unclear, the findings suggest that approaches to strengthening a sense of purpose might lead to improved health outcomes.
How Does Purpose in Life Affect Health and Mortality Risks?
Using a technique called meta-analysis, the researchers pooled data from previous studies evaluating the relationship between purpose in life and the risk of death or cardiovascular disease. The analysis included data on more than 136,000 participants from ten studies -- mainly from the United States or Japan. The US studies evaluated a sense of purpose or meaning in life, or "usefulness to others." The Japanese studies assessed the concept of ikigai, translated as "a life worth living."
The study participants, average age 67 years, were followed up for an average of seven years. During this time, more than 14,500 participants died from any cause while more than 4,000 suffered cardiovascular events (heart attack, stroke, etc).
The analysis showed a lower risk of death for participants with a high sense of purpose in life. After adjusting for other factors, mortality was about one-fifth lower for participants reporting a strong sense of purpose, or ikigai.
A high sense of purpose in life was also related to a lower risk of cardiovascular events. Both associations remained significant on analysis of various subgroups, including country, how purpose in life was measured, and whether the studies included participants with pre-existing cardiovascular disease..
There is a well-documented link between "negative psychosocial risk factors" and adverse health outcomes, including heart attack, stroke, and overall mortality. "Conversely, more recent study provides evidence that positive psychosocial factors can promote healthy physiological functioning and greater longevity," according to the authors.
The new analysis assembles high-quality data from studies assessing the relationship between purpose life and various measures of health and adverse clinical outcomes. The researchers write, "Together, these findings indicate a robust relationship between purpose in life and mortality and/or adverse cardiovascular outcomes."
While further studies are needed to determine how purpose in life might promote health and deter disease, preliminary data suggest a few basic mechanisms. The association might be explained physiologically, such as by buffering of bodily responses to stress; or behaviorally, such as by a healthier lifestyle.
"Of note, having a strong sense of life purpose has long been postulated to be an important dimension of life, providing people with a sense of vitality motivation and resilience," Dr. Rozanski comments. "Nevertheless, the medical implications of living with a high or low sense of life purpose have only recently caught the attention of investigators. The current findings are important because they may open up new potential interventions for helping people to promote their health and sense of well-being."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2015/12/151203112844.htm
Mentally challenging activities key to a healthy aging mind
Individuals who participated in high challenge activities like quilting and photography showed enhanced brain activity, according to a new Restorative Neurology and Neuroscience report
January 15, 2016
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/01/160115100906.htm
Science Daily/IOS Press
One of the greatest challenges associated with the growing numbers of aged adults is how to maintain a healthy aging mind. Taking up a new mental challenge such as digital photography or quilting may help maintain cognitive vitality, say researchers.
Recent evidence suggests that engaging in enjoyable and enriching lifestyle activities may be associated with maintaining cognitive vitality. However, the underlying mechanism accounting for cognitive enhancement effects have been poorly understood.
Investigators at the University of Texas at Dallas proposed that only tasks that involved sustained mental effort and challenge would facilitate cognitive function. Senior author Denise Park and lead author Ian McDonough compared changes in brain activity in 39 older adults that resulted from the performance of high-challenge activities that required new learning and sustained mental effort compared to low-challenge activities that did not require active learning. All of the participants underwent a battery of cognitive tests and brain scans using functional magnetic resonance imaging (fMRI), an MRI technology that measures brain activity by detecting changes associated with blood flow.
Participants were randomly assigned to the high-challenge, low-challenge, or placebo groups. The high-challenge group spent at least 15 hours per week for 14 weeks learning progressively more difficult skills in digital photography, quilting, or a combination of both. The low-challenge group met for 15 hours per week to socialize and engage in activities related to subjects such as travel and cooking with no active learning component. The placebo group engaged in low-demand cognitive tasks such as listening to music, playing simple games, or watching classic movies. All participants were tested before and after the 14-week period and a subset was retested a year later.
The high-challenge group demonstrated better memory performance after the intervention, and an increased ability to modulate brain activity more efficiently to challenging judgments of word meaning in the medial frontal, lateral temporal, and parietal cortex regions of the brain. These are brain areas associated with attention and semantic processing. Some of this enhanced brain activity was maintained a year later. This increased neural efficiency in judging words was demonstrated by participants showing lowered brain activity when word judgments were easy and increasing activity when they became hard. This is a pattern of response typical of young adults. Before participating in the high-challenge intervention, the older adults were processing every item, both easy and hard, with maximum brain activity. After participation, they were able to modulate their brain activity to the demands of the task, thus showing a more efficient use of neural resources. This change in modulation was not observed in the low-challenge group.
