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Another study finding a link between air pollution and negative health effects - this time a higher incidence of decline in cognitive functioning  and dementia in older women (65 and older) exposed to fine particles (PM2.5 ). These extremely small particles from vehicle emissions are a major source of urban air pollution throughout the world. These results match other studies finding a link with urban air pollution, especially vehicle traffic, to negative effects on the brain (dementia, cognitive decline, shrinking of the brain, etc.). The researchers also exposed mice to this air pollution for 15 weeks and then studied their brains for evidence of degenerative effects in their brains - and yes, they did find them.

The researchers found that the adverse effects of fine particulate air pollution was stronger in both women and mice who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's disease. They said that while the air pollution has negative effects in general, that having the APOE4 gene interacted with the air pollution. The researchers also wrote that the mice studies they did showed that "...exposure to urban airborne particulates can intensify amyloid accumulation and neurodegeneration". Medical Xpress:

Air pollution may lead to dementia in older women

Tiny air pollution particles—the type that mainly comes from power plants and automobiles—may greatly increase the chance of dementia, including Alzheimer's disease, according to USC-led research. Scientists and engineers found that older women who live in places with fine particulate matter exceeding the U.S. Environmental Protection Agency's standard are 81 percent more at risk for global cognitive decline and 92 percent more likely to develop dementia, including Alzheimer's.

If their findings hold up in the general population, air pollution could be responsible for about 21 percent of dementia cases, according to the study. "Microscopic particles generated by fossil fuels get into our body directly through the nose into the brain," said University Professor Caleb Finch at the USC Leonard Davis School of Gerontology and co-senior author of the study. "Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time, appear to exacerbate and promote Alzheimer's disease.

The adverse effects were stronger in women who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's. "Our study .....provides the inaugural scientific evidence of a critical Alzheimer's risk gene possibly interacting with air particles to accelerate brain aging," said Jiu-Chiuan Chen, co-senior author of the study....[Their study] adds to an emerging body of research from around the world that links air pollution to dementia. The offending pollutants—known as PM2.5—are fine, inhalable particles with diameters 2.5 micrometers or smaller. A human hair is about 70 micrometers in diameter, making it 30 times larger than the largest PM2.5. The researchers analyzed data of 3,647 65- to 79-year-old women from the Women's Health Initiative Memory Study (WHIMS). These women lived across 48 states and did not have dementia when they enrolled.

USC scientists chronically exposed female mice carrying the APOE4 gene to nano-sized air pollution for 15 weeks. Compared to the control group, mice predisposed to Alzheimer's disease accumulated as much as 60 percent more amyloid plaque, the toxic clusters of protein fragments that further the progression of Alzheimer's.

In other studies, Chen and his colleagues linked long-term exposure to high PM2.5 levels to smaller gray and white matter volumes in important areas such as the frontal lobe, which carries out thinking, decision-making and planning. For every 3.5 micrograms of PM2.5 per cubic meter of air, white matter (insulated nerve fibers that connect different brain regions) decreased by 6 cubic centimeters, according to one earlier study. [see post]

  Eating lots of fruits and vegetables (more than 10 servings a day!)  is linked to better cognitive functioning in both normal weight and overweight adults (both young and older adults), and may delay the onset of cognitive decline that occurs with aging and also dementia. Overweight and obese older adults with a daily fruit and vegetable consumption of less than 5 servings generally had worse cognitive functioning. Higher levels of physical activity and higher daily fruit and vegetable consumption were both associated with better cognitive functioning. Cognitive functioning generally refers to a person’s ability to reason and think, the mental processes needed to gather and process information, and all aspects of language and memory.

