A dear friend, only 85 years old, healthy and physically and mentally active (golf, tennis, bridge) has developed serious signs of mental decline. This has alarmed me sufficiently to review what recent research says about this:
Avoiding Dementia Part I
Avoiding Dementia Part II
Eating foods rich in vitamin E associated with lower dementia risk
Consuming more vitamin E through the diet appears to be associated with a lower risk of dementia and Alzheimer's disease, according to a report in the July issue of Archives of Neurology, one of the JAMA/Archives journals.
Oxidative stress—damage to the cells from oxygen exposure—is thought to play a role in the development of Alzheimer's disease, according to background information in the article. Experimental data suggest that antioxidants, nutrients that help repair this damage, may protect against the degeneration of nervous system cells. "Although clinical trials have shown no benefit of antioxidant supplements for Alzheimer's disease, the wider variety of antioxidants in food sources is not well studied relative to dementia risk; a few studies, with varying lengths of follow-up, have yielded inconsistent results," the authors write.
Elizabeth E. Devore, Sc.D., of Erasmus Medical Center, Rotterdam, the Netherlands, and colleagues assessed 5,395 participants 55 years and older who did not have dementia between 1990 and 1993. Participants underwent a home interview and two clinical examinations at the beginning of the study, and provided dietary information through a two-step process involving a meal-based checklist and a food questionnaire.
The researchers focused on four antioxidants: vitamin E, vitamin C, beta carotene and flavonoids. The major food sources of vitamin E were margarine, sunflower oil, butter, cooking fat, soybean oil and mayonnaise; vitamin C came mainly from oranges, kiwi, grapefruit juice, grapefruit, cauliflower, red bell peppers and red cabbage; beta carotene, from carrots, spinach, vegetable soup, endive and tomato; and flavonoids from tea, onions, apples and carrots.
Over an average of 9.6 years of follow-up, 465 participants developed dementia; 365 of those were diagnosed with Alzheimer's disease. After adjusting for other potentially related factors, the one-third of individuals who consumed the most vitamin E (a median or midpoint of 18.5 milligrams per day) were 25 percent less likely to develop dementia than the one-third of participants who consumed the least (a median of 9 milligrams per day). Dietary intake levels of vitamin C, beta carotene and flavonoids were not associated with dementia risk. Results were similar when only the participants diagnosed with Alzheimer's disease were assessed.
"The brain is a site of high metabolic activity, which makes it vulnerable to oxidative damage, and slow accumulation of such damage over a lifetime may contribute to the development of dementia," the authors write. "In particular, when beta-amyloid (a hallmark of pathologic Alzheimer's disease) accumulates in the brain, an inflammatory response is likely evoked that produces nitric oxide radicals and downstream neurodegenerative effects. Vitamin E is a powerful fat-soluble antioxidant that may help to inhibit the pathogenesis of dementia."
Future studies are needed to evaluate dietary intake of antioxidants and dietary risks, including different points at which consuming more antioxidants might reduce risk, the authors conclude.
High blood levels of vitamin E reduces risk of Alzheimer's
High levels of several vitamin E components in the blood are associated with a decreased risk for Alzheimer's disease (AD) in advanced age, suggesting that vitamin E may help prevent cognitive deterioration in elderly people. This is the conclusion reached in a Swedish study published in the July 2010 issue of the Journal of Alzheimer s Disease.
"Vitamin E is a family of eight natural components, but most studies related to Alzheimer s disease investigate only one of these components, ±-tocopherol", says Dr. Francesca Mangialasche, who led the study. "We hypothesized that all the vitamin E family members could be important in protecting against AD. If confirmed, this result has implications for both individuals and society, as 70 percent of all dementia cases in the general population occur in people over 75 years of age, and the study suggests a protective effect of vitamin E against AD in individuals aged 80+."
The study was conducted at the Aging Research Center (ARC), Karolinska Institutet, Stockholm, Sweden, in collaboration with the Institute of Gerontology and Geriatrics, University of Perugia, Italy. The study included a sample of 232 participants from the Kungsholmen Project, a population-based longitudinal study on aging and dementia in Stockholm (Kungsholmen parish). All participants were aged 80+ years and were dementia-free at the beginning of the study (baseline). After 6-years of follow-up, 57 AD cases were identified.
The blood levels of all eight natural vitamin E components were measured at the beginning of the study. Subjects with higher blood levels (highest tertile) were compared with subjects who had lower blood levels (lowest tertile) to verify whether these two groups developed dementia at different rates. The study found that subjects with higher blood levels of all the vitamin E family forms had a reduced risk of developing AD, compared to subjects with lower levels. After adjusting for various confounders, the risk was reduced by 45-54%, depending on the vitamin E component.
Dr Mangialasche notes that the protective effect of vitamin E seems to be related to the combination of the different forms. Another recent study indicated that supplements containing high doses of the E vitamin form ±-tocopherol may increase mortality, emphasizing that such dietary supplements, if not used in a balanced way, may be more harmful than previously thought.
Physical activity reduces risk of cognitive impairment in later life
Women who are physically active at any point over the life course (teenage, age 30, age 50, late life) have lower risk of cognitive impairment in late-life compared to those who are inactive, but teenage physical activity appears to be most important. This is the key finding of a study of over nine thousand women published today in the Journal of the American Geriatrics Society.
There is growing evidence to suggest that people who are physically active in mid- and late life have lower chance of dementia and more minor forms of cognitive impairment in old age. However, there is a poorer understanding of the importance of early life physical activity and the relative importance of physical activity at different ages. Researchers led by Laura Middleton, PhD, of Sunnybrook Health Sciences Centre, Canada, compared the physical activity at teenage, age 30, age 50, and late life against cognition of 9,344 women from Maryland, Minnesota, Oregon and Pennsylvania to investigate the effectiveness of activity at different life stages.
Of the participants, 15.5%, 29.7%, 28.1%, and 21.1% reported being physically inactive at teenage, at 30 years, at 50 years, and in late life respectively; the increase in cognitive impairment for those who were inactive was between 50% and 100% at each time point. When physical activity measures for all four ages were entered into a single model and adjusted for variables such as age, education, marital status, diabetes, hypertension, depressive symptoms, smoking, and BMI, only teenage physical activity status remained significantly associated with cognitive performance in old age.
"Our study shows that women who are regularly physically active at any age have lower risk of cognitive impairment than those who are inactive but that being physically active at teenage is most important in preventing cognitive impairment," said Middleton.
The researchers also found that women who were physically inactive at teenage but became physically active at age 30 and age 50 had significantly reduced odds of cognitive impairment relative to those who remained physically inactive. In contrast, being physically active at age 30 and age 50 was not significantly associated with rates of cognitive impairment in those women who were already physically active at teenage.
Middleton added, "As a result, to minimize the risk of dementia, physical activity should be encouraged from early life. Not to be without hope, people who were inactive at teenage can reduce their risk of cognitive impairment by becoming active in later life."
The researchers concluded that the mechanisms by which physical activity across the life course is related to late life cognition are likely to be multi-factorial. There is evidence to suggest that physical activity has a positive effect on brain plasticity and cognition and in addition, physical activity reduces the rates and severity of vascular risk factors, such as hypertension, obesity, and type II diabetes, which are each associated with increased risk of cognitive impairment.
