Polyphenols are plant-based dietary compounds with antioxidant and anti-inflammatory properties. These properties reduce the ongoing damage to the DNA in our cells. Polyphenols have, therefore, been the subject of intense research as potential prevention agents for a variety of human ailments, including cardiovascular disease, dementia, and cancer.

Rich sources of polyphenols are found naturally in most blue and red berries, grapes (including red wine), pomegranates, walnuts, peanuts, olive oil, green tea, dark chocolate and cocoa, coffee, and beer.

Follow up:

Recent animal research has suggested that polyphenols derived from grape seeds can reduce the development of plaques in the brain (at least in mice) that are associated with the development of Alzheimer’s disease. Now, a newly published clinical study suggests that Concord grape juice, which is rich in polyphenols, may be able to improve early memory decline in older adults.

In this small study, which has been published in the British Journal of Nutrition, 12 elderly adults with declining memory were divided into two groups. One was given Concord grape juice supplements daily for a period of 12 weeks. The second group received placebo supplements that were identical in appearance to Concord grape juice, but which contained no juice. Neither the 12 patient volunteers nor the research assistants were aware of which patients received grape juice and which patients received the placebo.

Tests of memory and other aspects of cognitive function were administered to all 12 patient volunteers. These tests revealed statistically significant improvements in verbal learning skills among the patients who received 12 weeks of Concord grape juice (when compared to the placebo group).

Although not statistically significant, improvements were also noted in both verbal and spatial recall among the patient volunteers who received the grape juice supplements in this small clinical study with a brief duration of patient follow-up.

While larger studies will be required to confirm these findings, the nature of this small study gives it considerably more predictive power than the larger dietary, survey-based epidemiological studies that are more commonly used in disease prevention research.
The evidence-based role of dietary polyphenols in cancer prevention is discussed in great detail in the soon to be guide to “A Cancer Prevention Guide for the Human Race.”