The York University researchers found that fruit and vegetable consumptionphysical activity, and BMI or body mass index (normal, overweight, obese) all appear to interact in how a person mentally functions (cognitive functioning), especially as they age. The ideal goal as one ages is to preserve the mind. It appears that eating lots of fruits and vegetables daily (10 or more servings), being physically active (this includes daily walks), and being a healthy weight help with this goal. It helps to also be highly educated (or read books?) so that the brain has a "cognitive reserve",

Why is daily fruit and vegetable consumption (FVC) good for cognitive functioning and the brain? Studies find that daily consumption of fruits and vegetables is strongly associated with a reduced risk of cardiovascular disease, cancer, diabetes and age-related declines. They appear to be "protective" against cognitive decline. The study researchers point out that fruits and vegetables contain high quantities of vitamin C and E, fiber, micronutrients, flavonoids, beta-carotenes and other classes of phytochemicals. These are important in various ways: "they modulate detoxifying enzymes, stimulate the immune system, modulate cholesterol synthesis, and act as antibacterial, antioxidant or neuroprotective agents." NOTE: A serving of fruit is generally 1 medium fruit or 1/2 cup of fruit. A serving of vegetables is 1 cup of raw leafy greens or 1/2 cup of other vegetables. From Medical Xpress:

Healthy living linked to higher brain function, delay of dementia

It's tempting to dip into the leftover Halloween treats, but new research out of York University has found eating plenty of fruits and vegetables, combined with regular exercise, leads to better cognitive functioning for younger and older adults, and may delay the onset of dementia. York U post-doctoral fellow Alina Cohen and her team, including Professors Chris I. Ardern and Joseph Baker, looked at cross-sectional data of 45,522 participants, age 30 to 80+, from the 2012 annual component of the Canadian Community Health Survey.

What they found was that for those who are normal weight or overweight, but not obese, eating more than 10 servings of fruit and vegetable daily was linked to better cognitive functioning. When moderate exercise was added, those eating less than five servings, reported better cognitive functioning. Higher levels of physical activity were linked to the relationship between higher daily fruit and vegetable consumption and better cognitive performance. Those with higher body mass indexes, low activity levels and fruit and vegetable consumption were associated with poorer cognitive functioning.

More details from the original study in the Journal of Public Health: Physical activity mediates the relationship between fruit and vegetable consumption and cognitive functioning: a cross-sectional analysis

Results: Higher BMIs, lower PA [physical activity] and FVC [fruit and vegetable consumption] were associated with poorer cognitive functioning. Additionally, PA statistically mediated the relationship between FVC and cognitive function (Sobel test: t = −3.15; P < 0.002); and higher education levels and daily FVC were associated with better cognitive function (P < 0.001). Conclusion: Higher PA levels were associated with better cognitive functioning in younger and older adults. Also, higher daily FVC and education levels were associated with better cognitive scores.

Individuals who were normal weight or overweight and reported a FVC of >10 servings per day reported better cognitive functioning scores than those who reported <10 servings, as well as those individuals with obesity . As well, both active and inactive individuals who reported a FVC of >10 servings per day had better cognitive scores than those who consumed fewer servings. However, in those who were moderately active, individuals with a daily FVC of <5 or 5–10 servings reported better cognitive functioning than those with a daily FVC of 10 or more servings; this may have resulted because of underestimations of the number of servings of fruits and vegetables actually consumed... Thus, increasing FVC and PA levels as well as having a healthy BMI may aid in the delay of cognitive decline.

Results also indicated that higher education levels along with a daily FVC of five or more servings were associated with better cognitive functioning. Education may be assisting in the process of delaying cognitive decline by increasing cognitive reserve, the ability of the human brain to cope with damage by using different brain processes to retain the ability to function well. Cognitive reserve is developed through intellectual stimulation and translates into a higher volume of connections between neurons and stronger rates of cerebral blood flow.

A new study conducted in China found an association between low vitamin D levels and future cognitive decline in older adults. The lower the vitamin D levels at the initial screening (the baseline), the more people with cognitive decline at a 2 year follow-up. There were were no gender differences. (Another study with similar results.) Vitamin D is produced naturally in the skin when exposed to sunlight, and also found in smaller amounts in food such as fish (e.g. salmon) and eggs. Vitamin D helps maintain healthy bones and muscles, but it also plays a key part in brain function and is viewed as neuroprotective. Low levels are associated with greater risk of cardiovascular and neurodegenerative diseases.