"Low physical activity levels in today's youth may mean increased dementia rates in the future. Dementia prevention programs and other health promotion programs encouraging physical activity should target people starting at very young ages, not just in mid- and late life," said Middleton.
"Elderly people as a group are large consumers of vitamin E supplements, which usually contain only ±-tocopherol, and this often at high doses", says Dr Mangialasche. "Our findings need to be confirmed by other studies, but they open up for the possibility that the balanced presence of different vitamin E forms can have an important neuroprotective effect."
Vitamin D Promotes Mental Agility in Elders
At a time when consumer interest in health-enhancing foods is high, Agricultural Research Service (ARS)-funded scientists have contributed to a limited but growing body of evidence of a link between vitamin D and cognitive function.
Cognitive function is measured by the level at which the brain is able to manage and use available information for activities of daily life. Alzheimer's disease, the most common form of age-related dementia, affects about 47 percent of adults aged 85 years or older in the United States. Identifying nutritional factors that lower cognitive dysfunction and help preserve independent living provides economic and public health benefits, according to authors.
The study, which was supported by ARS, the National Institutes of Health, and others, was led by epidemiologist Katherine Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass. Tucker collaborated with HNRCA laboratory directors Irwin Rosenberg, Bess Dawson-Hughes and colleagues.
Metabolic pathways for vitamin D have been found in the hippocampus and cerebellum areas of the brain involved in planning, processing, and forming new memories. This suggests that vitamin D may be implicated in cognitive processes.
The study involved more than 1,000 participants receiving home care. The researchers evaluated associations between measured vitamin D blood concentrations and neuropsychological tests. Elders requiring home care have a higher risk of not getting enough vitamin D because of limited sunlight exposure and other factors.
The participants, ages 65 to 99 years, were grouped by their vitamin D status, which was categorized as deficient, insufficient, or sufficient. Only 35 percent had sufficient vitamin D blood levels. They had better cognitive performance on the tests than those in the deficient and insufficient categories, particularly on measures of "executive performance," such as cognitive flexibility, perceptual complexity, and reasoning. The associations persisted after taking into consideration other variables that could also affect cognitive performance.
The 2009 study appears in the Journals of Gerontology, Series A, Biological Sciences and Medical Sciences.
Abdominal fat at middle age associated with greater risk of dementia
Study confirms that obesity is associated with lower total brain volume
Researchers from Boston University School of Medicine determined that excess abdominal fat places otherwise healthy, middle-aged people at risk for dementia later in life. Preliminary findings suggest a relationship between obesity and dementia that could lead to promising prevention strategies in the future. Results of this study are published early online in Annals of Neurology, a journal of the American Neurological Association.
A 2005 World Health Organization (WHO) report estimated that 24.3 million people have some form of dementia, with 4.6 million new cases annually. Individuals with dementia exhibit a decline in short-term and long-term memory, language processing, problem solving capabilities, and other cognitive function. Clinical diagnosis of dementia is made when two or more brain functions are significantly impaired. Symptoms of dementia can be attributed to irreversible causes such Alzheimer's disease, vascular dementia, and Huntington's disease, or caused by treatable conditions such as brain tumor, medication reaction, or metabolic issues.
For the current study, Sudha Seshadri, M.D. and colleagues recruited participants from the Framingham Heart Study Offspring Cohort. The sample included 733 community participants who had a mean age of 60 years with roughly 70% of the study group comprised of women. Researchers examined the association between Body Mass Index (BMI), waist circumference, waist to hip ratio, CT-based measures of abdominal fat, with MRI measures of total brain volume (TCBV), temporal horn volume (THV), white matter hyperintensity volume (WMHV) and brain infarcts in the middle-aged participants.
"Our results confirm the inverse association of increasing BMI with lower brain volumes in older adults and with younger, middle-aged adults and extends the findings to a much larger study sample," noted Dr. Seshadri. Prior studies were conducted in cohorts with less than 300 participants and the current study includes over 700 individuals.
"More importantly our data suggests a stronger connection between central obesity, particularly the visceral fat component of abdominal obesity, and risk of dementia and Alzheimer's disease," Dr. Seshadri added. The research showed the association between VAT and TCBV was most robust and was also independent of BMI and insulin resistance. Researchers did not observe a statistically significant correlation between CT-based abdominal fat measures and THV, WMHV or BI.
"Our findings, while preliminary, provide greater understanding of the mechanisms underlying the link between obesity and dementia," concluded Dr. Seshadri. "Further studies will add to our knowledge and offer important methods of prevention."
Caffeine may slow Alzheimer's disease and other dementias, restore cognitive function
Although caffeine is the most widely consumed psychoactive drug worldwide, its potential beneficial effect for maintenance of proper brain functioning has only recently begun to be adequately appreciated. Substantial evidence from epidemiological studies and fundamental research in animal models suggests that caffeine may be protective against the cognitive decline seen in dementia and Alzheimer's disease (AD). A special supplement to the Journal of Alzheimer's Disease, "Therapeutic Opportunities for Caffeine in Alzheimer's Disease and Other Neurodegenerative Diseases," sheds new light on this topic and presents key findings.
Guest editors Alexandre de Mendonça, Institute of Molecular Medicine and Faculty of Medicine, University of Lisbon, Portugal, and Rodrigo A. Cunha, Center for Neuroscience and Cell Biology of Coimbra and Faculty of Medicine, University of Coimbra, Portugal, have assembled a group of international experts to explore the effects of caffeine on the brain. The resulting collection of original studies conveys multiple perspectives on topics ranging from molecular targets of caffeine, neurophysiological modifications and adaptations, to the potential mechanisms underlying the behavioral and neuroprotective actions of caffeine in distinct brain pathologies.
"Epidemiological studies first revealed an inverse association between the chronic consumption of caffeine and the incidence of Parkinson's disease," according to Mendonça and Cunha. "This was paralleled by animal studies of Parkinson's disease showing that caffeine prevented motor deficits as well as neurodegeneration "Later a few epidemiological studies showed that the consumption of moderate amounts of caffeine was inversely associated with the cognitive decline associated with aging as well as the incidence of Alzheimer's disease. Again, this was paralleled by animal studies showing that chronic caffeine administration prevented memory deterioration and neurodegeneration in animal models of aging and of Alzheimer's disease."
Exercise associated with preventing, improving mild cognitive impairment
Moderate physical activity performed in midlife or later appears to be associated with a reduced risk of mild cognitive impairment, whereas a six-month high-intensity aerobic exercise program may improve cognitive function in individuals who already have the condition, according to two reports in the January issue of Archives of Neurology, one of the JAMA/Archives journals.
Mild cognitive impairment is an intermediate state between the normal thinking, learning and memory changes that occur with age and dementia, according to background information in one of the articles. Each year, 10 percent to 15 percent of individuals with mild cognitive impairment will develop dementia, as compared with 1 percent to 2 percent of the general population. Previous studies in animals and humans have suggested that exercise may improve cognitive function.
