Proanthocyanidins are a group of flavonoids found in pine bark, grape seed, and other plant sources that may increase the amount of ultraviolet rays necessary to cause sunburn.
Trials have tested combinations of several antioxidants. One preliminary study found that a daily combination of beta-carotene (6 mg), lycopene (6 mg), vitamin E (15 IU), and selenium for seven weeks protected against ultraviolet light. However, a double-blind trial of a combination of smaller amounts of several carotenoids, vitamins C and E, selenium, and proanthocyanidins did not find significant UV protection compared with placebo. Similarly, in a controlled trial, a combination of selenium, copper, and vitamins was found to be ineffective.
Proanthocyanidins (OPCs) are a group of flavonoids found in pine bark, grape seed, and other plant sources. In a preliminary trial, volunteers were supplemented with Pycnogenol, an extract of French maritime pine bark rich in OPCs, in the amount of 1.1 mg per 2.2 pounds of body weight per day for the first four weeks, and 1.66 mg per 2.2 pounds of body weight per day for the next four weeks. Compared with ultraviolet sensitivity before supplementation, the lower amount of Pycnogenol was found to significantly increase the amount of ultraviolet rays necessary to cause sunburn, and the higher amount was significantly more effective than the lower amount.