Physical Activity, APOE Genotype, and Dementia Risk: Findings from the Cardiovascular Health Cognition Study.
L Powdewils et al., American Journal of Epidemiology 161:639-651, 2005
Participating in regular physical activity reduced the risk of Alzheimer’s disease, vascular dementia, and other dementias in almost 3,400 American men and women over the age of 65 years who participated in the large cardiovascular health cognition study conducted between 1992-2000. Additionally, the study concluded that physical activity enhances heart and blood vessel health and overall quality of life.
“Use It or Lose It - Do Effortful Mental Activities Protect against Dementia?
J. Coyle. New England Journal of Medicine 348:2489-2490, 2003
In commenting on a major study published in the same issue, Dr Coyle wrote, “…..the study by Verghese et al. in this issue of the Journal (pages 2508–2516), … suggests that participation in cognitively demanding leisure activities in late life may provide protection against dementia.” He correctly points out that considerably longer and more complex research needs to be done to completely understand how genetic and lifestyle factors contribute to the risk for or protection from Alzheimer’s disease and other cognitive disorders associated with aging. He concludes his editorial with the recommendation that “…seniors should be encouraged to read, play board games, and go ballroom dancing, because these activities, at the very least, enhance their quality of life, and they just might do more than that.” In other words, reducing the risk of Alzheimer’s disease!
Physical Activity, Including Walking, and Cognitive Function in Older Women.
J. Weuve et al; Journal of the American Medical Association. 292:1454-146, 2004.
The Nurses Health Study began in 1976 and this report evaluated more than 18,766 US women aged 70-81 years as to the benefits on cognitive function from regular long-term physical activity. Women who walked at a modest pace for a total of 1.5 hours or more per week had better mental functioning and showed less age-related decline than did women who exercised less. This study gives meaning to the phrase “Walk the talk.”
Walking and Dementia in Physically Capable Elderly Men.
R. Abbott, et al. Journal of the American Medical Association. 292:1447-1453, 2004.
2257 physically capable men aged 71 to 93 years were followed in the Honolulu-Asia Aging Study. Like similar findings in women this study documented that walking is associated with a reduced risk of dementia in men. The greatest benefit was seen in men who walked farthest – 2 miles or more each day. “Promoting active lifestyles in physically capable men could help late-life cognitive function.”
Diet and the Risk for Alzheimer’s Disease.
Editorial. Annals of Neurology, 59:877-879, June 2006. Claudia H. Kawas, MD, Institute for Brain Aging and Dementia, University of California, Irvine.
Dr. Kawas reviews some of the scientific data about the Mediterranean diet. She concludes that the most recent study by Dr. Scarmeas and co-investigators is consistent with others that demonstrate better cognitive performance and a reduced risk of Alzheimer’s disease in persons who consume significant amounts of fruits, vegetables, fish, olive oil, and modest amounts of wine on a regular basis.
Mediterranean Diet and Risk for Alzheimer’s Disease.
N. Scarmeas, et al. Annals of Neurology 59:912-921, June 2006.
This landmark study by investigators at Columbia University Medical Center in New York followed more than 2,200 individuals for the development of Alzheimer’s disease for an average of 4 years. The results suggested a dose-response relationship: those who had the highest adherence to the Mediterranean diet had a reduced risk of Alzheimer’s disease of 40%, whereas those more modestly adhering to this diet had a risk reduction of about 20%. The beneficial effect of this diet is probably due to the complex nutritional components contained in the foods rather than any individual component. Perhaps most important are “fish, fruits, and vegetables rich in antioxidants such as vitamin C, vitamin E, and flavanoids, and higher intake of unsaturated fatty acids.” Importantly, this study, conducted in a multiethnic population in New York, and other published studies strongly indicate that following such a nutritional diet is beneficial not only to Mediterranean populations, but also to Northern European, Australian, Indian, and other populations.
Mediterranean Diet, Lifestyle Factors, and 10-Year Mortality in Elderly European Men and Women: The HALE Project.
K.T. B. Knoops, et al. Journal of the American Medical Association. 2004;292:1433-1439.
This study followed older individuals for 10 years and found that nonsmokers who ate a Mediterranean diet and exercised at least 30 minutes a day died from coronary heart disease, vascular disease such as stroke, and cancer at less than 50% the rate of those who did not follow this lifestyle. These behaviors lead to a low-risk lifestyle for adults.
Diet, Lifestyle, and Longevity—The Next Steps?
E. Rimm and M. Stampfer, Journal of the American Medical Association. 292;1490-1492, September 2004
In an editorial accompanying the article by Knoop et al., Drs. Rimm and Stampfer conclude: “Although understanding of the relation of lifestyle and health outcomes will continue to be refined, information available now is sufficient to take action. Knoop et al have identified a simple set of lifestyle practices that can reduce the mortality rate among elderly individuals by nearly two thirds. As a society, the United States spends billions on chronic disease treatments and interventions for risk factors. Although these are useful and important, a fraction of that investment to promote healthful lifestyles for primary prevention among individuals at all ages would yield greater benefit.”