In one article, Laura D. Baker, Ph.D., of the University of Washington School of Medicine and Veterans Affairs Puget Sound Health Care System, Seattle, and colleagues report the results of a randomized, controlled clinical trial involving 33 adults with mild cognitive impairment (17 women, average age 70). A group of 23 were randomly assigned to an aerobic exercise group and exercised at high intensity levels under the supervision of a trainer for 45 to 60 minutes per day, four days per week. The control group of 10 individuals performed supervised stretching exercises according to the same schedule but kept their heart rate low. Fitness testing, body fat analysis, blood tests of metabolic markers and cognitive functions were assessed before, during and after the six-month trial.
A total of 29 participants completed the study. Overall, the patients in the high-intensity aerobic exercise group experienced improved cognitive function compared with those in the control group. These effects were more pronounced in women than in men, despite similar increases in fitness. The sex differences may be related to the metabolic effects of exercise, as changes to the body's use and production of insulin, glucose and the stress hormone cortisol differed in men and women.
"Aerobic exercise is a cost-effective practice that is associated with numerous physical benefits. The results of this study suggest that exercise also provides a cognitive benefit for some adults with mild cognitive impairment," the authors conclude. "Six months of a behavioral intervention involving regular intervals of increased heart rate was sufficient to improve cognitive performance for an at-risk group without the cost and adverse effects associated with most pharmaceutical therapies."
In another report, Yonas E. Geda, M.D., M.Sc., and colleagues at Mayo Clinic, Rochester, Minn., studied 1,324 individuals without dementia who were part of the Mayo Clinic Study of Aging. Participants completed a physical exercise questionnaire between 2006 and 2008. They were then assessed by an expert consensus panel, who classified each as having normal cognition or mild cognitive impairment.
A total of 198 participants (median or midpoint age, 83 years) were determined to have mild cognitive impairment and 1,126 (median age 80) had normal cognition. Those who reported performing moderate exercise—such as brisk walking, aerobics, yoga, strength training or swimming—during midlife or late life were less likely to have mild cognitive impairment. Midlife moderate exercise was associated with 39 percent reduction in the odds of developing the condition, and moderate exercise in late life was associated with a 32 percent reduction. The findings were consistent among men and women.
Light exercise (such as bowling, slow dancing or golfing with a cart) or vigorous exercise (including jogging, skiing and racquetball) were not independently associated with reduced risk for mild cognitive impairment.
Physical exercise may protect against mild cognitive impairment via the production of nerve-protecting compounds, greater blood flow to the brain, improved development and survival of neurons and the decreased risk of heart and blood vessel diseases, the authors note. "A second possibility is that physical exercise may be a marker for a healthy lifestyle," they write. "A subject who engages in regular physical exercise may also show the same type of discipline in dietary habits, accident prevention, adherence to preventive intervention, compliance with medical care and similar health-promoting behaviors."
Future study is needed to confirm whether exercise is associated with the decreased risk of mild cognitive impairment and provide additional information on cause and effect relationships, they conclude.
High fruit and vegetable intake positively correlated with cognitive performance
Researchers at the Institute of Biochemistry and Molecular Biology I of the Heinrich-Heine University, Düsseldorf, Germany, investigated the relationship between fruit and vegetable intake, plasma antioxidant micronutrient status and cognitive performance in healthy subjects aged 45 to 102 years. Their results, published in the August issue of the Journal of Alzheimer's Disease, indicated higher cognitive performance in individuals with high daily intake of fruits and vegetables.
Subjects with a high daily intake (about 400 g) of fruits and vegetables had higher antioxidant levels, lower indicators of free radical-induced damage against lipids as well as better cognitive performance compared to healthy subjects of any age consuming low amounts (< 100 g/day) of fruits and vegetables. Modification of nutritional habits aimed at increasing intake of fruits and vegetables, therefore, should be encouraged to lower the prevalence of cognitive impairment.
The work was performed in collaboration with the Department of Pharmacology at Temple University in Philadelphia, Pennsylvania, the Department of Geriatrics at Perugia University, Italy, and the Department of Neurology of the St. Elisabeth Hospital in Cologne, Germany.
Dr. M. Cristina Polidori, currently at the Department of Geriatrics, Marienhospital Herne, Ruhr-University of Bochum, Germany, explains: "It is known that there is a strong association between fruit and vegetable intake and the natural antioxidant defenses of the body against free radicals. It is also known that bad nutritional habits increase the risk of developing cognitive impairment with and without dementia. With this work we show a multiple link between fruit and vegetable intake, antioxidant defenses and cognitive performance, in the absence of disease and independent of age. Among other lifestyle habits, it is recommended to improve nutrition in general and fruit and vegetable intake in particular at any age, beginning as early as possible. This may increase our chances to remain free of dementia in advanced age."
These findings are independentof age, gender, body mass index, level of education, lipid profile and albumin levels, all factors able to influence cognitive and antioxidant status. The relevance of the findings is also strengthened by the large sample that included 193 healthy subjects.
Further studies are planned that will include larger subject cohorts, patients with Alzheimer's disease at different stages and patients with mild cognitive impairment without dementia.
Mediterranean Diet = Slower Cognitive Decline
In an examination of the association between adherence to a Mediterranean-type diet and cognitive performance and risk of dementia, researchers found that high adherence to the diet was associated with slower decline in some measures of cognitive function but was not associated with decreased risk for dementia, according to a study in the August 12 , 2009 issue of JAMA.
Higher adherence to a Mediterranean-type diet is linked to lower risk for mortality and chronic diseases, and "might also have protective effects against cognitive decline in older individuals, because it combines several foods and nutrients potentially protective against cognitive dysfunction or dementia, such as fish, monounsaturated fatty acids, vitamins B12 and folate, antioxidants (vitamin E, carotenoids, flavonoids), and moderate amounts of alcohol," the authors write. But its association with cognitive decline has been unclear.
Catherine Féart, Ph.D., of the Université Victor Ségalen Bordeaux 2, Bordeaux, France, and colleagues examined whether adherence to a Mediterranean diet was associated with change in cognitive performance and with lower risk of all-cause dementia or Alzheimer disease. The study included 1,410 individuals (age 65 years or older) from Bordeaux, France, who were part of the Three-City cohort in 2001-2002 (a study of vascular risk factors of dementia) and were re-examined at least once over 5 years. Adherence to a Mediterranean diet (scored as 0 to 9) was computed from a food frequency questionnaire and 24-hour recall.
Cognitive performance was assessed on 4 neuropsychological tests: the Mini-Mental State Examination (MMSE), Isaacs Set Test (IST), Benton Visual Retention Test (BVRT), and Free and Cued Selective Reminding Test (FCSRT). New cases of dementia (n = 99) were validated by an independent expert committee of neurologists.
After adjusting for age, sex, education, marital status, energy intake, physical activity, depressive symptomatology, taking 5 medications/day or more, apolipoprotein E genotype, cardiovascular risk factors, and stroke, the researchers found that higher Mediterranean diet score was associated with fewer MMSE errors. But performance on the IST, BVRT, or FCSRT over time was not significantly associated with Mediterranean diet adherence, especially in those who remained free from dementia over 5 years. Mediterranean diet adherence was not associated with the risk for incident dementia, although the statistical strength of the data to detect a difference was limited.
