Resveratrol is a natural polyphenol, a type of compound found in various plants. Certain plants produce resveratrol as a protective response to environmental stressors like injury or attack from pathogens. This compound acts as a defense mechanism, helping the plant fight off harm and maintain its health.
Natural Sources of Resveratrol
Resveratrol is found in various foods, with the highest concentrations in the skins of red grapes. Because red wine fermentation includes the grape skins, it contains significantly more resveratrol than white wine, where the skins are removed. The amount in red wine varies depending on the grape variety and the fermentation process.
Beyond grapes and wine, resveratrol is also present in berries like blueberries, cranberries, and raspberries. Peanuts, dark chocolate, and cocoa are other sources. The concentration of resveratrol in these foods varies based on factors like the plant’s geographic origin and its exposure to stressors.
Biological Activity and Potential Health Effects
Interest in resveratrol stems from its biological activity, primarily its function as an antioxidant. Antioxidants help the body manage free radicals, which are molecules produced during metabolic processes that can cause cellular damage through oxidation. Resveratrol’s antioxidant properties help protect cells from this type of damage.
Beyond its antioxidant capacity, resveratrol has demonstrated anti-inflammatory effects in studies. Research suggests it may influence signaling pathways to inhibit substances that promote an inflammatory response. This action is being investigated for its role in protecting blood vessels and other tissues from inflammation-related damage.
A significant area of research revolves around resveratrol’s interaction with a family of proteins called sirtuins. Sirtuins are involved in regulating numerous cellular processes, including gene expression and metabolism. Resveratrol is known to be an activator of SIRT1, a specific sirtuin that has been linked to cellular health and longevity in preclinical studies. By activating SIRT1, resveratrol may influence pathways that help protect cells from stress and damage, including enhancing the body’s own antioxidant defenses.
These mechanisms are thought to be connected to resveratrol’s potential effects on cardiovascular health. Studies have explored its ability to promote the relaxation of blood vessels and inhibit factors that could lead to blockages. Its antioxidant and anti-inflammatory actions may also help protect the cardiovascular system from damage over time. While much of this research is promising, it is important to note that many studies have been conducted in laboratory settings or animal models, and human research is ongoing to fully understand these effects.
Resveratrol Supplementation and Considerations
Resveratrol is widely available as a dietary supplement, often in capsule or tablet form. These supplements typically contain extracts from the root of the Japanese knotweed plant (Polygonum cuspidatum), which is a rich source. When choosing a supplement, it is common to see trans-resveratrol specified on the label. This is one of the two main forms of the compound, and it is considered the more biologically active and stable form compared to cis-resveratrol.
The dosages used in human studies have varied widely, ranging from around 150 milligrams to over 1,500 mg per day. There is currently no established recommended daily intake for resveratrol. While doses up to 1,500 mg daily have been used for up to three months in some studies, higher amounts are more likely to cause side effects. It is important to recognize that supplements provide a much higher concentration of the compound than what can be obtained through food sources alone.
At higher doses, above 2.5 grams per day, resveratrol can cause gastrointestinal issues. Common side effects include nausea, diarrhea, and abdominal cramping. Because resveratrol may slow blood clotting, it could increase the risk of bleeding and bruising, especially for individuals with bleeding disorders or those taking anticoagulant or antiplatelet medications like blood thinners. It is recommended to stop taking resveratrol supplements at least two weeks before a scheduled surgery to minimize this risk.
The compound might also interact with how the body processes certain medications. It has the potential to affect enzymes in the liver that are responsible for breaking down many common drugs. Additionally, because resveratrol may have estrogen-like activity, individuals with hormone-sensitive conditions should be cautious. Consulting with a healthcare professional before starting supplementation is advisable to discuss appropriate dosage and potential interactions with existing medications or health conditions.