Importance of tocopherols beyond alpha-tocopherol: evidence from animal and human studies
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Abstract: Although the tocopherol content in food has been shown to be inversely associated with mortality from cardiovascular disease, dietary supplementation with alpha-tocopherol alone has a modest protective effect. The lack of natural tocopherols such as gamma- and delta-tocopherol in most vitamin E preparations may be a limiting factor for promoting health. Although alpha-tocopherol and gamma-tocopherol are 2 principle tocopherols in vegetable oils, the latter is in greater abundance in the edible oils processed in the United States. In contrast to alpha-tocopherol, gamma-tocopherol has biologic activity that potentially protects against chronic diseases such as inflammation. Evidence indicates that the mixed tocopherols found in native vegetable oils afford additive and synergistic activities that support their broader beneficial biologic functions. Both gamma- and delta-tocopherol may be necessary for preventing lipid peroxidation and in counteracting the prooxidant effect of a-tocopherol. Moreover, all tocopherols except beta-tocopherol inhibit smooth muscle proliferation. In our research, a preparation of mixed tocopherols, containing gamma-, 6 delta-, and alpha-tocopherol (5:2: 1), has been shown to have better antioxidant and anti-inflammatory actions than alpha-tocopherone alone. This mixture did not have any adverse effects in a limited number of preliminary clinical investigations. Thus, among the tocopherols, alpha-tocopherol is not the only important isomer for human health. Based on the evidence in this review, further research and additional clinical studies should be conducted on mixed tocopherol preparations. (c) 2005 Elsevier Inc. All rights reserved.
Author Keywords: tocopherols; alpha-tocopherol; beta-tocopherol; delta-tocopherol; gamma-tocopherol; cardiovascular disease
KeyWords Plus: CORONARY-HEART-DISEASE; GAMMA-TOCOPHEROL; VITAMIN-E; MYOCARDIAL-INFARCTION; MIXED TOCOPHEROLS; PLATELET-AGGREGATION; LIPID-PEROXIDATION; EPITHELIAL-CELLS; PROSTATE-CANCER; BETA-CAROTENE