"The Mediterranean diet pattern probably does not fully explain the better health of persons who adhere to it, but it may contribute directly. A Mediterranean diet also may indirectly constitute an indicator of a complex set of favorable social and lifestyle factors that contribute to better health. Further research is needed to allow the generalization of these results to other populations and to establish whether a Mediterranean diet slows cognitive decline or reduces incident dementia in addition to its cardiovascular benefits," the authors conclude.
Mediterranean diet, exercise fight Alzheimer disease
Elderly individuals who had a diet that included higher consumption of fruits, vegetables, legumes, cereal and fish and was low in red meat and poultry and who were physically active had an associated lower risk of Alzheimer disease, according to a study in the August 12. 2009 issue of JAMA.
Research regarding the effect physical activity can have on the risk of Alzheimer disease (AD) or dementia has shown mixed results, as has the effect of dietary habits. Their combined association has not been investigated, according to background information in the article.
Nikolaos Scarmeas, M.D., of Columbia University Medical Center, New York, and colleagues examined the association between physical activity and risk of AD and also the effect of physical activity and adherence to a Mediterranean-type diet on AD risk. The study included 2 groups that consisted of 1,880 community-dwelling elderly residents of New York city without dementia at the start of the study, for whom there was both diet and physical activity information available. Standardized neurological and neuropsychological measures were administered approximately every 1.5 years from 1992 through 2006.
The participants received measurements of their adherence to a Mediterranean-type diet (scale of 0-9; categorized as low, middle, or high) and their physical activity (sum of weekly participation in various physical activities, weighted by the type of physical activity [light, moderate, vigorous]; categorized into no physical activity, some, or much, also low or high), separately and combined. A higher score for diet was obtained with higher consumption of fruits, vegetables, legumes, cereals, and fish; lower consumption of meat and dairy products; a higher ratio of monounsaturated fats to saturated fats and mild to moderate alcohol consumption.
Individuals were followed up for an average of 5.4 years, during which a total of 282 developed AD. In considering only physical activity, the researchers found that more physical activity was associated with lower risk for developing AD. "Compared with physically inactive individuals, report of some physical activity was associated with a 29 percent to 41 percent lower risk of developing AD, while report of much physical activity was associated with a 37 percent to 50 percent lower risk," the authors write.
When considered simultaneously, both physical activity and Mediterranean diet adherence were significantly associated with AD incidence. According to the researchers, "Belonging to the middle diet adherence tertile was associated with a 2 percent to 14 percent risk reduction, while belonging to the highest diet adherence tertile was associated with a 32 percent to 40 percent reduced risk. Similarly, compared with individuals with no physical activity, individuals reporting some physical activity had a 25 percent to 38 percent lower risk for AD, while individuals reporting much physical activity had a 33 percent to 48 percent lower risk for AD."
The authors also write, "Compared with individuals with low physical activity plus low adherence to a diet (absolute AD risk, 19 percent), high physical activity plus high diet adherence was associated with a 35 percent to 44 percent relative risk reduction (absolute AD risk, 12 percent). … Absolute AD risks declined from 21 percent in the group with no physical activity plus low diet adherence to 9 percent in the group with much physical activity plus high diet adherence."
"In summary, our results support the potentially independent and important role of both physical activity and dietary habits in relation to AD risk. These findings should be further evaluated in other populations."
High cholesterol in midlife raises risk of late-life dementia
Elevated cholesterol levels in midlife – even levels considered only borderline elevated – significantly increase the risk of Alzheimer's disease and vascular dementia later in life, according to a new study by researchers at Kaiser Permanente's Division of Research and the University of Kuopio in Finland. The study appears in the journal Dementia & Geriatric Cognitive Disorders.
The four-decade study of 9,844 men and women found that having high cholesterol in midlife (240 or higher milligrams per deciliter of blood) increases, by 66 percent, the risk for Alzheimer's disease later in life. Even borderline cholesterol levels (200 – 239 mg/dL) in midlife raised risk for late-life vascular dementia by nearly the same amount: 52 percent. Vascular dementia, the second most common form of dementia after Alzheimer's disease, is a group of dementia syndromes caused by conditions affecting the blood supply to the brain. Scientists are still trying to pinpoint the genetic factors and lifestyle causes for Alzheimer's disease.
By measuring cholesterol levels in 1964 to 1973 based on the 2002 Adult Treatment Panel III guidelines (the current practice standard) when the Kaiser Permanente Northern California members were 40 to 45 years old, then following the participants for 40 years, this study is the largest long-term study with the most diverse population to examine the midlife cholesterol levels and late-life dementia. It is also the first study to look at borderline high cholesterol levels and vascular dementia, rather than just Alzheimer's disease.
"Our study shows that even moderately high cholesterol levels in your 40s puts people at greater risk for Alzheimer's disease and vascular dementia decades later," said the study's senior author. Rachel Whitmer, Ph.D., a research scientist and epidemiologist at the Kaiser Permanente Division of Research in Oakland, Calif. "Considering that nearly 100 million Americans have either high or borderline cholesterol levels, this is a disturbing finding. The good news here is that what is good for the heart is also good for the mind, and this is an early risk factor for dementia that can be modified and managed by lowering cholesterol through healthy lifestyle changes."
This study, funded by the National Institutes of Health, adds to other research emphasizing the importance of addressing dementia risk factors in midlife, before an underlying disease or symptoms appear, the researchers said.
"Our findings add to the existing body of evidence on a degree of overlap between two dementia types in terms of risk factors, symptoms and neuropathology," said the study's lead author, Alina Solomon, MD, a researcher with the Department of Neurology at the University of Kuopio, Finland. "Dementia and cardiovascular disease are common major health problems, share several risk factors and often occur simultaneously, interacting with one another. A holistic approach that addresses multiple major health problems simultaneously is needed to effectively manage these disorders."
The study tracked members of Kaiser Permanente's Northern California Medical Group from 1967 to 2007 by using the multiphasic testing records pioneered by Kaiser Permanente founding physician Morris Collen, MD, who is widely regarded worldwide as a health care informatics pioneer. Of the original 9,844 participants, 598 were diagnosed with Alzheimer's disease or vascular dementia between 1994 and 2007, when the participants were between 61 and 88 years old.
This epidemiological study did not examine the mechanism of the link between cholesterol levels and dementia.
This study is part of an ongoing body of research at Kaiser Permanente to better understand the risk and protective factors for dementia. Dr. Whitmer recently authored two dementia-related studies: one that found a larger abdomen in midlife increases risk of late-life dementia, and one that showed that low blood sugar events in elderly patients with type 2 diabetes increase their risk for dementia. Another Kaiser Permanente study, led by Valerie Crooks of Kaiser Permanente in Southern California, found that having a strong social network of friends and family appears to decrease risk for dementia.
Dietary Approaches to Stop Hypertension (DASH) Eating Pattern May Reduce Age-Related Cognitive Decline
The Dietary Approaches to Stop Hypertension (DASH) diet is often recommended by physicians to people with high blood pressure or pre-hypertension. The DASH diet eating plan has been proven to lower blood pressure in studies sponsored by the National Institutes of Health. High blood pressure is considered a risk factor for Alzheimer's and dementia.
Heidi Wengreen, RD, PhD, Assistant Professor of Nutrition at Utah State University, and colleagues examined associations between how closely people adhered to the DASH diet and risk of cognitive decline and dementia among older participants in the Cache County Study on Memory, Health and Aging.