The findings show that mentally demanding activities may be neuroprotective and an important element for maintaining a healthy brain into late adulthood.
"The present findings provide some of the first experimental evidence that mentally-challenging leisure activities can actually change brain function and that it is possible that such interventions can restore levels of brain activity to a more youth-like state. However, we would like to conduct much larger studies to determine the universality of this effect and understand who will benefit the most from such an intervention," explained senior author Denise C. Park, PhD, of the Center for Vital Longevity, School of Behavioral and Brain Sciences, University of Texas at Dallas.
Ian McDonough, who is now an assistant professor of Psychology at the University of Alabama and was first author on the study, said: "The study clearly illustrates that the enhanced neural efficiency was a direct consequence of participation in a demanding learning environment. The findings superficially confirm the familiar adage regarding cognitive aging of 'Use it or lose it.'"
Denise Park added, "Although there is much more to be learned, we are cautiously optimistic that age-related cognitive declines can be slowed or even partially restored if individuals are exposed to sustained, mentally challenging experiences."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/01/160115100906.htm
Health goes downhill when older adults stop driving
Study shows seniors experience double the risk of depressive symptoms, along with declines in cognition and physical functioning
January 25, 2016
Science Daily/Columbia University's Mailman School of Public Health
While 81 percent of the 29.5 million older U.S. adults continue to hold a license and get behind the wheel, age-related declines in cognition and physical function make driving more difficult, and many seniors eventually stop driving altogether. Researchers examined the health of older adults after they stopped driving and found that driving cessation nearly doubled the risk of depressive symptoms, while also contributing to diminished cognitive abilities and physical functioning.
"For many older adults, driving is more than a privilege; it is instrumental to their daily living and is a strong indicator of self-control, personal freedom, and independence," said Guohua Li, MD, DrPH, Mailman School professor of Epidemiology, the founding director of the Center for Injury Epidemiology and Prevention at Columbia, and senior author. "Unfortunately, it is almost inevitable to face the decision to stop driving during the process of aging as cognitive and physical functions continue to decline."
Dr. Li and a team of researchers reviewed and analyzed quantitative health-related data for drivers aged 55 and older from 16 studies that met eligibility criteria and compared results with data from current drivers. The study updates and expands on earlier findings with more than 10 additional years of empirical research.
Data showed that older adults experienced faster declines in cognitive function and physical health after stopping driving. Driving cessation was also associated with a 51-percent reduction in the size of social networks of friends and relatives--something the researchers say can contrain the social lives of seniors and their ability to engage with others. Decline in social health after driving cessation appeared greater in women than in men.
Former drivers were also nearly five times as likely as current drivers to be admitted to a nursing home, assisted living community, or retirement home, after adjusting for marital status or co-residence.
"As older ex-drivers begin substituting outside activities with indoor activities around the home, these activities may not be as beneficial to physical functioning as working or volunteering on the outside," said Thelma Mielenz, PhD, assistant professor of Epidemiology at the Mailman School and co-author. "When time comes to stop driving, it is important to make personalized plans to maintain mobility and social functions."
The researchers note that merely making alternative transportation available to older adults does not necessarily offset the adverse health effects of driving cessation. "What we need most of all are effective programs that can ensure and prolong an older adult's mobility, physical, and social functioning," said Li.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/01/160125184502.htm
For older adults, serious depression symptoms increase risk for stroke and heart disease
February 1, 2016
Science Daily/American Geriatrics Society
Adults 65-years-old and older who had high levels of depressive symptoms had a greater risk for experiencing heart disease or stroke events over the 10 years of a study, scientists report. As a result, the researchers concluded that depression could be a risk factor for heart disease or stroke.
Depression and its symptoms increase as people age, and have been linked to heart disease and stroke in both middle-aged and older adults. But whether depression and its symptoms are risk factors for these two dangerous conditions has been unclear.
In a new study published in the Journal of the American Geriatrics Society, researchers set out to learn more about whether depression or its symptoms affect heart disease and stroke in older adults.
The researchers studied 7,313 older adults selected from the election rolls of three large French cities between 1999 and 2001. None of the participants had a history of heart disease, stroke, or dementia at the start of the study. Researchers conducted face-to-face interviews with the participants when the study began, and checked them again three times--two years, four years, and seven years after their initial interview. In addition, researchers tested the participants' mental health status, blood sugar, and cholesterol levels, and asked them questions about medical history and medications. In addition, the researchers determined whether or not the participants had symptoms of depression.
