Reduction of DNA damage in older healthy adults by Tri E (R) Tocotrienol supplementation

Objective: The free radical theory of aging (FRTA) suggests that free radicals are the leading cause of deteriorating physiologic function during senescence. Free radicals attack cellular structures or molecules such as DNA resulting in various modifications to the DNA structures.. Accumulation of unrepaired DNA contributes to a variety of disorders associated with the aging process. Methods: A randomized, double-blinded placebo-controlled study was undertaken to evaluate the effect of Tri E (R) Tocotrienol on DNA damage. Sixty four subjects 37-78 y old completed the study. A daily dose of 160 mg of Tri E (R) Tocotrienol was given for 6 months. Blood samples were analyzed for DNA damage using comet assay, frequency of sister chromatid exchange (SCE), and chromosome 4 aberrations. Results: Results showed a significant reduction in DNA damage as measured by comet assay after 3 mo (P < 0.01) and remained low at 6 mo (P < 0.01). The frequency of SCE was also reduced after 6 mo of supplementation (P < 0.05), albeit more markedly in the >50 y-old group (P < 0.01) whereas urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were significantly reduced (P < 0.05). A strong positive correlation was observed between SCE with age, whereas weak positive correlations were observed in DNA damage and 8-OHdG, which were reduced with supplementation. However, no translocation or a stable insertion was observed in chromosome 4. Conclusion: Tri E (R) Tocotrienol supplementation may be beneficial by reducing DNA damage as indicated by a reduction in DNA damage, SCE frequency, and urinary 8-OHdG. (C) 2008 Elsevier Inc. All rights reserved.