In 1995, 3,831 study participants 65 years of age or older completed a survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was checked again during four assessments over 11 years using the Modified Mini-Mental State examination (3MS), which is graded on a 100 point scale. A DASH diet adherence score was created based on consumption levels of nine food-group/nutrient components -- fruit, vegetables, nut/legumes, whole grains, low-fat dairy, sodium, sweets, non-fish meat, and fish. Participants were ranked by DASH score into five groups, or quintiles.
The researchers found that higher DASH scores were associated with higher scores for cognitive functioning at the beginning of the study and over time. Those in the highest quintile scored 1.42 points higher at baseline and 1.81 points higher after 11 years on the 3MS than did those in the lowest quintile of the DASH score (p-values < 0.001).
They also found that four of the nine food-group/nutrient components used to create the DASH score were independently associated with 3MS scores -- vegetables, whole grains, low-fat dairy, nut/legumes. The scientists created a diet adherence score based on just these four components which they then tested for association with changes in cognitive abilities on the 3MS. Those in the highest quintile scored 1.72 points higher at baseline and 3.73 points higher after 11 years than did those in the lowest quintile of the four-component score (p-values < 0.001).
"Our results suggest that including whole grains, vegetables, low-fat dairy foods, and nuts in one's diet may offer benefits for cognition in late life," Wengreen said. "However, we need more research before we can confidently say how much of these foods to include in your diet to experience some benefit."
Maintaining or Increasing Activity Levels May Slow Cognitive Decline in Elderly
Studies have found that older adults who are physically active may experience slower rates of cognitive decline. Less is known about the impact of changes in physical activity levels on rate of cognitive decline.
Deborah E. Barnes, PhD, MPH, Assistant Professor of Psychiatry at the University of California, San Francisco, and a geriatrics researcher at the San Francisco VA Medical Center, and colleagues studied changes in levels of both physical activity and cognitive function over seven years in 3,075 white and black elders aged 70-79 years in the Health, Aging and Body Composition Study. Physical activity was assessed based on self-reported number of minutes walked per week at the beginning of the study and after two, four, and seven years of follow-up. Participants were classified at each time point as sedentary (0 minutes per week), low (less than 150 minutes per week) or high (150 minutes per week or more). Changes over time were classified as consistently sedentary, maintaining (low or high), decreasing, or increasing/fluctuating. Cognitive function was assessed using the 3MS.
The researchers found that 21% of study participants were consistently sedentary, 12% maintained their activity levels, 26% had declining levels, and 41% had increasing or fluctuating levels. After adjustment for age, sex, race, education, study site, diabetes, hypertension, smoking, alcohol consumption and baseline 3MS score, they found that the mean rate of decline in 3MS scores was 0.62 points/year in those who were consistently sedentary, 0.54 points/year (p=0.30) in those with declining activity levels, 0.44 points/year (p=0.01) in those with increasing/fluctuating activity levels, and 0.40 points/year (p=0.04) in those who maintained their activity levels.
"We found that older adults who were sedentary throughout the study had the lowest levels of cognitive function at the beginning and experienced the fastest rate of cognitive decline," Barnes said. "Cognitive decline also was faster in those whose physical activity levels consistently declined during the study period."
According to the researchers, sedentary elders who began new aerobic exercise programs experienced improvements in cognitive function, especially the ability to process complex information quickly. "Sedentary individuals should be encouraged to engage in physical activity at least occasionally," Barnes said. "People who are currently active should be encouraged to maintain or increase their activity levels."
Moderate Long-Term Physical Activity May Improve Late Life Cognition; Long-Term Strenuous Activity May Increase Risk of Cognitive Impairment
Long-term strenuous physical activity has been shown to decrease lifetime exposure to ovarian hormones in women and has been found to play a protective role against breast cancer. However reduction in ovarian hormone exposure has been associated with increased risk of cognitive impairment. At the same time, long-term physical activity is associated with improved cognition but the intensity required to preserve cognition is not known.
Mary C. Tierney, PhD, CPsych, Professor of Family and Community Medicine at the University of Toronto, and Senior Scientist and Director, Geriatric Research Unit, Brain Sciences Program at Sunnybrook Health Sciences Centre, and colleagues sought to examine the associations between both long-term strenuous and moderate activity levels and cognition in recently postmenopausal women.
Study participants were 90 women aged 50-63 years, one to 10 years post natural menopause, with no history of breast cancer, HRT use, psychiatric disorder, dementia or other neurological condition. Participants gave details on the amount of their strenuous and moderate physical recreational activities from high school to menopause. Eight memory and brain function tests were administered to all participants.
After adjusting for age, education, reproductive years, cigarette smoking, alcohol consumption, parity, and periods of amenorrhea, the researchers found that long-term strenuous activity was consistently associated with poorer performance on all eight of the tests; with statistically significant results on tests of semantic memory, working memory, delayed verbal recall, and sustained attention (p < 0.05). Moderate physical activity was consistently associated with better performance on all eight of the tests, with statistically significant results on cognitive flexibility, working memory, and sustained attention (p < 0.05).
"Our results suggest that long-term strenuous activity may increase the risk of cognitive impairment in recently postmenopausal women," Tierney said. "On the other hand, moderate long-term physical activity may improve later life cognition. These preliminary findings have important implications for women's health and support the need for large-scale studies including both women and men."
Moderate alcohol intake has cognitive benefits
A glass of wine here, a nightcap there – new research out of Wake Forest University School of Medicine suggests that moderate alcohol intake offers long-term cognitive protection and reduces the risk of dementia in older adults.
The study is being presented at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease (ICAD), in Vienna on July 13.
While previous studies have shown that moderate alcohol intake, particularly wine, is linked with lower risk of heart attacks and dementia, most of the studies have been done in middle-aged people, and it has remained unclear if the benefits of alcohol also apply to older adults in general or to older adults who might already have some mild memory problems. This is the largest, longest U.S. study to look at the effects of regular alcohol intake on dementia in seniors, both with and without memory problems.
"As of yet, we still have no cure for Alzheimer's disease and other dementias, so it is important to look for things that might help people prevent the disease," said Kaycee Sink, M.D., M.A.S (Masters of Advanced Studies in clinical research), a geriatrician and senior author of the paper. Moderate alcohol intake has been linked to lower risk of heart attacks, stroke, dementia, and death in middle-aged adults, but there is still controversy about alcohol intake in older adults."
For the study, researchers began by examining and interviewing 3,069 individuals, 75 years or older and most without any memory or thinking problems, about their drinking habits. Participants were asked about beer, wine, and liquor. The investigators then categorized the individuals as abstainers (non-drinkers), light drinkers (one to seven drinks per week), moderate drinkers (eight to 14 drinks per week), or heavy drinkers (more than 14 drinks per week). All types of alcohol were included.
The study subjects were then examined and interviewed every six months for six years to determine changes in their memory or thinking abilities and to monitor who developed dementia.
Researchers found that individuals who had no cognitive impairment at the start of the study and drank eight to 14 alcoholic beverages per week, or one to two per day, experienced an average 37 percent reduction in risk of developing dementia compared to individuals who did not drink at all and were classified as abstainers. The type of alcohol consumed did not matter.
