Uncertainties prevail over human health benefits of polyphenols

Despite scores of studies documenting the effects of healthful plant nutrients called polyphenols in protecting nerves from damage, it would be "unwise" to assume that the same protective effects occur for Alzheimer's disease (AD) and other human disorders, a new report concludes. It is scheduled for the July 9 issue of ACS' bi-weekly Journal of Agricultural and Food Chemistry.

In the report, Charles Ramassamy and colleagues in Canada analyzed the results of more than 200 laboratory and animal studies on these materials, found in fruits, vegetables, wine, chocolate, coffee, tea, and other foods. They found abundant evidence that polyphenols do, indeed, protect nerves from the kind of damage that occurs in AD and other chronic brain disorders.

The researchers concluded, however, that "it is not at all clear whether these compounds reach the brain in sufficient concentrations and in a biologically active form to exert beneficial effects." Resolving those uncertainties will take years of additional research, they say in the report, which includes a list of the 50 foods containing the highest amounts of polyphenols.

Source: ACS