Grape Seed Extracts today are essentially industrial derivatives from grape seeds that have a strong concentration of vitamin E, flavonoids, linoleic acid, and phenolic compounds known as Oligomeric proanthocyanidins (OPCs).
These OPCs are what are normally touted as the powerful antioxidants of the bunch. They are found in the highest concentrations in grape seeds as well as lower concentrations in grape skin, grape juice, and wine.
The flavonoids and polyphenols within seem to be the compounds that are the most active and cause effects. They both primarily work as antioxidants. They are able to scavenge free radicals and remove many different types of chemicals and compounds from the body.
This supplement is believed to have a range of benefits related to the heart and other organs. Part of this involves lowering the LDL or “bad” cholesterol levels. It is also considered to be a protector against bacterial infections like staphylococcus, saving many different organs from a number of infections.
In studies, Resveratrol has been seen to have anti-cancer, anti-inflammatory, and antioxidant effects, as well as stabilizing blood sugar levels and improving cardiovascular function.
Side Effects & Dosages
There are no commonly reported side effects of this supplement with the possible exception of mild stomach discomfort. It is very safe and generally well-tolerated. Grapes and grape skin extracts have Generally Recognized As Safe status (GRAS) for use in foods in the USA.
The only two groups of people who are advised to avoid taking Grape Seed Extract are pregnant and nursing women (due to a lack of research on use in these groups at the moment) and those who are also using blood thinning medications (e.g. warfarin).
Grape Seed Extracts come in tablets, capsules, and even liquid extracts. You want to find those standardized to between 40 and 80 percent proanthocyanidins and/or an OPC content of not less than 95 percent.
There is no generally accepted standard dose, particularly since each formulation has a different mix of Grape Seeds and Extracts. Some are heavier on the OPC’s than others. Doses between 50 and 900 mg have been commonly reported.
The University of Maryland Medical Center suggests taking between 25 and 150 mg daily for general anti-oxidant support and 150 to 300 mg per day for chronic venous insufficiency.