For older adults who started the study with mild cognitive impairment, however, consumption of alcohol, at any amount, was associated with faster rates of cognitive decline. In addition, those who were classified in the heavy drinker category, consuming more than 14 drinks per week, were almost twice as likely to develop dementia during the study compared to non-drinkers with mild cognitive impairment.
"We were excited to see that even in older adults, moderate alcohol intake decreases the risk of dementia," Sink said. "It is important to note, however, that our study found a significantly higher risk of dementia for heavy drinkers who started the study with mild cognitive impairment."
The results are consistent with previous studies of middle-aged adults that suggest mild to moderate alcohol intake may reduce the risk of dementia, except in the case of individuals who already have mild to moderate cognitive impairment. The researchers' findings support current recommendations not to exceed one drink per day for women and two for men.
It is unclear from this study whether an abstainer who begins drinking moderately in his/her 70s will experience the same benefit or if the benefit is associated with a long pattern of moderate alcohol intake that continues on into old age.
"Our results suggest that older adults who are normal cognitively and drink moderately do not need to change their drinking behavior," Sink said. "If you have mild cognitive impairment however, it might benefit you to restrict your drinking and certainly not exceed one drink a day for women and two drinks a day for men.
"The participants in this study self-reported their alcohol intake at the start, but it is unusual for people to start drinking in their 70s, so we assume that the habits they reported at the start of the study reflect stable drinking habits," Sink added. "Without scientific data showing that it is beneficial, I wouldn't recommend that non-drinkers start drinking in their 70s.
"We are starting to make progress in understanding how to prevent and treat Alzheimer's and other dementias," she said. "It is a very exciting time to be involved in geriatrics research."
Aspirin can reduce risk of Alzheimer's disease
Ibuprofen, aspirin, naproxen may be equally effective at reducing risk of Alzheimer's disease
Different types of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, naproxen, and aspirin, appear to be equally effective in lowering the risk of Alzheimer’s disease, according to the largest study of its kind published in the May 28, 2008, online issue of Neurology®, the medical journal of the American Academy of Neurology. Experts have debated whether a certain group of NSAIDs that includes ibuprofen may be more beneficial than another group that includes naproxen and aspirin.
Using information from six different studies, researchers examined data on NSAID use in 13,499 people without dementia. Over the course of these six studies, 820 participants developed Alzheimer’s disease.
Researchers found that people who used NSAIDs had 23 percent lower risk of developing Alzheimer’s disease compared to those who never used NSAIDs. The risk reduction did not appear to depend upon the type of NSAID taken.
“This is an interesting finding because it seems to challenge a current theory that the NSAID group which includes ibuprofen may work better in reducing a person’s risk of Alzheimer’s,” said study author Peter P. Zandi, PhD, with Johns Hopkins Bloomberg School of Public Health in Baltimore, MD. “The NSAID group that includes ibuprofen was thought to target a certain type of plaque in the brain found in Alzheimer’s patients. But our results suggest there may be other reasons why these drugs may reduce the risk of Alzheimer’s.”
The study’s lead author Chris Szekely, PhD, with Cedars Sinai Medical Center in Los Angeles, says the discrepancy between studies such as this one and the negative clinical trials of NSAIDs in treatment or prevention of Alzheimer’s need to be further explored.
Vasectomy may put men at risk for type of dementia
Northwestern University researchers have discovered men with an unusual form of dementia have a higher rate of vasectomy than men the same age who are cognitively normal.
The dementia is Primary Progressive Aphasia (PPA), a neurological disease in which people have trouble recalling and understanding words. In PPA, people lose the ability to express themselves and understand speech. It differs from typical Alzheimer's disease in which a person's memory becomes impaired.
Sandra Weintraub, principal investigator and professor of psychiatry and behavioral sciences and of neurology at Northwestern's Feinberg School of Medicine, began investigating a possible link between the surgery and PPA when one of her male patients connected the onset of his language problem at age 43 to the period after his vasectomy.
At a twice-yearly Chicago support group for PPA patients Weintraub sees from around the country, the male patient rushed into the room and asked the men sitting there, "OK, guys, how many of you have PPA?" Nine hands went up.
"How many of you had a vasectomy?" he demanded next. Eight hands shot up.
Weintraub and her team of researchers surveyed 47 men with PPA who were being treated at Northwestern's Cognitive Neurology and Alzheimer's Disease Center and 57 men with no cognitive impairment who were community volunteers. They ranged from 55 to 80 years old.
Of the non-impaired men, 16 percent had undergone a vasectomy. In contrast, 40 percent of the men with PPA had had the surgery.
"That's a huge difference," said Weintraub, director of neuropsychology in the Cognitive Neurology and Alzheimer's Disease Center. "It doesn't mean having a vasectomy will give you this disease, but it may be a risk factor to increase your chance of getting it."
In addition, the men who had undergone a vasectomy developed PPA at a younger age (58 years) than men with PPA who hadn't had one (62 years.)
While PPA robs people of their ability to speak and understand language, an unusual twist of the disease is patients are still able to maintain their hobbies and perform other complicated tasks for a number of years before other symptoms develop. Some people garden, build cabinets and even navigate a city subway system. By contrast, Alzheimer's patients lose interest in their hobbies, family life and may become idle. As PPA progresses over a number of years, however, patients eventually lose their ability to function independently.
Preliminary evidence from the study also seemed to connect another form of dementia to a vasectomy. In a smaller group of 30 men with a dementia called frontotemporal dementia (FTD,) 37 percent had undergone a vasectomy. The earliest symptoms of FTD are personality changes, lack of judgment and bizarre behavior. As in PPA, FTD usually starts at an earlier age, in the 40s and 50s.
One of Weintraub's patients with FTD was eating lunch in a restaurant with his family and excused himself to go to the bathroom. When he hadn't returned after 10 minutes, his sons went to investigate. They found him doing pushups on the bathroom floor. Other FTD patients begin shoplifting, compulsively gambling, misspending large amounts of money or become sexually demanding.
The most common form of dementia caused by brain deterioration in individuals over age 65 is Alzheimer's disease. Weintraub did not find an increased rate of vasectomy in patients with Alzheimer's.
Many patients with FTD and PPA share a common brain disease that is completely different from Alzheimer's. Whether a patient will get the behavioral or language problems depends on where the disease causes the most destruction in the brain. In FTD, most of the damage is in the frontal lobes; in PPA, it's in the language centers of the left hemisphere of the brain.
Weintraub theorizes a vasectomy may raise the risk of PPA (and possibly FTD) because the surgery breeches the protective barrier between the blood and the testes, called the blood-testis barrier.
Certain organs – including the testes and the brain – exist in what is the equivalent of a gated community in the body. Tiny tubes within the testes (in which sperm are produced) are protected by a physical barrier of Sertoli cells. The tight connections between these cells prevent blood-borne infections and poisonous molecules from entering the semen.
After a vasectomy, however, the protective barrier is broken and semen mixes into the blood. The immune system recognizes the sperm as invading foreign agents and produces anti-sperm antibodies in 60 to 70 percent of men.
Weintraub said these antibodies might cross the blood-brain-barrier and cause damage resulting in dementia. "There are other neurological models of disease which you can use as a parallel," Weintraub said. Certain malignant tumors produce antibodies that reach the brain and cause an illness similar to encephalitis, she noted.
