ENVIRONMENTAL AND PHYSIOLOGICAL INFLUENCES ON HUMAN NATURAL-KILLER-CELL ACTIVITY IN RELATION TO GOOD HEALTH PRACTICES

We examined the association of natural killer (NK) cell activity with a number of life style factors by a cross-sectional analysis on 2892 Japanese individuals. The following habits were found to be associated with increased NK activity: 1) alcohol drinking (males, P<0.05), 2) not smoking cigarettes (males and females, P<0.001), 3) increased intake of green vegetables (females, P<0.001), 4) increased intakes of meat, milk, dairy products, and soyabean products (males, P<0.01), 5) daily workload of less than 3 hours per day (females, P<0.05), 6) regular meals (females, P<0.05), 7) regular sleep of more than 7 hours (females, P<0.05), 8) proper body weight. In addition, systolic blood pressure showed a positive correlation with NK activity (P< 0.001), while proportion of helper/inducer (OKT4+) T cells and fraction of beta-globulin showed negative correlations (P<0.001). We thus found that the living habits associated with increased NK activity were consistent with generally accepted good health practices, except alcohol drinking.