Category Archives: Scientific Studies

Science behind Proflavanol C100

Be sure to read What is Proflavanol C100 for more information on this unique product.

There is a difference in the quality of grape seed extracts

by Russ Barton, USANA Health and Science Education

Over the years I have been asked many times what makes our grape seed extract better, or how we know ours is top quality. First of all, we literally analyzed nearly all available grape seed extracts on the market and found that only a couple were consistent and high quality, and far exceeded the quality of the other extracts available at that time. But, in addition to the initial chemical analysis, we have conducted other studies in humans showing results from taking our formulation. Some of these studies have been somewhat groundbreaking. So, when you see all the different grape seed extracts available on the market and wonder what sets them apart, be confident that we know the difference because we’ve tested it repeatedly. We don’t just buy the best priced one from a random supplier. Here is a study published in the FASEB Journal showing that ingestion of our grape seed extract results in increased blood levels of important compounds. The first 4 authors are USANA scientists, in collaboration with Boston University School of Medicine.


Diets that are rich in plant foods have been associated with a decreased risk for specific disease processes and certain chronic diseases. In addition to essential macronutrients and micronutrients, the flavonoids in a variety of plant foods may have health-enhancing properties. Grape Seed Extract (GSE) is a common supplement that is known to be rich in the flavan-3-ol epicatechin and procyanidin oligomers. However, the bioavailability and the biological effects of the grape seed extract flavonoids are poorly understood. To begin to address these issues, we developed a method based on LC-MS detection to determine the physiological levels of epicatechin and catechin. This method allows for the determination of epicatechin in plasma at concentrations as low as 1 ng/mL.

We next evaluated the absorption of epicatechin, from 1-g grape seed extract taken orally in capsule form. By 2 h after ingestion, plasma epicatechin increased from an undetectable amount to 172 ng/ml (P, 0.001). Consistent with the antioxidant properties of epicatechin, within three hours, there was a significant 25% increase in plasma antioxidant reserve (P, 0.05). The data support the concept that the consumption of grape seed extract can result in significant increases in plasma epicatechin concentrations as well as an increase in plasma antioxidant reserve.