The next step in Weintraub's research will be to launch a national study to see if her results will be confirmed in a larger population.
"I don't want to scare anyone away from getting a vasectomy," Weintraub stressed. "It's obviously a major birth control alternative. This is just a correlational observation," she said of the dementia connection. "We need to do more research to find out."
Higher folate levels linked to reduced risk for Alzheimer's disease
Individuals who take in higher levels of the nutrient folate through both diet and supplements may have a reduced risk of developing Alzheimer's disease, according to a report in the January issue of Archives of Neurology, one of the JAMA/Archives journals.
By the year 2047, the prevalence of Alzheimer's disease is expected to quadruple, according to background information in the article. Delaying the onset of this neurodegenerative disease would significantly reduce the burden it causes. Researchers suspect that elevated levels of the amino acid homocysteine in the blood, which is linked to a higher risk for cardiovascular disease and stroke, may also increase the risk for Alzheimer's disease. Folate, vitamin B12 and vitamin B6, are important in the body's processing of homocysteine--therefore, deficiencies in these nutrients increase homocysteine levels and may contribute to cardiovascular disease, stroke and dementia.
José A. Luchsinger, M.D., Columbia University Medical Center, New York, and colleagues examined, interviewed and assessed the diets of 965 individuals without dementia between 1992 and 1994 and then followed them for an average of 6.1 years to see if they developed Alzheimer's disease. The participants had an average age of 75.8 and 70.2 percent were women, 32.6 percent African-American, 45.3 percent Hispanic and 22.1 percent white.
During the follow-up period, 192 of the participants developed Alzheimer's disease. When the individuals were divided into four groups based on the total level of folate they took in through food and supplements and the analysis was adjusted for patient characteristics, comorbid diseases and B12 and B6 intake, the risk of Alzheimer's disease was lower in the groups with higher intake. Neither dietary folate nor supplements alone were significantly linked to Alzheimer's disease risk; only the two in combination appeared to produce an effect. Levels of the vitamins B12 and B6 were not associated with Alzheimer's disease risk.
Higher folate intake was modestly correlated with lower homocysteine levels, "indirectly suggesting that a lower homocysteine level is a potential mechanism for the association between higher folate intake and a lower Alzheimer's disease risk," the authors write.
Definitive conclusions about the role of folate in the development of Alzheimer's disease cannot yet be made, they continue. The findings of this study are in contrast to those of some other research, and other compounds (such as hormones) perceived to reduce the risk for dementia in observational studies did not do so in randomized trials. "Thus, the decision to increase folate intake to prevent Alzheimer's disease should await clinical trials," they conclude.
Red wine again linked to slowing Alzheimer's
A Mount Sinai School of Medicine study found giving mice with amyloid plaques red wine slows their memory loss and brain cell death - adding to a body of science linking compounds in the beverage to slowing the Alzheimer's disease-related symptom.
In the study - set to for publication in November's Federation of American Societies for Experimental Biology Journal - wine-drinking mice learned to escape from a maze significantly faster than mice drinking alcohol-spiked water or water.
The results could have implications for formulators in the production of supplements for age-related conditions.
According to the Alzheimers Society, there are nearly 18 million people in the world with dementia. Around 55 percent of those who suffer from dementia have Alzheimer's.
In the Mount Sinai study, the mice's wine intake was aligned to what is the equivalent of moderate consumption in humans - a five-ounce glass per day for women and two for men.
In the past, both alcohol and a red wine compound, resveratrol, have been linked to a reduction in the onset of dementia.
For several months, the Mount Sinai mice were given cabernet sauvignon or ethanol in their drinking water, while another group of mice drank plain water. All the mice had amyloid plaques in their brains that occur in humans with Alzheimer's disease.
The research team, led by Dr. Giulio Maria Pasinetti, assessed the mice's memory by testing their ability to get out of a maze. The wine-drinking mice were able to exit the maze significantly faster than those drinking alcohol-spiked water or water only, the scientists found.
The study only advocates moderate red wine consumption as part of an overall healthy lifestyle.
Midlife Coffee And Tea Drinking May Protect Against Late-life Dementia
Midlife coffee drinking can decrease the risk of dementia/Alzheimer's disease (AD) later in life. This conclusion is made in a Finnish Cardiovascular Risk Factors, Aging and Dementia (CAIDE) Study published in the Journal of Alzheimer's Disease.
This study has been conducted at the University of Kuopio, Finland in collaboration with Karolinska Institutet, Stockholm, Sweden, and the National Public Health Institute, Helsinki, Finland. The study included participants from the survivors of population-based cohorts previously surveyed within the North Karelia Project and the FINMONICA study in 1972, 1977, 1982 or 1987 (midlife visit). After an average follow-up of 21 years, 1409 individuals (71%) aged 65 to 79 completed the re-examination in 1998. A total of 61 cases were identified as demented (48 with AD).
"We aimed to study the association between coffee and tea consumption at midlife and dementia/AD risk in late-life, because the long-term impact of caffeine on the central nervous system was still unknown, and as the pathologic processes leading to Alzheimer's disease may start decades before the clinical manifestation of the disease," says lead researcher, associate professor Miia Kivipelto, from the University of Kuopio, Finland and Karolinska Institutet, Stockholm, Sweden.
At the midlife examination, the consumption of coffee and tea was assessed with a previously validated semi-quantitative food-frequency questionnaire. Coffee drinking was categorized into three groups: 0-2 cups (low), 3-5 cups (moderate) and >5 cups (high) per day. Further, the question concerning tea consumption was dichotomized into those not drinking tea (0 cup/day) vs. those drinking tea (≥1 cup/day).
The study found that coffee drinkers at midlife had lower risk for dementia and AD later in life compared to those drinking no or only little coffee. The lowest risk (65% decreased) was found among moderate coffee drinkers (drinking 3-5 cups of coffee/day). Adjustments for various confounders did not change the results. Tea drinking was relatively uncommon and was not associated with dementia/AD.
Kivipelto also notes that, "Given the large amount of coffee consumption globally, the results might have important implications for the prevention of or delaying the onset of dementia/AD. The finding needs to be confirmed by other studies, but it opens the possibility that dietary interventions could modify the risk of dementia/AD. Also, identification of mechanisms of how coffee exerts its protection against dementia/AD might help in the development of new therapies for these diseases."
In women, caffeine may protect memory
Caffeine may help older women protect their thinking skills, according to a study published in the August 7, 2007, issue of Neurology, the medical journal of the American Academy of Neurology.
The study found that women age 65 and older who drank more than three cups of coffee (or the equivalent in tea) per day had less decline over time on tests of memory than women who drank one cup or less of coffee or tea per day. The results held up even after researchers adjusted for other factors that could affect memory abilities, such as age, education, disability, depression, high blood pressure, medications, cardiovascular disease, and other chronic illnesses.
“Caffeine is a psychostimulant which appears to reduce cognitive decline in women,” said study author Karen Ritchie,. “While we have some ideas as to how this works biologically, we need to have a better understanding of how caffeine affects the brain before we can start promoting caffeine intake as a way to reduce cognitive decline. But the results are interesting – caffeine use is already widespread and it has fewer side effects than other treatments for cognitive decline, and it requires a relatively small amount for a beneficial effect.”
