Probably the best known of antioxidants, resveratrol is almost revered for its potential at reducing the risks of a whole host of diseases. Hence the massive interest in the potential healing power of grape juice and resveratrol. But do the claims hold up under scrutiny?
Grape Juice And Resveratrol
Most people have probably heard of resveratrol these days. Famous as the antioxidant in red wine, resveratrol has been lauded for it’s potential as an anti-cancer agent, controlling blood sugar, and most lately, for its possible anti-aging effects. The excitement about resveratrol has everyone looking at ways to increase their consumption, which explains the surge of interest in red wines and grape juice, as resveratrol-rich foods.
Structurally, resveratrol is a polyphenol that belongs in a class of compounds known as phytoalexins, which are different than the flavanoids found in foods like cocoa and coffee antioxidants. Having said that, much like flavanoids, resveratrol is produced by plants in response to external threats. In the case of resveratrol, that threat
is thought to be fungii, which explains why grapes grown in cooler regions typically have higher amounts of resveratrol than those grown in warmer climates. In grapes, resveratrol is produced in self-defense, as an anti-fungal and natural insecticide, which means it is actually a mild toxin. Interestingly enough, in grapes, resveratrol is most highly concentrated in the skin of the fruit. This helps explain why red wine is an excellent source of resveratrol, and grape juice is typically not a good source of this antioxidant. Speaking of food sources of antioxidants, the following table highlights the resveratrol content of some foods.
As a preventative or treatment, the science is still unclear. Like most antioxidants, resveratrol has shown promise against a whole host of cancers – in a test tube. Unfortunately, studies have shown that resveratrol is rapidly and efficiently eliminated from the body within 4 hours of being consumed. Even when subjects were given a 5-gram dose, peak blood levels of resveratrol were still 2.5 times lower than test tube results required to achieve anti-cancer activity. To put that number in perspective, most resveratrol supplements contain 10-50 milligrams of resveratrol. There is some potential for using resveratrol as a topical agent for treating cancer, where it could be applied directly to the tumor cells. Early testing has shown some promise.
Resveratrol and red wines have also been linked to cardiovascular benefits. As a proven vasodilator, resveratrol has been shown to relax the blood vessels, and may play a role in raising HDL.
With the outcome still in question, its hard to weigh the potential benefits of consuming resveratrol against the potential risks associated with increased alcohol consumption. With that concern stated, another approach is to consume moderate amounts of red grape juice, and resveratrol will follow. The calories are still a concern, but if you understand that, even with supplements, you’ll never get to the quantities used in test tube evaluations, grape juice may be the best compromise.