Effects of a 6-Month Vitamin Intervention on DNA Damage in Heavy Smokers

• Published in: Cancer epidemiology, biomarkers & prevention biomarkers & prevention, 2000-12, Vol.9 (12), p.1303-1311
• Main Authors: JACOBSON, Judith S, BEGG, Melissa D, WEN WANG, Liane, QIAO WANG, AGARWAL, Meenakshi, NORKUS, Edward, VISHWA NATH SINGH, YOUNG, Tie-Lan, YANG, David, SANTELLA, Regina M
• Format: Article
• Language: English
• Subjects: Adult; Ascorbic Acid - therapeutic use; beta Carotene - therapeutic use; Biological and medical sciences; Carcinogenesis, carcinogens and anticarcinogens; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - analysis; DNA Adducts - analysis; DNA Damage - drug effects; Drug Therapy, Combination; Female; Follow-Up Studies; Foods and miscellaneous; Glutathione Transferase - analysis; Humans; Linear Models; Male; Medical sciences; Odds Ratio; Smoking - adverse effects; Tumors; Vitamin E - therapeutic use
• ISSN: 1055-9965; 1538-7755

Because their formation is associated with tumor development in specific tissues, DNA adducts have potential usefulness as intermediate end points in chemoprevention studies. To determine the efficacy of a combination of antioxidant vitamins (vitamins C and E andβ -carotene), a randomized clinical trial was conducted among heavy smokers using DNA damage as the end point. Immunological methods were used to measure polycyclic aromatic hydrocarbon-DNA adducts and oxidative DNA damage (8-oxo or hydroxydeoxyguanosine) in mononuclear and oral cells. A total of 121 subjects were randomized to the 6-month intervention and received either vitamins or placebo. Dropout rates were higher in the placebo than in the vitamin group; 65% of subjects in the vitamin group, but only 47% in the placebo group, provided specimens at 6 months. Plasma levels of all three antioxidants rose significantly in the vitamin group but not in the placebo group. All four measures of DNA damage decreased in both groups; the between-group differences were not statistically significant. These data do not provide clear evidence that antioxidant vitamin intake prevents DNA damage. However, the study demonstrates that DNA damage is a useful end point in chemoprevention trials.