The 1,202 participants (60 years or older) in China had their baseline vitamin D levels measured at the start of the study, and their cognitive abilities assessed over two years. What I found interesting in this study was that the vitamin D levels in the people was in general pretty low - this was without any supplementation, thus from sunlight. The researchers specified vitamin D levels (25-Cholecalciferol) in nmol/l, but in the United States values are generally specified in ng/ml. In the study the median level of vitamin D levels in the lowest quartile converted to ng/ml was 10.0 ng/ml, and in the highest quartile the median level was 26.4 ng/ml. With those low numbers, all 4 groups in the United States would be advised to supplement daily with vitamin D (specifically vitamin D3). From Journals of Gerontology: Medical Sciences:

Vitamin D Levels and the Risk of Cognitive Decline in Chinese Elderly People: the Chinese Longitudinal Healthy Longevity Survey

Vitamin D has a neuroprotective function, potentially important for the prevention of cognitive decline. Prospective studies from Western countries support an association between lower vitamin D level and future cognitive decline in elderly people.

This community-based cohort study of elderly people in China follows 1,202 cognitively intact adults aged ≥60 years for a mean duration of 2 years. Plasma vitamin D level was measured at the baseline. Cognitive state of participants was assessed using the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as an MMSE score <18. Cognitive decline was defined as ≥3 points decline from baseline....Participants with low vitamin D level had an increased risk of cognitive decline. This first follow-up study of elderly people, including the oldest-old, in Asia shows that low vitamin D levels were associated with increased risk of subsequent cognitive decline and impairment.

Vitamin D is a secosteroid hormone necessary for maintaining good musculoskeletal health; its deficiency is associated with increased risks of cardiovascular and neurodegenerative diseases. Vitamin D is primarily synthesized in the skin upon exposure to sunlight; smaller amounts are obtained through dietary intake. More recently, enzymes responsible for the synthesis of its active form have been found to be distributed throughout the human brain.... This growing body of evidence suggests that vitamin D has a neuroprotective function that is potentially important for the prevention of cognitive decline. Although the importance of vitamin D cannot be disregarded, there is still no consensus on its optimal level. This is especially pertinent in the elderly people, the oldest-old in particular, as cutaneous synthesis of vitamin D decreases with age. Moreover, their impaired mobility and limited outdoor activities can further exacerbate vitamin D deficiency.

Cross-sectional studies have generally found a positive association between vitamin D status and cognitive performance in older adults. Recent prospective studies from United States and Europe support an association between diminished vitamin D status and future cognitive decline. Since cutaneous synthesis is the main source of vitamin D, there exists great variability in vitamin D levels across populations due to differences in latitude, seasons, and race/ethnicity, such as level of skin pigmentation.

Our findings were consistent with previous cohort studies showing that vitamin D status predicts cognitive decline....A notable observation in the present study is that the association of vitamin D status and cognitive decline were similar in both oldest-old and less elderly people. In this study, there was a clear association between lower 25(OH)D3 level and cognitive impairment in subjects aged ≥80....An additional difference from previous studies is that the current study indicates that the association between vitamin D and cognitive impairment is not gender specific.

The observation of temporal association between 25(OH)D3 levels and subsequent cognitive function supports the notion that vitamin D has a clinically important neuroprotective effect. A wide variety of mechanisms for this effect has been proposed and is supported by animal studies. Vitamin D has been found to modulate neuronal calcium homeostasis, cerebral process of detoxification, immunomodulation, and beta-amyloid clearance.....Further, it was unlikely that vitamin D supplementation would explain the association in this study, as 87% of the participants reported no use of vitamin supplements....In conclusion, our longitudinal study indicates that low 25(OH) D3 levels are associated with subsequent cognitive decline and cognitive impairment

Another study showing that higher physical activity (from a variety of activities) is "related to larger gray matter volume in the elderly, regardless of cognitive status", specifically in gray matter areas of the brain responsible for memory, learning, and cognition. In other words, higher levels of physical activity reduce brain atrophy that occurs with aging and improves cognitive function in elderly individuals.  There is also discussion of higher activity levels improving cerebral (brain) blood flow. Bottom line: get off your butt and move more for better brain health. From Medical Xpress:

Burning more calories linked with greater gray matter volume, reduced Alzheimer's risk

Whether they jog, swim, garden or dance, physically active older persons have larger gray matter volume in key brain areas responsible for memory and cognition, according to a new study by researchers at the University of Pittsburgh School of Medicine and UCLA.The findings, published today in the Journal of Alzheimer's Disease, showed also that people who had Alzheimer's disease or mild cognitive impairment experienced less gray matter volume reduction over time if their exercise-associated calorie burn was high.

