Some 30 years ago, researchers were shocked to learn that the diet in France, which was high in saturated fats, was actually associated with a low death rate from heart disease. The finding was call the French paradox. Conventional American medicine taught people that saturated fat causes heart attacks.
Since the French regularly enjoy wine, there’s been great interest among scientists that wine and grapes could explain the paradox.
This has led to the discovery of a number of bioactive compounds in grapes, with a variety of activities in the body. Thanks to these compounds, we now know grapes not only protect the heart, but the brain as well.
The latest findings were published in January. . .
For their study, researchers from the University of California enrolled five men and five women with mild cognitive impairment. Their average age was 72.
Half the group took a serving of grapes in the form of a freeze-dried powder mixed in water twice a day for six months. This was the equivalent of 2¼ cups of grapes per day – a pretty large amount, in my view.
The other half were given a powder that looked and tasted the same but lacked the polyphenols found in grapes.
The scientists took brain PET scans at the beginning and end of the study and observed changes in metabolism. The reason for focusing on metabolism is that lowered metabolic activity corresponds with early Alzheimer’s disease. Cognitive performance tests were also carried out.
Protects and Enhances Memory
For the placebo group, results showed significant metabolic decline in brain areas affected in early stage Alzheimer’s.
In contrast, those taking the grape powder showed no significant decline in metabolism, and in two brain regions they exhibited an increase which correlated with improvements in their attention and working memory, an effect not observed in the placebo group.
According to lead investigator Dr. Daniel Silverman, “The study examines the impact of grapes as a whole fruit versus isolated compounds and the results suggest that regular intake of grapes may provide a protective effect against early decline associated with Alzheimer’s disease.”
Note: These findings argue for eating whole foods, not just extracts or isolated compounds like resveratrol.
Dr. Silverman adds, “This pilot study contributes to the growing evidence that supports a beneficial role for grapes in neurologic and cardiovascular health….”
Wide-Ranging Brain Benefits
Pamela Mayer, senior staff scientist for the Salk Institute for Biological Sciences in La Jolla, California, explained the brain-healthy benefits of grapes in the book Grapes and Health published in 2016.
She writes that since there are so many regions of the brain that can fall prey to losses in function, treatments that have multiple biological activities and can focus on different targets in the brain could be the best therapeutic option. “Grapes provide one such treatment.”
Dr. Mayer explains that studies in both humans and animals show freeze-dried grape powder, grape seed extract and grape juice all positively impact brain function via reduced free radicals, improved signaling, lowered inflammation, better vascular function and less clumping of proteins.
If you prefer actual fresh grapes rather than a powder, juice or supplement, then red or purple varieties have the most polyphenols. But you will need to consume them regularly to benefit. In fact, you’d have to consume more than two cups a day, every day, to match the doses in the University of California study.
As senior consultant neurosurgeon Dr. Randhir Kumar puts it:
“Eating grapes once in while is not going to work. The trick is to adopt grapes in our daily diet and consume them consistently. Only then will there be long term neurological and cardiovascular benefits.”
- Grapes & Health ed. JM Pezzuto, Springer 2016