Recent research has demonstrated that gamma-tocopherol, the main dietary source of vitamin E, has a very important role in supporting health. Gamma-tocopherol is a more effective antioxidant than alpha-tocopherol and may be an important factor for a healthy cardiovascular system. It also inhibits the COX-2 enzyme, according to in vitro tests. Research indicates that a ratio of gamma to alpha-tocopherol greater than 1:1 increases levels of both tocopherols in the body and that alpha-tocopherol alone may not be adequate to combat oxidative stress. Source Naturals GAMMA E 400 offers a 3:1 gamma to alpha-tocopherol ratio (200 IU equals 133 mg) and also contains tocotrienols from palm fruit which provides high concentrations of all four tocotrienols: alpha, beta, gamma, and delta. Sesame oil, rich in gamma-tocopherol, is used as the base.