A growing number of studies indicate physical activity can help protect the brain from cognitive decline, said investigator James T. Becker, Ph.D., professor of psychiatry, Pitt School of Medicine..... "Our study is one of the largest to examine the relationship between physical activity and cognitive decline, and the results strongly support the notion that staying active maintains brain health."

Led by Cyrus Raji, M.D., Ph.D., formerly a student at Pitt School of Medicine and now a senior radiology resident at UCLA, the team examined data obtained over five years from nearly 876 people 65 or older participating in the multicenter Cardiovascular Health Study. All participants had brain scans and periodic cognitive assessments. They also were surveyed about how frequently they engaged in physical activities, such as walking, tennis, dancing and golfing, to assess their calorie expenditure or energy output per week.

Using mathematical modeling, the researchers found that the individuals who burned the most calories had larger gray matter volumes in the frontal, temporal and parietal lobes of the brain, areas that are associated with memory, learning and performing complex cognitive tasks. In a subset of more than 300 participants at the Pitt site, those with the highest energy expenditure had larger gray matter volumes in key areas on initial brain scans and were half as likely to have developed Alzheimer's disease five years later.

"Gray matter houses all of the neurons in your brain, so its volume can reflect neuronal health," Dr. Raji explained. "We also noted that these volumes increased if people became more active over five years leading up to their brain MRI."

New research has found that low vitamin D levels among older adults is associated with accelerated cognitive decline and impaired performance (particularly in areas of memory and executive function). The next research in this area will have to look at whether vitamin D supplementation will change (slow down) the decline. Please note that it is widely accepted that an average daily intake of 1000 IU  of D3 daily is safe. The best source of  vitamin D is sunlight. From Science Daily:

Low vitamin D among elderly associated with decline in cognition, dementia

Vitamin D insufficiency among the elderly is highly correlated with accelerated cognitive decline and impaired performance, particularly in domains such as memory loss that are associated with Alzheimer's disease and dementia, researchers with the UC Davis Alzheimer's Disease Center and Rutgers University have found. The effect is "substantial," with individuals with low vitamin D declining at a rate three times faster than those with adequate vitamin D levels

The researchers said their findings amplify the importance of identifying vitamin D insufficiency among the elderly, particularly high-risk groups such as African-Americans and Hispanics, who are less able to absorb the nutrient from its most plentiful source: sunshine. Among those groups and other darker-skinned individuals, low vitamin D should be considered a risk factor for dementia, they said. "Independent of race or ethnicity, baseline cognitive abilities and a host of other risk factors, vitamin D insufficiency was associated with significantly faster declines in both episodic memory and executive function performance," said Joshua Miller...

The large, longitudinal study was conducted in nearly 400 racially and ethnically diverse men and women in Northern California participating in longitudinal research at the Alzheimer's Disease Center in Sacramento, Calif. Fifty percent of participants were Caucasian and 50 percent were African-American or Hispanic. The participants had a mean age of 76 and were either cognitively normal, had mild cognitive impairment, or dementia.The participants' serum vitamin D status was measured at the beginning of the study.... Overall, 26 percent were deficient and 35 percent were insufficient. Among Caucasians, 54 percent had low vitamin D, compared with 70 percent of African-Americans and Hispanics.

Over five years of follow-up, vitamin D deficient individuals experienced cognitive declines that were two-to-three times faster than those with adequate serum vitamin D levels. In other words it took only two years for the deficient individuals to decline as much as their counterparts with adequate Vitamin D declined during the five-year follow-up period.

Exposing the skin to sunlight is the major source of vitamin D. Racial and some ethnic minorities are at greater risk of low vitamin D because the higher concentration of melanin that makes their skin darker -- and protects against skin cancer in sunny climates -- also inhibits synthesis of vitamin D. Diet is the other major source of vitamin D. Dietary vitamin D is obtained particularly through dairy consumption. The intake of dairy products is especially low among minority groups, with only 6.5 percent of African-Americans and 11 percent of Mexican-Americans nationwide consuming the recommended three daily servings of dairy products, the study says.

