Resveratrol is a secondary plant substance and belongs to the family of polyphenols. This was demonstrated for the first time in 1963 in knotweed plants. It is now known that it is contained in other types of plants, such as in lilies, and also in foodstuffs, such as grapes and peanuts. The plant uses the resveratrol to stave off fungi, bacteria and environmental toxins. Since it forms the substance only when an infestation is imminent, the content varies considerably. Furthermore, the resveratrol content in the plant increases when UV radiation and ozone levels rise. Incidentally, the resveratrol contained in peanut butter is two to seven times higher than in the fresh, unprocessed peanut. In laboratory studies on protection against cardiovascular disease, resveratrol has been proven to be an antioxidant by virtue of the positive impact exerted on blood lipid levels, as well as its anti-inflammatory and anti-carcinogenic effect. Antioxidants protect the body against harmful metabolic products – so-called free radicals – which can arise, for instance, owing to stress, smoking and the consumption of alcohol. Results of human trials are not yet available.