Eating two helpings of grapes a day for a month has been found to increase microbiome diversity and to reduce bile acid production by 40% and cholesterol by 6.1%.
Grapes contain a variety of healthy compounds like good levels of fibre and the polyphenols resveratrol, grape seed extract and others.
A study from the Center for Human Nutrition, David Geffen School of Medicine in LA, took 46 gm of whole grape powder (it’s more scientific than feeding people two ‘helpings’ of California grapes) and gave it to adults daily. First, everybody went on a low polyphenol diet for a month. Then, the second month included the whole grape powder.
The scientists looked at the effects on the gut microbiome and on blood fats.
At the end of the second month the diversity of the gut microbiome had increased significantly. The family Verrucomicrobia increased, as did the bacteria Akkermansia, Flavonifractor and Lachnospiraceae. However, there was an overall decrease in the families Bifidobacterium and Dialister.
Blood triglyceride levels and body composition were not changed by grape powder consumption.
However, grape powder consumption significantly decreased the total cholesterol by 6.1%, with a decrease in LDL cholesterol by 5.9% and total bile acid by 40.9%.
Surprisingly, HDL cholesterol fell by 7.6%.
Jieping Yang, PhD was the lead author and her team have previously shown grapes to have antibacterial and antiviral benefits. This research added a gut microbiome diversity and a cholesterol lowering benefit, suggesting strong benefits for heart health.
In a 2009 pilot study, grapes were shown to have a regulatory effect on colorectal cancer gene expression in individuals who consumed them for two weeks.
Also in 2009, Boston Medical School researchers reviewed the existing data and suggested the consumption of grapes would reduce cardiovascular disease.
By 2017, researchers from the Hershey Cancer Institute at Penn State had put the two bioactive compounds in grapes – resveratrol and grape seed extract – together and showed they had a significant effect against cancer stem cells and an equally strong effect against colorectal cancer.
Go to: Grape compounds suppress Colorectal Cancer
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References
- Effect of Standardized Grape Powder Consumption on the Gut Microbiome of Healthy Subjects: A Pilot Study; Jieping Yang et al; Nutrients 2021, 13(11), 3965; https://doi.org/10.3390/nu13113965
- Grapes and Cardiovascular Disease; Mustali M Dohadwala and Joseph Vita; J Nutr 2009, Sept 139(9)