Once again, a study finds that a supplement has no benefit - here omega-3 supplements did not slow cognitive decline in older adults. On the other hand, studies find that eating foods with omega-3 fatty acids (such as fish) has beneficial health effects. Regular consumption of fish is associated with lower rates of age-related macular degeneration (AMD), cardiovascular disease, and possibly dementia.  From Science Daily:

No benefit of omega-3 supplements for cognitive decline, study shows

While some research suggests that a diet high in omega-3 fatty acids can protect brain health, a large clinical trial by researchers at the National Institutes of Health found that omega-3 supplements did not slow cognitive decline in older persons. With 4,000 patients followed over a five-year period, the study is one of the largest and longest of its kind.

Dr. Chew leads the Age-Related Eye Disease Study (AREDS), which was designed to investigate a combination of nutritional supplements for slowing age-related macular degeneration (AMD), a major cause of vision loss among older Americans. That study established that daily high doses of certain antioxidants and minerals -- called the AREDS formulation -- can help slow the progression to advanced AMD.

A later study, called AREDS2, tested the addition of omega-3 fatty acids to the AREDS formula. But the omega-3's made no difference. Omega-3 fatty acids are made by marine algae and are concentrated in fish oils; they are believed to be responsible for the health benefits associated with regularly eating fish, such as salmon, tuna, and halibut.* Where studies have surveyed people on their dietary habits and health, they've found that regular consumption of fish is associated with lower rates of AMD, cardiovascular disease, and possibly dementia. "We've seen data that eating foods with omega-3 may have a benefit for eye, brain, and heart health," Dr. Chew explained.

Omega-3 supplements are available over the counter and often labeled as supporting brain health. A large 2011 study found that omega-3 supplements did not improve the brain health of older patients with preexisting heart disease.

With AREDS2, Dr. Chew and her team saw another opportunity to investigate the possible cognitive benefits of omega-3 supplements, she said. All participants had early or intermediate AMD. They were 72 years old on average and 58 percent were female....Participants were given cognitive function tests at the beginning of the study to establish a baseline, then at two and four years later.... The cognition scores of each subgroup decreased to a similar extent over time, indicating that no combination of nutritional supplements made a difference.

* Other omega-3 fatty acids are found in plant foods such as flaxseed, walnuts, soy products, and canola and soybean oils. Specific omega-3 fatty acids from these sources were not studied.

Another study finds health benefits to eating a Mediterranean based diet (here combined with the DASH diet) - the MIND diet. The researchers found that the older adults who followed the diet best were about 7.5 years younger cognitively than those who followed it least, thus suggesting that it may slow the cognitive decline of aging. Earlier research had suggested that it may reduce a person's risk in developing Alzheimer's disease. Foods to eat: fruits, vegetables, berries, whole grains, legumes (beans), nuts, fish, a little wine, and some chicken. Foods to limit on this diet: butter, red meat, margarine, sweets and pastries, whole fat cheese, and fried or fast food. From Medical Xpress:

Eating away at cognitive decline: MIND diet may slow brain from aging by 7.5 years

While cognitive abilities naturally diminish as part of the normal aging process, it may be possible to take a bite out of this expected decline. Eating a group of specific foods known as the MIND diet may slow cognitive decline among aging adults, even when the person is not at risk of developing Alzheimer's disease, according to researchers at Rush University Medical Center. This finding is in addition to a previous study by the research team that found that the MIND diet may reduce a person's risk in developing Alzheimer's disease.

The recent study shows that older adults who followed the MIND diet more rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet least. The results of the study recently were published online in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

The National Institute of Aging funded study evaluated cognitive change over a period of 4.7 years among 960 older adults who were free of dementia on enrollment. Averaging 81.4 years in age....residents of more than 40 retirement communities and senior public housing units in the Chicago area. .... Martha Clare Morris, ScD, a nutritional epidemiologist, and colleagues developed the diet, whose full name is the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay. As the name suggests, the MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Both diets have been found to reduce the risk of cardiovascular conditions, like hypertension, heart attack and stroke.

