Dai Q, Borenstein AR, Wu Y, et al: Fruit and vegetable juices and Alzheimer’s disease: The Kame Project. Am J Med. 2006;119:751-759.
Background. Hydrogen peroxide is thought to play a role in the B-amyloid peptide-mediated oxidative damage associated with Alzheimer’s disease. The dietary antioxidants known as polyphenols have a greater neuroprotective effect against hydrogen peroxide than do antioxidant vitamins. Fruit and vegetable juices are rich in polyphenols. The relationship between fruit and vegetable juice consumption and Alzheimer’s disease risk was investigated in a Japanese-American population.
Methods. The population-based cohort study included 1,836 Japanese-Americans living in King County, Washington. The subjects—aged 65 years or older and free of dementia at baseline in 1992-94—were followed up through 2001 for the occurrence of Alzheimer’s disease. The investigators hypothesized that high consumption of fruit and vegetable juices would delay the onset of Alzheimer’s disease.
Results. High consumption of fruits and vegetable juices was associated with a reduced risk of Alzheimer’s disease, after adjustment for possible confounding factors. For subjects who drank fruit and vegetable juices at least three times weekly, the hazard ratio for probable Alzheimer’s disease was 0.24, compared to those who drank juice less than once weekly. For those who consumed fruit and vegetable juice 1 to 2 times per week, the hazard ratio was 0.84. The protective effect of juice consumption appeared greater for subjects who carried the apolipoprotein E_-4 allele and for those with low levels of physical activity. Alzheimer’s disease risk was unrelated to intake of vitamin C or E, _-carotene, or tea.
Conclusions. High consumption of fruit and vegetable juices may be associated with a delayed onset of Alzheimer’s disease. This protective effect appears greatest among elderly subjects at high risk. The findings may lead to new approaches to the prevention of Alzheimer’s disease.
Commentary: In this large epidemiologic study, the authors found that regular consumption of fruit and vegetable juice (at least every other day) delayed the onset of Alzheimer’s disease, particularly in those at high risk for the disease. Subjects who reported drinking juices at least three times a week had a 76% reduction in the risk of developing signs of Alzheimer’s disease. This may be related to the non-vitamin antioxidant polyphenols that are concentrated in the skins and peels of fruits and vegetables.
Copyright 2007, EXPLORE: The Journal of Science and Healing
Reprinted with permission.