The Form of Vitamin E in Food Reduces Inflammation Triggers

Bruce Ames
University of California Berkeley
P01ES01896

Background: Chronic inflammation not only causes pain as in rheumatoid arthritis, it is also an important factor in fatal and disabling conditions such as asthma, hepatitis, diabetes, cancer, neurodegenerative disorders, cardiovascular disease, etc. Inflammatory responses are mediated by the production of compounds known as eicosanoids, which are derived from arachidonic acid. Prostaglandin E2 (PGE2), an eicosanoid produced by a cyclooxygenase-catalyzed oxidation reaction of arachidonic acid, is believed to cause pain and fever. PGE2 and another oxidatively produced compound, leukotriene B4 (LTB4), and the enzymes that catalyze their production have been recognized as key targets for drug therapies in inflammation-associated diseases.

These researchers recently reported that γ-tocopherol (γT), the major form of vitamin-E found in the U.S. diet, and its major metabolite inhibit the production of PGE2. However, α-tocopherol (αT), the major form of vitamin-E found in tissues and in most vitamin supplements proved to be much less effective in this regard. The current study was performed to further investigate these effects in a mammalian model as opposed to an in vitro system.

Advance: Administration of γT, but not αT, to laboratory rats significantly reduced PGE2 and LTB4 synthesis. γT also significantly reduced the inflammation-mediated increase in a biomarker for lipid peroxidation. The inflammatory cytokine, tumor necrosis factor-α, was also reduced by γT.

Implication: This study shows the importance of γT in reducing the production of pro-inflammatory products and attenuated inflammation-mediated damage in a rat model. This observation, along with previous studies from this laboratory, strongly suggests that γT is important to human health and deserves further study. It also suggests that people suffering from inflammatory diseases might respond well to additional γT in their diet or from γT-containing supplements.

Citation: Jiang Q, Ames BN. Gamma-tocopherol, but not alpha-tocopherol, decreases proinflammatory eicosanoids and inflammation damage in rats. FASEB J. 2003 May;17(8):816-22.