Fruit, vegetables better cognitive performance

A German study published in the August issue of the Journal of Alzheimer's Disease has linked high intake of fruit and vegetables to better plasma antioxidant status and better cognitive performance.

The study of 193 healthy people aged 45 to 102 shows that individuals who had higher daily intake of fruits and vegetables had higher cognitive performance and higher levels of antioxidants in their blood.

The study was conducted by Dr. M. Cristina Polidori, at the Department of Geriatrics, Marienhospital Herne, Ruhr-University of Bochum, Germany along with colleagues at with the Department of Pharmacology at Temple University in Philadelphia, Pennsylvania and the Department of Geriatrics at Perugia University, Italy.

"It is known that there is a strong association between fruit and vegetable intake and the natural antioxidant defenses of the body against free radicals, and It is also known that bad nutritional habits increase the risk of developing cognitive impairment with and without dementia," Polidori said.

Cognitive impairment is found in people was Alzheimer's disease, which affects four million Americans. There is no cure for the disease.

Another early study published in the Sept. 2009 issue of Journal of Nutrition suggests that greater intake of high antioxidant foods such as berries, Concord grapes, and walnuts may increase health span and enhance cognitive and motor function in aging.

The study was conducted by J.A. Joseph and colleagues from the USDA-Agriculture Research Service at Tufts University in Boston Massachusetts.

Numerous studies have indicated that people eating a diet containi high amounts of fruits and vegetables exhibit fewer age-related diseases such as Alzheimer's disease, according to the authors.

Joseph and colleagues also found that blueberry or Concord grape juice supplementation in humans with mild cognitive impairment could increase verbal memory performance.

They explained that dietary supplementation with fruit and vegetable extracts high in antioxidants can lower the oxidative stress in aging and also enhance neuronal communication via increases in neuronal signaling and decreases in stress signals induced by oxidative/inflammatory stressors.

Another similar study published in the Sept 2006 issue of American Journal of Medicine suggests that many polyphenols in fruit and vegetables possess stronger neuroprotection against hydrogen peroxide than antioxidant vitamins.

In the study of 1836 Japanese Americans in King County Washington, Dai Q and colleagues from Vanderbilt School of Medicine found those who drank fruit and vegetable juices at least 3 times per week cuts their risk for Alzheimer's disease by 76 percent and those who drank juices once or twice a week lowered their risk by 16 percent.

The inverse association was more significant among those carried an apolipoprotein Eepsilon-4 allele and those who were not physically active.

On the other hand, they did not find any association between dietary intake of vitamin E, C or beta-carotene or tea consumption and risk of Alzheimer's disease.

By David Liu davidl at foodconsumer dot org