Studies going back more than half a century document the benefits of a healthy lifestyle. Most impressive is the fact that when people move from a low-risk environment for heart disease such as Japan to a high-risk environment such as the U.S., their risk for diseases quickly rises. This is best explained by the change in diet and decrease in exercise. There are ample reasons to suggest that the same change in risk holds true for Alzheimer’s disease and other lifestyle-related diseases.
An active and socially integrated lifestyle in late life might protect against dementia.
L. Fratiglioni et al. Lancet Neurology 3: 343–53, 2004
This major review of research over the past 30 years concluded that three lifestyle components protect against dementia and Alzheimer’s disease: staying active with family and friends in a variety of social situations; using the brain by doing mentally stimulating activities; and getting regular physical exercise in any number of activities such as walking, swimming, working in the garden, etc.
Dietary Intake of Antioxidants and the Risk of Alzheimer Disease.
M. Engelhart et al. Journal of the American Medical Association. 287; 3223-3239, 2002
This is one of two major population-based studies that appeared in the same issue of JAMA in 2002. Dr. Engelhart and colleagues followed 5,395 Dutch men and women who were at least 55 years old and free of dementia at the outset of the study. They were followed for six years on average and during this period had reliable dietary assessments. A lower risk of Alzheimer’s disease was observed in participants who had a higher intake of vitamins C and E in their food. This reduced risk of Alzheimer’s disease was not present in those whose higher vitamin C and E intake came from supplements.
Dietary Intake of Antioxidant Nutrients and the Risk of Incident Alzheimer Disease in a Biracial Community Study.
M. Morris et al., Journal of the American Medical Association. 287:3230-3237, 2002.
This study followed 815 Chicago residents for an average of almost 4 years. Participants included black and white men and women, aged 65 years and older. Like its companion study in Holland, those individuals consuming higher amounts of vitamin E in their food and not in supplements alone had a reduced risk of both cognitive decline and Alzheimer’s disease.
Dietary Intake of Antioxidants and Risk of Alzheimer Disease - Food for Thought.
D. Foley, L. White. Journal of the American Medical Association. 287:3261-3263, 2002
Drs. Foley and White in this editorial accompanying the two JAMA articles mentioned above note that the current estimate of 360,000 new cases of AD each year in the USA is expected to increase to about 1,400,000 new cases per year within 40 years as more and more people live beyond the age of 80. They point out that, “Even modestly effective interventions that delay the onset of AD by 1 to 3 years will substantially alleviate the growing economic and societal burden associated with this disease.” They conclude that “… the idea that vitamin E and vitamin C might have beneficial effects on the underlying AD process makes sense, and it seems unlikely that antioxidant-rich foods would negatively affect brain aging. We continue to hope that when the final answer is established, it will be that the development of AD can be delayed or prevented by dietary intake.”
Aerobic Fitness Reduces Brain Tissue Loss in Aging Humans.
S. Colcombe et al. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 58:M176-M180, 2003.
Magnetic resonance imaging (MRI) is a powerful brain-imaging technique. This study used MRI and was consistent with earlier studies that aging brings with it a loss of both gray and white matter in multiple areas of the brain, especially in areas associated with cognitive functions. The major advance in this study was the demonstration that cardiovascular fitness protected against the loss of some of this brain tissue. The areas most protected by aerobic fitness are those that play central roles in successful everyday functioning.The investigators state that their results “also directly bear on issues of public policy and clinical recommendations in that they suggest a rather simple and inexpensive mechanism to ward off the effects of senescence on human brain tissue.”
Fitness Effect on the Cognitive Function of Older Adults: A Meta-Analytic Study.
S. Colcombe, A. Kramer. Psychological Science. 14:125-130, 2003.
Meta-analyses allow for scientifically valid conclusions by summarizing findings from different studies. Drs. Colcombe and Kramer incorporated the findings from 18 previously published studies that investigated the effects of physical fitness training on memory and thinking involving complex cognitive activities such as coordination, inhibition, scheduling, planning, and working memory in people ages 55-80 years old.
They asked the question “whether aerobic fitness training can have a robust and beneficial influence on the cognition of sedentary older adults.” And they concluded: “The answer provided by the present analysis is an unequivocal yes.” They found that aerobic fitness training improved mental performance across the board; it made little difference which form of physical training method was used, what the cognitive task was, or whether the participants were 55-65, 66-70, or older than 71 years. All benefited from the exercise.
Importantly, they concluded that exercise periods of less than 30 minutes did not result in significant cognitive benefit, but intermediate length sessions (31-45 minutes) were as beneficial as longer sessions (46-60 minutes). Also, even brief duration training programs (1-3 months) provided some benefit, but the best programs lasted more than 6 months.