Rodent study supports previous findings indicating a protective effect from berry antioxidants
by Craig Weatherby
Berries display brain-enhancing and -protecting potential in a growing number of test tube and animal studies.
(See “Strawberries Seen to Enhance Long-Term Memory,” “Berries May Offer Brain Benefits to Astronauts and Earthbound Alike,” and “Berries Seen Reducing Brain Damage from Strokes.”)
The results of an investigation in rodents provides further proof of the brain-boosting promise of colorful berries … in this case, blue fruits.
Researchers from the National Institute on Aging, Tufts University, and Louisiana State University conducted their study in rats over an eight-week period:
The scientists then injected a chemical called kainic acid into the rats’ hippocampus, which is a brain center of memory and learning. Kainic acid generates cell-damaging free radicals and replicates the kind of brain-cell losses seen in people suffering from Alzheimer’s and related diseases.
- Group 1 was fed rat chow containing two percent blueberry extract.
- Group 2 (control group) received the same rat chow without blueberry extract.
The researchers then subjected the animals to maze tests to see whether their brain functions showed any differences, and later examined their brains.
Compared with the control group fed blueberry-free chow, the rats fed a chow that included blueberry extract showed enhanced performance in the maze test, they lost significantly fewer brain cells, and they retained more viable brain cells.
As the researchers wrote, “These findings suggest that blueberry supplementation may protect against neurodegeneration and cognitive impairment... a blueberry enriched diet provided significant protection…”
Although the causes and processes of Alzheimer’s remain uncertain, it is characterized by a build-up of plaque from beta-amyloid protein deposits, which are associated with an increase in brain cell damage and death from oxidative stress.
Previous studies indicate that the colorful polyphenol-type antioxidant pigments in berries protect against oxidative stress.
However, the NIH-Tufts team believe that the benefits of blueberries may extend beyond their antioxidant powers: “…at least part of the efficacy of the blueberry supplementation may be to enhance neuronal [nerve cell] signaling… This would allow more effective intra- and inter-area communication and ultimately facilitate both cognitive and motor function.”
More research is needed, but these results reinforce the idea that fruits and other foods rich in polyphenol-type antioxidants
—like berries, tea, and cocoa
—could help prevent and treat Alzheimer's disease and related brain disorders.
- Duffy KB, Spangler EL, Devan BD, Guo Z, Bowker JL, Janas AM, Hagepanos A, Minor RK, Decabo R, Mouton PR, Shukitt-Hale B, Joseph JA, Ingram DK. A blueberry-enriched diet provides cellular protection against oxidative stress and reduces a kainate-induced learning impairment in rats. Neurobiol Aging. 2007 May 22; [Epub ahead of print]