Effects of lifestyle on micronuclei frequency in human lymphocytes in Japanese hard-metal workers

Abstract Objective The risks of cardiovascular disease, cancer, and other major causes of mortality are largely attributable to lifestyle factors such as smoking, alcohol drinking, hours of working and sleeping, physical activity, diet, and stress. Earlier studies have suggested that an unhealthy lifestyle is also associated with increased lymphocyte sensitivity to mutagens, oxidative DNA damage level, and leukocyte DNA damage. In order to explore the genotoxicity of unhealthy lifestyle, we evaluated the effect of overall lifestyle as well as some individual lifestyle factors on micronuclei (MN) frequency in cultured human lymphocytes. Method The study was conducted among 208 healthy adult (19 to 59 years) male Japanese hard-metal workers. The subjects were divided into groups according to their self-reported good, moderate, and poor lifestyles based on their responses to a questionnaire regarding eight health practices (cigarette smoking, alcohol consumption, sleeping hours, working hours, physical exercise, eating breakfast, balanced nutrition, and mental stress), the presence or absence of each of which was summed to obtain a health practice index (HPI: range 0–8). Peripheral blood was taken and the cytokinesis-block micronuclei (CBMN) assay was performed. Results Total lifestyle quality as measured by the HPI was strongly negatively associated with MN frequency in cultured human lymphocytes ( p p p Conclusions Taken together, these findings indicate that poor lifestyle habits significantly increase MN frequency in human lymphocytes.