Relationship between plasma concentrations of β‐carotene and α‐tocopherol and life‐style factors and levels of DNA adducts in lymphocytes

Abstract

β‐Carotene and α‐tocopherol have been thought to reduce risk of lung cancer. Whether β‐carotene and α‐tocopherol influence human DNA adducts, indicators of biologically effective doses of carcinogens, has been seldom studied. In this cross‐sectional study, we measured plasma β‐carotene and CL‐tocopherol in 192 healthy men and DNA adducts in lymphocytes in 104 of the subjects. Because genetic polymorphism ofcytochrome P‐4501A1 (CYP1A1) and glutathione S‐transferase M1 (GSTM1) has been associated with interference information of reactive intermediates and detoxification of polycyclic aromatic hydrocarbons, we also obtained data concerning genetic polymorphism of CYPIAI and GSTM1. In multiple regression analysis, parameters such as alcohol consumed per day, high‐density lipoprotein cholesterol, Quetelet index, and cigarettes smoked per day were correlated inversely, whereas age, plasma α‐tocopherol, and intake frequency of fruits were correlated positively with plasma β‐carotene concentration. DNA adduct levels of high plasma β‐carotene or α‐tocopherol groups were not significantly different from the DNA adduct levels of low plasma β‐carotene or α‐tocopherol groups among current smokers or nonsmokers. In variant states of CYP1AI or GSTM1 polymorphism, after controlling for effect of cigarettes smoked per day, no significant correlation was found between plasma β‐carotene or α‐tocopherol and DNA adduct levels. These results indicated that alcohol consumption, cigarette smoking, and plasma α‐tocopherol have a close relationship with plasma β‐carotene. The plasma β‐carotene and α‐tocopherol were not likely to influence the level of DNA adducts in lymphocytes.