"Everyone experiences decline with aging; and Alzheimer's disease is now the sixth leading cause of death in the U.S., which accounts for 60 to 80 percent of dementia cases. Therefore, prevention of cognitive decline, the defining feature of dementia, is now more important than ever," Morris says.

The MIND diet has 15 dietary components, including 10 "brain-healthy food groups" and five unhealthy groups - red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food. To adhere to and benefit from the MIND diet, a person would need to eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day—along with a glass of wine—snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. In addition, the study found that to have a real shot at avoiding the devastating effects of cognitive decline, he or she must limit intake of the designated unhealthy foods, especially butter (less than 1 tablespoon a day), sweets and pastries, whole fat cheese, and fried or fast food (less than a serving a week for any of the three).

Berries are the only fruit specifically to be included in the MIND diet. "Blueberries are one of the more potent foods in terms of protecting the brain," Morris says, and strawberries also have performed well in past studies of the effect of food on cognitive function.

People fear dementia and Alzheimer's disease, because they are progressive diseases that nothing treats successfully. However, in the past year there have been some studies showing improvements with lifestyle changes (not cures, but for some the progression was slowed or showing some improvements). The latest studies found that exercise (especially aerobic execise) had some beneficial effects on those with mild cognitive impairment (MCI), Alzheimer's disease, and vascular cognitive  impairment (VCI): neuropsychiatric improvements, improvements in biomarkers for the disease, and improved blood flow to the brain. From Medscape:

Physical Activity May Help Treat Dementia

New research shows that being physically active not only reduces cognitive decline and improves neuropsychiatric symptoms in patients with dementia but may actually reduce Alzheimer's disease (AD) biomarkers, including amyloid and tau protein in the brain. Exercise could also benefit patients with types of dementia other than AD, another study suggests.Some of this promising new research on exercise was presented at the Alzheimer's Association International Conference (AAIC) 2015. 

Danish researchers had already presented cognition-related results of the multicenter ADEX study ...The intervention consisted of 1 hour of aerobic exercise three times a week for 16 weeks. The control group received usual care..... The analysis found that these [neuropsychiatric] symptoms improved in the 66 patients in the "high exercise"group... The NI is a 12-item questionnaire that rates, among other things, depression, apathy, agitation, hallucinations, irritability, weight loss, and sleep."We saw that the control group got worse; there was a small decline in this group, which you would expect because this is progressive disease," said Steen Hasselbalch, MD, Danish Dementia Research Centre, Copenhagen, Denmark. "But the intervention group remained at the same level and even got a little better, so at end of the intervention there was a significant difference."

The question arises of whether exercise could not just delay worsening of symptoms but actually change brain pathology.The answer, suggests other research, is yes. In a separate study presented at the AAIC 2015, researchers found decreased phosphorylated tau (P tau) in older, previously sedentary persons completing a 6-month regimen of moderate- to high-intensity aerobic exercise.

The study enrolled 70 patients aged 55 to 89 years with prediabetes as well as amnestic mild cognitive impairment (MCI)....We think they are at high, high risk for developing dementia of the Alzheimer's type." These patients were randomly assigned to the aerobic exercise group or to the stretching group. Those in the aerobic group started slowly — 10 minutes of exercise a week — and gradually built the time and intensity up over 6 weeks to the point where they were exercising 45 minutes a day, 4 days a week, at 75% to 85% of their maximum heart rate...."This group had a choice of exercises: treadmill, stationary cycling, elliptical trainer, or preapproved group classes.

The stretching group, whose members could do balance exercises, gentle yoga, and other approved classes in addition to stretching, maintained a maximum heart rate of below 35%. All exercises were adapted to the needs and limitations of individual patients and were done at a local YMCA.

The researchers looked at biomarkers in cerebrospinal fluid (CSF), including P tau protein and amyloid β 42....Most intervention trials don't show such changes in P tau. "But we saw it with exercise and no medications," said Dr. Baker. "Exercise was enough to move a biomarker that indicates the severity of the disease."  It wasn't surprising, she added, that this was true only for older patients. "It may be that before age 70, you have a lot of compensatory mechanisms that help to maintain brain health, and after 70, those start breaking down."

