Maize meal, non-esterified linoleic acid, and endemic cancer of the esophagus--preliminary findings.

Endemic cancer of the esophagus has shown a positive association with the consumption of maize meal. It has been postulated that this association is due to the conversion, in the stomach mucosa, of the linoleic acid contained in maize meal to prostaglandin E2. The proportion of non-esterified linoleic acid available in the stomach may therefore be an important factor. Samples of commercially prepared maize flour, cooked and uncooked, and other maize-based foods were analysed for total and free content of various fatty acids using gas-liquid chromatography. High levels of non-esterified fatty acids (11 to 42% of contained fatty acids) were found both in maize meal and in foods prepared from it. In food prepared from maize meal, 49 mg to 363 mg non-esterified linoleic acid per 100-g sample was found. High levels of non-esterified linoleic acid in the diet, causing raised intragastric production of prostaglandin E2 and profoundly affecting the normal pH and fluid content of the esophagus, may create a predisposition to esophageal carcinogenesis.