What is Resveratrol?
Trans-Resveratrol (Resveratrol) is a powerful antioxidant polyphenol produced naturally in certain plants which protects them from environmental stresses and injuries (e.g., those caused by fungus, bacteria, viruses, insects, direct sunlight and humidity, etc.). Accordingly, resveratrol is also found in the fruits growing from these plants including grapes, blueberries, raspberries, cranberries, mulberries, cocoa beans, and peanuts.
From a chemical standpoint, resveratrol is a small molecule with the following structure: C14H12O3. Resveratrol’s low molecular weight (228.247 g/mol) makes it a good candidate to penetrate cell membranes, thereby reach intracellular sites of action. Accordingly it is not surprising that resveratrol can pass through the human blood brain barrier.
As noted above, Resveratrol is found naturally in fruits and consequently the food and drinks made from them. For its part, red wine contains relatively large amounts of Resveratrol (5 mg. per 750 ml bottle), which is extracted during the fermentation process (red wine, as opposed to white wine, is often fermented on the skins of grapes for multiple weeks. The skins contain relatively large amounts of resveratrol because the resveratrol is produced to protect the berries from environmental stresses).
Resveratrol can also found in varying amounts in dietary supplements. While many supplements are made entirely of resveratrol, other supplements contain additional ingredients (for instance, pterostilbene (an analogue of resveratrol), quercetin, grape seed extract, green tea extract). In addition, the purity of the resveratrol found in these supplements can vary depending on the method and source of resveratrol production. For instance, supplements are available which contain 98 to 99% pure Resveratrol (which is a white/off-white in color) while other supplements contain 50% or less pure resveratrol (which can be brownish in color). The respective supplement label will often tell you the purity of the resveratrol in the product.
As a general rule, supplements that contain purer resveratrol are more expensive than supplements with less pure resveratrol (this is because either extra steps must be taken to produce a purer product or manufacturing intellectual property is involved).
Most resveratrol supplements are made from a plant native to Asia called Polygonum Cuspidatum (e.g., Japanese Knotweed). An increasing amount of resveratrol supplements are being made from yeast fermentation, whereby yeast are programmed to produce pure or very nearly pure resveratrol (similar to the way yeast can turn sugar into alcohol when making wine, beer or spirits).