The study also showed that the aerobic activity increased blood flow to the brain...The researchers demonstrated that the increased blood flow was in regions characteristically affected by aging and AD (ie, memory and processing).Cognitive benefits were particularly noteworthy for executive function..."Our brain imaging results are just fantastic; they show some really nice increases in blood flow in the areas of brain that support executive function and areas of the brain that normally show decreased flow for people with MCI, so it's reversing the blood flow detriment in MCI."

AD may not be the only dementia potentially treatable through exercise. Another study discussed at the meeting showed that this intervention may help those with vascular cognitive impairment (VCI)It's the first intervention trial to suggest that exercise can improve cognition in patients with confirmed VCI, said Teresa Liu- Ambrose, PhD, Canada Research Chair, University of British Columbia, Vancouver, Canada, who reported the results.The 6-month study included 71 patients aged 56 to 96 years with mild VCI of varying physical capacities. They were assigned to usual care that included a nutrition component or to an intervention of moderate-intensity walking, 3 times a week for an hour....In a subset of patients who had neuroimaging, there was "evidence of efficiency" in the brain of those who exercised, Dr Liu-Ambrose told Medscape Medical News.

Big question: will vitamin D supplementation prevent cognitive decline? And what should be a daily supplement dose for adults? An earlier post cited a Medscape article suggesting that taking 1000 IU of vitamin D3 daily would be a good daily level of supplementation. From Medscape:

Vitamin D Deficiency Predicts Cognitive Decline

A new study supports a link between low levels of vitamin D and increased risk for cognitive decline, prompting calls for clinical trials to test whether vitamin D supplementation may delay or prevent dementia. In a group of cognitively intact older adults, serum 25-hydroxyvitamin D (25OHD) levels below 75 nmol/L at the outset predicted cognitive decline over roughly the next 4 years, independent of other factors.

For this analysis, the researchers looked at data on 1927 community-dwelling elderly individuals (mean age, 73.9 years) participating in the Italian population-based cohort study, Progetto Veneto Anziani (Pro.V.A.).

Dr Toffanello and colleagues say studies are needed to evaluate whether vitamin D supplementation might help to delay the cognitive decline, especially in patients who already have cognitive impairment.

David J. Llewellyn, PhD, from the University of Exeter Medical School in the United Kingdom, who has studied vitamin D and cognitive function but wasn't involved in this study, agrees. He told Medscape Medical News that this new study "effectively replicates" a 2010 study by his group showing a link between low vitamin D levels and an increased risk for cognitive decline. He said the Pro.V.A . study results are also consistent with a study his group published just this year inNeurology. That study suggested older patients with vitamin D levels below 50 nmol/L have about a 122% increased risk for dementia compared with those with higher levels.

It would be exciting if vitamin D supplementation improves cognitive function in the elderly. From Science Daily:

Vitamin D deficiency, cognition appear to be linked in older adults

Vitamin D deficiency and cognitive impairment are common in older adults, but there isn't a lot of conclusive research into whether there's a relationship between the two.

"This study provides increasing evidence that suggests there is an association between low vitamin D levels and cognitive decline over time," said lead author Valerie Wilson, M.D., assistant professor of geriatrics at Wake Forest Baptist. "Although this study cannot establish a direct cause and effect relationship, it would have a huge public health implication if vitamin D supplementation could be shown to improve cognitive performance over time because deficiency is so common in the population."

Wilson and colleagues were interested in the association between vitamin D levels and cognitive function over time in older adults. They used data from the Health, Aging and Body composition (Health ABC) study to look at the relationship. The researchers looked at 2,777 well-functioning adults aged 70 to 79 whose cognitive function was measured at the study's onset and again four years later. Vitamin D levels were measured at the 12-month follow-up visit.

The Health ABC study cohort consists of 3,075 Medicare-eligible, white and black, well-functioning, community-dwelling older adults who were recruited between April 1997 and June 1998 from Pittsburgh, Pa., and Memphis, Tenn.

"With just the baseline observational data, you can't conclude that low vitamin D causes cognitive decline. When we looked four years down the road, low vitamin D was associated with worse cognitive performance on one of the two cognitive tests used," Wilson said. "It is interesting that there is this association and ultimately the next question is whether or not supplementing vitamin D would improve cognitive function over time."