Capsaicin is the pungent material in capsicum fruits which is one of the most common food ingredient used daily in many tropical countries. The average capsaicin in diet consumed by Thai people is approximately 14 mg %. An experiment in rats fed with capsaicin in six different diets for 28 and 56 days, normal diet, high-protein and low- protein diets, with or without capsaicin, were similar in protein and carbohydrate content to those consumed by the people of the central, southern and northeastern régions of Thailand, respectively. It showed that there was a reduction in absorptive ability of the epithelial absorptive cells influenced by capsaicin. The remained of absorptive cells from capsaicin injury could absorb added amount of protein in the diet which was adequate for the normal growth. The increase in the number of goblet cells in all capsaicin groups represented a protective mechanism by producing excess mucous. Feeding of red pepper (5%) and synthetic capsaicin (15 mg%) in rats for 12 months was inves- tigated.21 Red pepper (5%) increased in food intake, weight gain over the control. Synthetic capsaicin (15 mg%) lowered significantly the food intake, weight gain at 4 weeks. Long term feeding of red pepper (5%) and synthetic capsaicin (15 mg%) did not affect growth rate or cause mortality.