At the beginning of the study, nearly 30 percent of the women and 15 percent of the men (23 percent of all participants in total) had high levels of depressive symptoms. The researchers discovered that about 40 percent of people with high levels of depressive symptoms "recovered" and the same amount of people developed new depression symptoms at each follow-up visit. During all study visits, fewer than 10 percent of the participants were taking medications for depression.
The researchers discovered that adults 65-years-old and older who had high levels of depressive symptoms on one, two, three, or four occasions during the study had 15 percent, 32 percent, 52 percent, and 75 percent greater risk, respectively, for experiencing heart disease or stroke events over the 10 years of the study. As a result, the researchers concluded that depression could be a risk factor for heart disease or stroke. They suggested that physicians pay close attention to symptoms of depression in older adults under care.
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2016/02/160201141733.htm
Membership of social/community groups after retirement linked to longer life
Health and wellbeing benefits equal to those of regular exercise
February 15, 2016
Science Daily/BMJ
Membership of social groups, such as book clubs or church groups, after retirement is linked to a longer life, with the impact on health and wellbeing similar to that of regular exercise, suggests new research.
The more groups an individual belongs to in the first few years after s/he stops working, the lower their risk of death, the findings show.
Retirement represents a major life change, with the evidence from large long-term studies suggesting that the health and wellbeing of a substantial number of retirees goes downhill after they stop formal work.
But some people adjust to this transition better than others. In a bid to assess the potential impact of social group memberships, the researchers tracked the health of 424 people for six years after they had retired.
They were compared with the same number of people, matched for age, sex, and health status, but who were still working.
All the participants were at least 50 years old, living in England, and taking part in the English Longitudinal Study of Ageing, which started in 2002-3.
Each participant was asked how many different organisations, clubs, or societies, s/he belonged to, and which ones. They were also asked to complete a validated scale to assess quality of life, and another, to assess subjective physical health.
The results showed that individuals whose quality of life was good before retirement were more likely to score highly on quality of life assessment after retirement.
But membership of social groups was also associated with quality of life. Compared with those still working, every group membership lost after retirement was associated with around a 10% drop in quality of life score six years later.
Some 28 (6.65%) of the retirees died in the first six years after stopping work. Unsurprisingly, the strongest predictor of death was age, with someone at the age of 55 running a 1% risk of dying compared with an 8% chance for someone aged 65.
Subjectively rated health was not a significant predictor of death, but the number of group memberships was.
If a person belonged to two groups before retirement, and kept these up over the following six years, their risk of death was 2%, rising to 5% if they gave up membership of one, and to 12% if they gave up membership of both.
No such patterns were seen for those still in formal employment.
The researchers separately assessed whether changes in physical activity levels affected risk of death and compared this with the magnitude of the effect of social group membership.
They found that if a person exercised vigorously once a week before retirement, and kept up this frequency afterwards, their chance of dying over the next six years was 3%, rising to 6% if they reduced the frequency to less than once a week, and to 11% if they stopped altogether.
Among those who were still working, the equivalent figures were 3%, 5%, and 8%.
"Accordingly, we can see that the effects of physical activity on health were comparable to those associated with maintaining old group memberships and developing new ones," write the researchers.
This is an observational study so no firm conclusions can be drawn about cause and effect, but the findings have unique practical implications for retirement planning, say the researchers.
"They suggest that as much as practitioners may help retirees adjust by providing support with financial planning, they may also help by providing social planning," they write.
"In this regard, practical interventions should focus on helping retirees to maintain their sense of purpose and belonging by assisting them to connect to groups and communities that are meaningful to them," they conclude.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/02/160215210701.htm
Older adults have their own perspectives on sadness, loneliness and serenity
February 25, 2016
Science Daily/University of Massachusetts at Amherst
Older adults have different, more positive responses than young adults about feelings such as serenity, sadness and loneliness, a new study shows. An author calls the findings 'highly clinically significant' because the information could help caregivers, psychotherapists and workers at assisted living facilities better understand the emotions of older people in their care.
Ready calls the findings "highly clinically significant" because the information could help caregivers, psychotherapists and workers at assisted living facilities, for example, better understand the emotions of older people in their care, which could lead to improved treatment and quality of interactions. Findings appear in the current online issue of Aging and Mental Health.
She says, "Older adults report feeling more serenity than younger persons. They also have a richer concept of what it means to feel serene than younger persons." In a word grouping task, older adults associated more positive emotional terms with serene, such as cheerful, happy and joyful, than did younger people. The authors speculate that "this broader conception of serene" is associated with the fact that older adults report more calming positive emotions than younger people.
