Obesity, diet, inactivity linked to dementia risk


Cardiovascular risk factors may speed cognitive decline as we age. Green vegetables and diverse leisure activities may help us maintain our brains.

PHILADELPHIA, July 19, 2004 -- Cardiovascular disease risk factors such as midlife obesity, high cholesterol, and high blood pressure also appear to speed cognitive decline later in life, according to research reported today at The 9th International Conference on Alzheimer's Disease and Related Disorders (ICAD) in Philadelphia, presented by the Alzheimer's Association.

According to another study, eating vegetables like spinach and broccoli may slow cognitive decline. Activities ranging from cultural or political events to doing handicrafts were also found to promote brain health during aging.

"These three studies add to the growing understanding that we may be able to reduce our risk of Alzheimer's by changing our lifestyles losing weight, changing our diets, and staying mentally and socially active. What is needed now are more, and more extensive, research studies of lifestyle changes that might help prevent Alzheimer's," said Marilyn Albert, Ph.D., chair of the Alzheimer Association's Medical and Scientific Advisory Council.

Risk Factors For Cardiovascular Disease Also May Lead to Dementia

The same factors that put us at risk for heart attacks may lead to dementia, according to a long-term study of middle-aged and elderly Finns. The evidence for a link between cardiovascular disease and dementia has become stronger in recent years. While cardiovascular disease can lead to vascular dementia by restricting blood flow to the brain, scientists also suspect that individual components of cardiovascular disease such as high cholesterol or hypertension could accelerate the Alzheimer's disease process.

At ICAD, Miia Kivipelto, M.D., Ph.D., of the Karolinska Institute in Stockholm, and collaborators in Sweden and Finland presented data from a group of nearly 1,500 elderly subjects, followed for an average of 21 years. The researchers found that study participants who were obese in middle age for example, weighing more than 197 pounds at a height of 5 feet, 8 inches were twice as likely to develop dementia later in life. For those subjects who also had high cholesterol and hypertension in middle age, the risk of dementia was multiplied six times.

"More and more research is pointing to common causes for cardiovascular disease and dementia," Albert said. "This study should make physicians and policy makers take notice that they can make significant contributions to healthy aging in several areas by encouraging people to eat healthful foods and exercise more."

Vegetables Linked to Better Brain Health

Researchers report that women who ate green leafy or cruciferous vegetables in middle age preserved more of their cognitive abilities as they entered their 70s.

"Diets rich in fruits and vegetables decrease cardiovascular disease, perhaps due to nutrients such as antioxidants and folate," said author Jae Hee Kang, Sc.D., of Harvard Medical School. Kang and colleagues evaluated participants in the Nurses Health Study, which has been following the diets and health status of more than 13,000 women since 1972. The researchers calculated the women's intake of fruits and vegetables between 1984 and 1995 and correlated these values with performance on tests of cognitive function conducted between 1995 and 2003, when the women were in their 70s.

Increased consumption of fruits and vegetables, overall, did not affect the overall decline in cognitive scores, whether due to aging or any forms of dementia. However, the researchers found that women with the highest consumption of green leafy vegetables and cruciferous vegetables both high in folate and antioxidants such as carotenoids and vitamin C declined less than women who ate little of these vegetables.

"This difference can be approximated as being one to two years younger in terms of cognitive aging," said Kang. "Although this difference may be modest, if confirmed by other studies it may have a large impact in reducing the public health burden of dementia."

Complex Leisure Activities Protect Elderly Against Dementia

Another study presented at ICAD suggests that leisure activities combining social, mental, and physical activity are the most likely to prevent dementia. Laura Fratiglioni, M.D., Ph.D., and doctoral student Anita Karp, of the Karolinska Institute in Stockholm and colleagues assessed the relative contributions of mental, social, and physical activity to cognitive health by assigning component scores to individual activities.

For example, visiting a summer cottage scores 2 on the physical scale, 2 for mental, and 2 for social activity, whereas political or cultural activities score 1 for physical, 3 for mental, and 3 for social activity. Total mental, social, and physical scores were calculated for each participant.

The researchers studied a group of nearly 800 men and women, aged 75 years and over, from the Kungsholmen Project aging study. They correlated the number of dementia cases that developed over a three-year period with activity scores from approximately six years earlier. Fratiglioni and her colleagues found that older people with higher mental, physical, or social component scores all had a lower risk of developing dementia even after controlling for age, sex, education, morbidity, physical and cognitive function. However, the greatest effect was seen in people with high scores in all or in two of the components.

"These findings suggest that a broad spectrum of activities, involving more than one of the components, is more beneficial," said Fratiglioni. "In old age, even light physical activities such as walking or gardening are beneficial. And the physical components in, for example, housekeeping or going to educational courses, theatre, and concerts can be added up."

Alzheimer's Association Says "Maintain Your Brain"

The Alzheimer's Association believes it is important for Americans to understand that healthy aging is a process that should begin sooner in life rather than later in order to remain healthy of body and mind for as long as possible.

"More research is necessary, especially in the form of prevention trials, but there is increasing evidence that healthy lifestyle habits Americans are familiar with today such as managing your numbers your blood pressure, cholesterol, and blood sugar levels, as well as your body weight contribute to healthier aging and may also decrease your risk for Alzheimer's," Albert said.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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