Drinking juice linked with lower Alzheimer's risk

The September, 2006 issue of The American Journal of Medicine published the finding of Qi Dai, MD, PhD and colleagues that people who drank three or more servings of juice per week had a reduced risk of developing Alzheimer's disease compared to those who consumed juice less than once per week.

Participants were enrolled in the Ni-Hon-Sea Project, which investigated dementia in older individuals of Japanese ethnicity living in Hawaii, Seattle and Japan. The current study involved 1,836 Seattle subjects without dementia who were assessed for cognitive function every two years for up to ten years. Self-administered questionnaires were used to determine fruit and vegetable juice intake.

Adjusted analysis revealed that participants who reported drinking juice at least three times per week had a 76 percent reduction in the risk of developing signs of Alzheimer's disease compared to those who consumed less than one serving per week. The relationship was especially strong among individuals who carried a genetic marker associated with late-onset Alzheimer's disease.

Although the incidence of Alzheimer's disease among Japanese residents is low, the rate is greater among people of Japanese ancestry living in the United States, suggesting that environmental factors such as diet could be involved. The researchers believe that the polyphenol content of juice could be responsible for the benefit observed in the current study. Recent animal studies have associated polyphenol intake with a delay in cognitive decline. "Also, animal studies and cell culture studies confirmed that some polyphenols from juices showed a stronger neuroprotective effect than antioxidant vitamins. So we are now looking at polyphenols," Dr Dai stated.

Future research conducted by Dr Dai will ascertain if high blood concentrations of polyphenols found in fruit and vegetable juices are protective against cognitive decline and Alzheimer's disease.