She adds, "We were surprised to find that younger adults associated more self-deprecating terms with feeling sad and lonely, such as being ashamed or disgusted with themselves, than older persons." When grouping other emotion words with sadness, older adults included words such as droopy and sheepish, while younger adults included more self-deprecating terms with the word, such as dissatisfied with self, ashamed, angry and disgusted with self. A similar pattern was observed for lonely.
For this study, Ready and her graduate student Gennarina Santorelli recruited 32 older adults ages 60 to 92, and 111 younger adults ages 18 to 32, and asked them to judge 70 emotion terms on whether the words had a positive or negative connotation and if the words were activating or arousing. For example, excited is generally rated as a high activation word, while serene is associated with less activation. They then had participants group similar words together.
Ready and colleagues found the word groupings were similar between older and younger persons for many words but they noted systematic differences for sadness, loneliness and, as noted above, serenity. They also found that older adults perceive emotion terms as most positive and more active than younger persons. Emotions overall may be more stimulating for older than younger persons.
The older adults in this study reported fewer depressive symptoms than the younger participants. Controlling for age group differences in these symptoms, Ready says, "We gained a deeper appreciation of some relatively unknown benefits of aging, such as increased positive emotions and less shame associated with feeling sad or lonely."
As the percentage of older adults in the United States increases, Ready says, "It is imperative to determine how older adults define emotions differently than younger adults. These data ensure effective communication with older adults, accurate understanding of their emotion experiences, and appropriate access to psychological interventions."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/02/160225140042.htm
Exercise may slow brain aging by 10 years for older people
March 23, 2016
Science Daily/American Academy of Neurology
Exercise in older people is associated with a slower rate of decline in thinking skills that occurs with aging. People who reported light to no exercise experienced a decline equal to 10 more years of aging as compared to people who reported moderate to intense exercise, according to a population-based observational study.
"The number of people over the age of 65 in the United States is on the rise, meaning the public health burden of thinking and memory problems will likely grow," said study author Clinton B. Wright, MD, MS, of the University of Miami in Miami, Fla., and member of the American Academy of Neurology. "Our study showed that for older people, getting regular exercise may be protective, helping them keep their cognitive abilities longer."
For the study, researchers looked at data on 876 people enrolled in the Northern Manhattan Study who were asked how long and how often they exercised during the two weeks prior to that date. An average of seven years later, each person was given tests of memory and thinking skills and a brain MRI, and five years after that they took the memory and thinking tests again.
Of the group, 90 percent reported light exercise or no exercise. Light exercise could include activities such as walking and yoga. They were placed in the low activity group. The remaining 10 percent reported moderate to high intensity exercise, which could include activities such as running, aerobics, or calisthenics. They were placed in the high activity group.
When looking at people who had no signs of memory and thinking problems at the start of the study, researchers found that those reporting low activity levels showed a greater decline over five years compared to those with high activity levels on tests of how fast they could perform simple tasks and how many words they could remember from a list. The difference was equal to that of 10 years of aging. The difference also remained after researchers adjusted for other factors that could affect brain health, such as smoking, alcohol use, high blood pressure and body mass index.
"Physical activity is an attractive option to reduce the burden of cognitive impairment in public health because it is low cost and doesn't interfere with medications," said Wright. "Our results suggest that moderate to intense exercise may help older people delay aging of the brain, but more research from randomized clinical trials comparing exercise programs to more sedentary activity is needed to confirm these results."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/03/160323185527.htm
Depression symptoms that steadily increase in later life predict higher dementia risk
April 29, 2016
Science Daily/The Lancet
Depression symptoms that steadily increase in older adults are more strongly linked to dementia than any other types of depression, and may indicate the early stages of the disease, according to the first ever long-term study to examine the link between dementia and the course of depression.
Symptoms of depression are common in people with dementia, but previous studies have often looked at single episodes of depression, failing to take into account how depression develops over time. The course of depression varies greatly between individuals -- some might experience depressive symptoms only transiently, followed by full remission, others might have remitting and relapsing depression, and some might be chronically depressed. Different courses of depression may reflect different underlying causes, and might be linked to different risks of dementia.
The study included 3325 adults aged 55 and over, who all had symptoms of depression but no symptoms of dementia at the start of the study. The data was gathered from the Rotterdam Study, a population-based cohort study of various diseases in the Netherlands which allowed the authors to track depressive symptoms over 11 years and the risk of dementia for a subsequent 10 years.
Using the Center for Epidemiology Depression Scale (CES-D) and the Hospital Anxiety and Depression Scale-Depression (HADS-D), the authors identified five different trajectories of depressive symptoms -- low depression symptoms (2441 participants); initially high symptoms that decreased (369); low starting scores that increased then remitted (170); initially low symptoms that increased (255); and constantly high symptoms (90).
