Cancer risk in relation to fat and energy intake among Hawaii Japanese: a prospective study.

This study assesses the impact of fat and energy consumption upon cancer risk in a prospective study of 8,006 Japanese men, who have developed 885 incidence cancers since initial examinations were completed between 1965 and 1968. Energy intake was not related to any incidence cancer. The mean total fat intake was unrelated to the risk of developing cancers in the stomach (n = 130), lung (n = 145), urinary bladder (n = 51), pancreas (n = 25), prostate (n = 141), liver (n = 22). There was a weak inverse association between mean fat intake and colon cancer. There was a statistically significant inverse relation between mean daily fat intake and all other cancers (n = 118). There was a weakly positive association between fat intake and rectal cancer (n = 71). When assessed on the basis of quartiles of fat intake, there was a statistically significant negative association with colon cancer risk (p = 0.03); and weaker negative trends for lung cancer (p = 0.076) and all other cancers (0.076). These findings are in essential agreement with the results of a 10-year mortality study of the cohort. The fat intake of men who have developed cancer is substantially lower than that of men who have developed coronary heart disease. These findings cast doubt upon the importance of fat intake as a risk factor for cancer at sites other than the rectum.