MONDAY, July 19, 2004 (HealthDayNews) -- Can staying trim, eating lots of leafy greens and maintaining healthy blood pressure and cholesterol levels -- all while doing a little gardening or concert-attending -- stave off Alzheimer's?
Increasingly, the evidence seems to suggest "yes."
Three studies presented Monday at the International Conference on Alzheimer's Disease and Related Disorders in Philadelphia, which runs from July 17 to 22, indicate that modifiable lifestyle factors such as physical activity and social networking can help reduce the risk of cognitive decline including Alzheimer's.
"This really represents the beginning of more research in this area," Marilyn Albert, chairwoman of the Alzheimer Association's Medical and Scientific Advisory Council, said at a news conference in Philadelphia on Monday.
"The Alzheimer's Association's ultimate goal is to prevent the disease entirely," added Albert, who is director of the division of cognitive neuroscience in the department of neurology at Johns Hopkins University School of Medicine. "Now is the time to think about risk."
"It seems like common sense, but there's some evidence that these are the important things to do," added Neil Buckholtz, chief of the Dementias of Aging Branch at the National Institute on Aging.
After following a group of nearly 1,500 elderly subjects for more than 20 years, researchers in Sweden and Finland found those who were obese in middle age were twice as likely to develop dementia when they were older. "Obese" was defined as a body mass index (BMI) of more than 30.
High cholesterol and high blood pressure each also increased the risk twofold. All three of these factors had an additive effect, increasing risk six times when they were all present in one person, said study author Dr. Miia Kivipelto, who is with the Karolinska Institute in Stockholm, Sweden.
Obesity, high cholesterol and high blood pressure are also risk factors for cardiovascular disease, and there is increasing evidence that dementia and cardiovascular problems are somehow linked. Not only can cardiovascular disease lead to certain types of dementia, it now seems plausible that separate factors such as cholesterol could contribute to Alzheimer's as well.
This is a good news-bad news scenario. While the prevalence of obesity is increasing globally, "BMI is easy to monitor so it represents as modifiable risk factor," Kivipelto said. "It seems possible that by reducing obesity, we can modify vascular risk factors and modify the risk for Alzheimer's disease."
Researchers at Harvard Medical School found women who ate cruciferous or other green, leafy vegetables in middle age had better cognitive abilities as they aged.
More than 13,000 women aged 70 to 81 who were part of the Nurse's Health Study filled out 116-item questionnaires on what foods they ate and how often.
Overall, there was no association between fruit and vegetable intake and cognitive decline. There was, however, an inverse association between green, leafy vegetables (such as romaine lettuce and spinach) and cruciferous vegetables (such as cabbage), both of which have high levels of antioxidants and folates.
Women who ate at least eight servings (half a cup each) per week were essentially 1.7 years younger in terms of cognitive aging compared to women who only ate three servings a week. Similarly, women who ate five servings a week of cruciferous were about 1.3 years "younger" in terms of cognition than those who ate only two servings, said study author Jae Hee Kang.
"We're talking really modest differences," Kang said. "But it could be a significant public health benefit."
While both of these studies looked at the effects of activities undertaken in middle age, a third study looked at the effects of activities undertaken in old age.
The study, led by Dr. Laura Fratiglioni, also of the Karolinska Institute, found that leisure activities that combine social, mental and physical components are the most likely to prevent dementia.
"Combination activities are important," Fratiglioni said. Such activities could include gardening, walking or taking a course.
While there are no answers to the big question of whether nature or nurture is more important in the onset of Alzheimer's, environment does seem to be taking a more prominent role. "Even subjects with a genetic predisposition [to Alzheimer's] can have modulation of genetic susceptibility," Fratiglioni speculated.
Kivipelto added that the risk associated with high blood pressure and high cholesterol was, in fact, higher than that associated with the apoE genes.
"The pathology for Alzheimer's disease develops over a very long period of time, 10 years or longer," Albert said. "If they are going to be concerned, they should start as early in life as possible, but certainly by middle age."
Visit the Alzheimer's Association's Maintain Your Brain site.