Certain polyphenols abundant in fruit and vegetable juices may play an important role in delaying the onset of Alzheimer's disease, reports Dominique Patton.
The research was presented at the US-based Alzheimer's Association's first conference on prevention of dementia, running in Washington this week (abstract 05-A-103-ALZ-PC).
The Florida researchers studied more than 1,800 older Japanese American men and women from the Kame Project in Seattle, in which participants were dementia-free at the onset of the study and were followed for up to nine years.
Dietary consumption was determined using a food frequency questionnaire given at the beginning of the study that provided information on intake of fruits, vegetables, tea, wine, and fruit and vegetable juices.
The accumulation of reactive oxygen species in the brain are thought to exhaust antioxidant capacity and lead to the onset or progression of Alzheimer's.
Antioxidant vitamins, particularly vitamin E from dietary fruits and vegetables, has been associated with delayed onset of the disease, although there is little evidence to date that supplements can offer the same benefit.
But animal studies have found that a number of polyphenols from juices have stronger protection for neuronal cells against oxidation than vitamins E and C.