Of the 3325 participants, 434 developed dementia, including 348 cases of Alzheimer's disease. Among the group with low symptoms of depression, 10% (226/2174) developed dementia. The researchers used this as the benchmark against which to compare other trajectories of depression -- the study did not compare the risk of dementia following depression with the risk of dementia for adults in the general population (without depression).
Only the group whose symptoms of depression increased over time was at an increased risk of dementia- 22% of people (55/255) in this group developed dementia. This risk was particularly pronounced after the first 3 years. Individuals with remitting symptoms of depression were not at an increased risk of dementia compared to individuals with low depressive symptoms. The authors say that this suggests that having severe symptoms of depression at one point in time does not necessarily have any lasting influence on the risk of dementia.
The authors say their findings support the hypothesis that increasing symptoms of depression in older age could potentially represent an early stage of dementia. They also say that the findings support previous suggestions that dementia and some forms of depression may be symptoms of a common cause. They say that at the molecular levels, the biological mechanisms of depression and neurodegenerative diseases overlap considerably including the loss of ability to create new neurons, increased cell death and immune system dysregulation.
According to Dr M Arfan Ikram, Department of Epidemiology, Erasmus University Medical Center, Rotterdam, Netherlands, "Depressive symptoms that gradually increase over time appear to better predict dementia later in life than other trajectories of depressive symptoms such as high and remitting, in this study. There are a number of potential explanations, including that depression and dementia may both be symptoms of a common underlying cause, or that increasing depressive symptoms are on the starting end of a dementia continuum in older adults. More research is needed to examine this association, and to investigate the potential to use ongoing assessments of depressive symptoms to identify older adults at increased risk of dementia."
Writing in a linked Comment, Dr Simone Reppermund from the Department of Developmental Disability and Centre for Healthy Brain Ageing at the University of New South Wales, Sydney, Australia, says: "In conclusion, several factors can contribute to the development of both depression and dementia. The questions are if, and how, the presence of depression modifies the risk for dementia. The study by Mirza and colleagues provides an answer to the first question: depression, especially steadily increasing depressive symptoms, seems to increase the risk for dementia. However, the question of how the presence of depressive symptoms modifies the risk of dementia still remains. More studies of depression trajectories over a long period, with inclusion of biological measures, are necessary to understand the link between depression and dementia, in particular the underlying mechanisms. A focus on lifestyle factors such as physical activity and social networks, and biological risk factors such as vascular disease, neuroinflammation, high concentrations of stress hormones, and neuropathological changes, might bring new treatment and prevention strategies a step closer."
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/04/160429192926.htm
Among the oldest adults, poor balance may signal higher risk for dementia
July 25, 2016
Science Daily/American Geriatrics Society
In a first-of-its-kind study, researchers examined whether four different measures of poor physical performance might be linked to increased dementia risk for people aged 90 and older.
The number of people living well into their 90s is projected to quadruple by 2050. By mid-century, nearly 9 million people will be 90-years-old or older. In a first-of-its-kind study published in the Journal of the American Geriatrics Society, researchers from the University of California at Irvine examined whether four different measures of poor physical performance might be linked to increased dementia risk for people aged 90 and older.
Previous studies have shown that poor physical performance is linked to increased odds for dementia in people younger than 85. But until now, we didn't know whether a link between poor physical performance and dementia existed for people 90 and older.
The researchers examined 578 people aged 90 and older who were participants in The 90+ Study, a community-based longitudinal study -- a research method that follows the same subjects repeatedly over a period of time -- of the oldest-old in Southern California. Examiners see the participants every six months to conduct physical and neurological (the branch of medicine dealing with the study of nerves and the nervous system) examinations as well as cognitive tests, with the goal of looking critically at aging and dementia specifically.
At the start of the study, about 50 percent of the participants were cognitively impaired (had trouble thinking or remembering), but did not have dementia. The rest were cognitively normal. Researchers followed the participants for 2.6 years and, during that time, almost 40 percent of participants developed dementia.
The researchers observed a unique link between dementia risk and poor performance on two different physical performance tests: the standing balance test and the four-meter (about 13 feet) walking test.
The researchers suggested that, since walking and standing balance require complex brain activity, testing these functions may help doctors predict who among the "oldest-old" might be most at risk for developing dementia. The researchers also note that future studies could lead to the development of prevention programs and treatment strategies.
Science Daily/SOURCE :https://www.sciencedaily.com/releases/2016/07/160725151154.htm