Calorie intake and anthropometric measures of growth and anabolism as indicators of risk of cancer of the breast and large bowel

Abstract

Animal experiments have demonstrated that calorie restriction extends the life span and reduces tumor incidence. The underlying mechanisms of these effects are unknown, but presumably these mechanisms may be associated with the decreased anabolism induced by calorie restriction. To evaluate whether similar effects are also observable in humans, an analysis was conducted of data from the first National Health and Nutrition Examination Survey. Risk models that focused on markers of the anabolism: calorie intake, body weight, body mass index, basal metabolic rate and resting metabolic rate were constructed. The endpoints of interest studied were cancer of the breast and the large bowel. In a population of 13,792 people, 188 cases of breast cancer and 194 cases of large bowel cancer were diagnosed during the 16 years of followup. The average reported calorie intake was negatively associated with cancer risk, but it appears that this result may be a consequence of biased underreporting of calorie intake. Supportive of the hypothesis that increases in anabolic parameters are associated with cancer risk, people in the top quintile of the anthropometric variables were at increased risk of cancer. Of these variables, weight and body mass index performed less well as risk predictors than more direct measures of anabolism. In particular, the resting metabolic rate was most consistent in showing increased risk, with odds ratios for the upper quintile ranging from 1.9 to 2.3. The relationship of the resting metabolic rate and cancer incidence appears to be non‐monotonic, with the lowest quintiles at higher risk than the second quintile. These findings support the hypothesis that an increased metabolic rate is a risk factor for cancer and that calorie restriction might reduce cancer incidence through lowering growth and anabolism.

Notes

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