A CASE-STUDY OF NUTRIENT INTERVENTION OF ORAL PRECANCEROUS LESIONS ININDIA

Tobacco chewing and/or smoking are strongly related to several cancers , mainly of the upper aerodigestive tract. Several studies on diet and cancer links suggest that micronutrients, particularly antioxidant vi tamins and minerals, are risk modifiers of cancers of epithelial origi n. This study looks at the impact of micronutrients such as vitamin A, riboflavin, zinc and selenium as intervention agents in subjects with and without precancerous lesions in a high risk group (reverse smoker s of chutta-rolled tobacco leaf). Reverse smokers from four villages w ere enrolled in the study. 150 subjects were supplemented with four nu trients, namely vitamin A, riboflavin, zinc and selenium in the form o f a capsule twice a week for 1 year. 148 controls received a placebo c apsule containing lactose for the same period. Clinical history and an thropometric data were collected from all the subjects and a clinical photograph of the palate was taken. Micronutrients were estimated in r andom blood collected from a sub-sample before and after the study. Mi cronutrients improved the vitamin A, riboflavin and selenium nutriture in the supplemented group with a concomittant regression of precancer ous lesions present on the palate. Clinically complete remission of wh ite, red and combination lesions was seen in 57% of subjects on supple ments whereas 8% on placebo showed a positive response. Further progre ssion of these lesions was seen in 10% of the supplemented group compa red with 47% in the placebo group (P<0.001). In the non-lesion group, new lesions appeared in 12% on supplements while more than 38% on the placebo developed new lesions (P<0.02). The results, coupled with the observation of a better nutritional status of vitamin A, riboflavin an d selenium in those who had a clinical response, suggested that a cock tail of nutrients as a prescriptive approach rendered the subjects at risk refractory to carcinogens in the environment. Since the study was a small straight trial and not double-blind, a large study with facto rial designs could provide answers to whether single nutrients can pro duce similar responses. Dietary intervention might perhaps be the long -term strategy for prevention of cancer.