The study involved 7,000 people whose cognitive abilities and caffeine consumption were evaluated over four years. Compared to women who drank one cup or less of coffee per day, those who drank over three cups were less likely to show as much decline in memory. Moreover, the benefits increased with age – coffee drinkers being 30 percent less likely to have memory decline at age 65 and rising to 70 percent less likely over age 80.
Coffee could protect against Alzheimer's disease
A daily dose of caffeine blocks the disruptive effects of high cholesterol that scientists have linked to Alzheimer's disease. A study in the open access publication, Journal of Neuroinflammation revealed that caffeine equivalent to just one cup of coffee a day could protect the blood-brain barrier (BBB) from damage that occurred with a high-fat diet.
The BBB protects the central nervous system from the rest of the body's circulation, providing the brain with its own regulated microenvironment. Previous studies have shown that high levels of cholesterol break down the BBB which can then no longer protect the central nervous system from the damage caused by blood borne contamination. BBB leakage occurs in a variety of neurological disorders such as Alzheimer's disease.
In this study, researchers from the University of North Dakota School of Medicine and Health Sciences gave rabbits 3 mg caffeine each day – the equivalent of a daily cup of coffee for an average-sized person. The rabbits were fed a cholesterol-enriched diet during this time.
After 12 weeks a number of laboratory tests showed that the BBB was significantly more intact in rabbits receiving a daily dose of caffeine.
“Caffeine appears to block several of the disruptive effects of cholesterol that make the blood-brain barrier leaky,” says Jonathan Geiger, University of North Dakota School of Medicine and Health Sciences. “High levels of cholesterol are a risk factor for Alzheimer's disease, perhaps by compromising the protective nature of the blood-brain barrier. For the first time we have shown that chronic ingestion of caffeine protects the BBB from cholesterol-induced leakage.”
Caffeine appears to protect BBB breakdown by maintaining the expression levels of tight junction proteins. These proteins bind the cells of the BBB tightly to each other to stop unwanted molecules crossing into the central nervous system.
The findings confirm and extend results from other studies showing that caffeine intake protects against memory loss in aging and in Alzheimer’s disease.
“Caffeine is a safe and readily available drug and its ability to stabilise the blood-brain barrier means it could have an important part to play in therapies against neurological disorders,” says Geiger.
New study provides further evidence that apple juice can delay onset of Alzheimer's disease
A growing body of evidence demonstrates that we can take steps to delay age-related cognitive decline, including in some cases that which accompanies Alzheimer's disease, according to a study published in the January 2009 issue of the Journal of Alzheimer's Disease.
Thomas B. Shea, PhD, of the Center for Cellular Neurobiology; Neurodegeneration Research University of Massachusetts, Lowell and his research team have carried out a number of laboratory studies demonstrating that drinking apple juice helped mice perform better than normal in maze trials, and prevented the decline in performance that was otherwise observed as these mice aged.
In the most recent study Shea and his team demonstrated that mice receiving the human equivalent of 2 glasses of apple juice per day for 1 month produced less of a small protein fragment, called "beta-amyloid" that is responsible for forming the "senile plaques" that are commonly found in brains of individuals suffering from Alzheimer's disease.
Dr. Shea commented that "These findings provide further evidence linking nutritional and genetic risk factors for age-related neurodegeneration and suggest that regular consumption of apple juice can not only help to keep one's mind functioning at its best, but may also be able to delay key aspects of Alzheimer's disease and augment therapeutic approaches."
The article is "Dietary Supplementation with Apple Juice Decreases Endogenous Amyloid-_ Levels in Murine Brain" by Amy Chan and Thomas B. Shea. It is published in the Journal of Alzheimer's Disease 16:1 (January 2009).
Exercise helps prevent age-related brain changes in older adults
Older adults who exercise regularly show increased cerebral blood flow and a greater number of small blood vessels in the brain, according to findings presented at the annual meeting of the Radiological Society of North America (RSNA).
The study, conducted at the University of North Carolina (UNC) – Chapel Hill, is the first to compare brain scans of older adults who exercise to brain scans of those who do not.
"Our results show that exercise may reduce age-related changes in brain vasculature and blood flow," said presenter Feraz Rahman, M.S., currently a medical student at Jefferson Medical College in Philadelphia. "Other studies have shown that exercise prevents cognitive decline in the elderly. The blood vessel and flow differences may be one reason."
The researchers recruited 12 healthy adults, age 60 to 76. Six of the adults had participated in aerobic exercise for three or more hours per week over the last 10 years, and six exercised less than one hour per week. All of the volunteers underwent MRI to determine cerebral blood flow and MR angiography to depict blood vessels in the brain.
Using a novel method of three-dimensional (3-D) computer reconstruction developed in their lab, the researchers were able to make 3-D models of the blood vessels and examine them for shape and size. They then compared the blood vessel characteristics and how they related to blood flow in both the active and inactive groups.
The results showed that the inactive group exhibited fewer small blood vessels in the brain, along with more unpredictable blood flow through the brain.
"The active adults had more small blood vessels and improved cerebral blood flow," said the study's senior author, J. Keith Smith, M.D., Ph.D., associate professor of radiology at UNC School of Medicine. "These findings further point out the importance of regular exercise to healthy aging."
Red wine: How it fights Alzheimer's
Alzheimer's researchers at UCLA, in collaboration with Mt. Sinai School of Medicine in New York, have discovered how red wine may reduce the incidence of the disease. Reporting in the Nov. 21 issue of the Journal of Biological Chemistry, David Teplow, a UCLA professor of neurology, and colleagues show how naturally occurring compounds in red wine called polyphenols block the formation of proteins that build the toxic plaques thought to destroy brain cells, and further, how they reduce the toxicity of existing plaques, thus reducing cognitive deterioration.
Polyphenols comprise a chemical class with more than 8,000 members, many of which are found in high concentrations in wine, tea, nuts, berries, cocoa and various plants. Past research has suggested that such polyphenols may inhibit or prevent the buildup of toxic fibers composed primarily of two proteins — Aß40 and Aß42 — that deposit in the brain and form the plaques which have long been associated with Alzheimer's. Until now, however, no one understood the mechanics of how polyphenols worked.
Teplow's lab has been studying how amyloid beta (Aß) is involved in causing Alzheimer's. In this work, researchers monitored how Aß40 and Aß42 proteins folded up and stuck to each other to produce aggregates that killed nerve cells in mice. They then treated the proteins with a polyphenol compound extracted from grape seeds. They discovered that polyphenols carried a one-two punch: They blocked the formation of the toxic aggregates of Aß and also decreased toxicity when they were combined with Aß before it was added to brain cells.
"What we found is pretty straightforward," Teplow said. "If the Aß proteins can't assemble, toxic aggregates can't form, and thus there is no toxicity. Our work in the laboratory, and Mt. Sinai's Dr. Giulio Pasinetti's work in mice, suggest that administration of the compound to Alzheimer's patients might block the development of these toxic aggregates, prevent disease development and also ameliorate existing disease."
Human clinical trials are next.
"No disease-modifying treatments of Alzheimer's now exist, and initial clinical trials of a number of different candidate drugs have been disappointing," Teplow said. "So we believe that this is an important next step."