About Red Wine Extract
Red wine (grape skin) extract is a whole-matrix polyphenol concentrate from Vitis vinifera skins — anthocyanins, oligomeric proanthocyanidins, flavonols (quercetin, myricetin), phenolic acids, and a small amount of resveratrol/piceid. It is distinct from purified resveratrol (a single stilbene dosed far higher per the compound) and from grape SEED extract (seed-specific OPCs, no anthocyanins). Clinical evidence is thin and mixed. The cleanest trial of isolated red wine polyphenols (Botden 2012, Provinols 280–560 mg; PMID 22421906) found NO effect on peripheral or central blood pressure. A grape-wine polyphenol blend (Draijer 2015, ~550 mg red wine extract within an 800 mg blend; PMID 25942487) lowered 24h ambulatory BP by a modest ~3/2 mmHg but did NOT improve endothelial function (FMD). A small open-label, uncontrolled study (Kitada 2020, n=12; PMID 33053742) reported improved insulin sensitivity, lipids, and SIRT1 expression, but had no placebo group. Most retail 'wine extract' products are not standardized to a defined polyphenol or resveratrol content, so the actual delivered dose of any bioactive is unknown. Evidence rated low. No established RDA/UL.
What Red Wine Extract supports
- Mixed BP evidence: pure extract was null; a modest ~3/2 mmHg drop came only from a blend
- Polyphenol antioxidant activity, mostly mechanistic
How much Red Wine Extract to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
250–500
mg
Branded red wine polyphenol fractions (e.g. Provinols) were dosed around 250–300 mg/day in endothelial/BP trials; generic 'red wine extract' capsules run 200–500 mg. This is a whole-matrix polyphenol extract (anthocyanins, proanthocyanidins, flavonols, plus a small fraction of resveratrol), NOT purified resveratrol — do not score it against resveratrol's 150–500 mg trans-resveratrol range.
Clinical evidence
Limited clinical evidence. Whole-matrix grape-skin polyphenol extract, not purified resveratrol. BP evidence is mixed: pure red wine polyphenols were null (Botden 2012, PMID 22421906) while a grape-wine blend gave a modest ~3/2 mmHg drop with no FMD change (Draijer 2015, PMID 25942487). A small uncontrolled study found metabolic benefits (Kitada 2020, PMID 33053742). Generic products are rarely standardized — evidence rated low.
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