Resveratrol capsules are supplements containing the antioxidant known as resveratrol. Some studies have indicated possible health benefits from taking a resveratrol supplement. Most resveratrol capsules are derived from the plant known as Polygonum cuspidatum or Japanese knotweed. Resveratrol is also found to naturally occur in peanuts, red wine and some fruits such as blueberries.
One study performed on mice taking resveratrol supplements has indicated a positive effect on blood glucose and insulin levels. Some researchers believe that resveratrol may aid in preventing insulin resistance. More studies are needed to confirm that the results are applicable to humans and that the high intake of resveratrol is safe to consume.
Most people take resveratrol capsules to ensure that they get a sufficient intake of antioxidants. Many hundreds of bottles of red wine would need to be ingested to get the same dosage of antioxidants found in a resveratrol capsule. In addition, some people are allergic to or do not wish to consume the food items or alcohol that also contain antioxidants. Some people also believe that resveratrol capsules should be absorbed through the lining of the mouth rather than swallowed.
Studies on animals with short lifespans, such as fruit flies and worms, showed that these creatures lived longer after receiving resveratrol. One animal study was performed on obese mice that were fed a resveratrol nutritional supplement. The mice had an increased lifespan and better health than obese mice in a control group.
Other studies have suggested resveratrol may help in preventing Alzheimer's disease and certain cancers. It is not known whether these results are applicable to human beings, because sufficient human trials have not taken place. A substance that works for lab animals may not be successful in human trials. The supplement given to the animals is also usually standardized, pure resveratrol. Like many supplements, resveratrol capsules may sometimes have little or no active ingredient.
Issues have been raised regarding the safety of taking resveratrol capsules over a long period of time. Currently, the effects of long-term use of resveratrol are not known, though some people have reported unwanted reactions from consuming the capsules. It has also been suggested that there may be unknown effects from consuming a knotweed-derived supplement as well. In the absence of firm data, any individual taking resveratrol capsules should closely monitor his health for adverse reactions.