Fruit and vegetable juice may ward off Alzheimer's

NEW YORK (Reuters Health) - Drinking fruit and vegetable juices frequently could help stave of Alzheimer's disease in individuals at risk for developing the disease, research suggests.

There is evidence from both lab and animal studies that high levels of reactive oxygen species (ROS) -- harmful byproducts of normal metabolism -- may be involved in the development of Alzheimer's disease.

While vitamins and polyphenols contained in plant foods exert antioxidant effects and thus blunt the action of ROS, certain ways of preparing these foods can deplete their nutrient content. Juicing, however, can preserve much of the antioxidant content of fruits and vegetables.

In their study, Dr. Qui Dai of the Vanderbilt University in Nashville, Tennessee and colleagues looked for links between fruit and vegetable juice consumption and Alzheimer's risk. They analyzed juice consumption in 1,836 Japanese-Americans living in Washington State who had no dementia when the study began, in 1992-1994, and were followed until 2001.

They found that people who drank juices at least three times a week had one-quarter the risk of developing dementia compared to those who consumed juice less than once a week. The effect was stronger in people carrying an Alzheimer's-associated gene variant and in those who were not physically active.

The effects of antioxidant vitamins alone aren't enough to explain the findings, Dai and colleagues note, and further research is needed to determine whether polyphenols might also have protective effects.

More study is also needed to determine which fruit and vegetable juices are most beneficial and how long they must be consumed, they add.

"These results may lead to a new avenue of inquiry in the prevention of Alzheimer's disease," the researchers conclude.

SOURCE: The American Journal of Medicine, September 2006.

Source Reuters