Carcinogenicity of contaminants in indigenous edible oils.

Abstract

AbstractEdible oil is one of the essential constituents of Indian diet which has to be free of hazardous contaminants. A variety of oils are used in different parts of the country, e.g. ground‐nut oil, mustard oil, coconut oil, sesame oil, etc. A series of ground‐nut oil, mustard oil and soya‐bean oil samples have been tested for carcinogenicity due to possible contaminants: (i) solvent residues and (ii) argemone oil. The experiments are divided into two parts: I. Testing the carcinogenicity of solvent‐extracted edible oils, and II. Testing carcinogenicity due to argemone oil. Two strains of mice, inbred C17‐specially developed for testing environmental carcinogens‐and inbred Swiss from the Cancer Research Institute, have been used as test animals. Three routes of administration have been used: (i) cutaneous application, (ii) single and multiple subcutaneous injections and (iii) oral feeding by stomach tube.I. Solvent‐extracted oils: The results of testing experiments in 1966 indicate the carcinogenic effect of many indigenous solvent‐extracted ground‐nut oil samples as against machine‐expressed oils and imported soya‐bean oils that are mostly free of carcinogenic effect. The second batch of ground‐nut oil samples tested in 1969 after change of solvent to proper food‐grade n‐Hexane show significant improvement.II. Effect of argemone contamination: Pure laboratory‐expressed argemone oil, diluted in different concentrations in (i) imported soya‐bean oil, (ii) authentic expressed mustard oil and (iii) market tinned oil, as well as pure argemone oil control and other solvent controls, have been tested for carcinogenicity. The data indicate that argemone oil by itself is not carcinogenic at the dose levels tested. In combination with non‐carcinogenic soya‐bean oil and authentic mustard oil also it had hardly any carcinogenic effect. On the other hand, the market sample of tinned mustard oil was weakly carcinogenic by itself; the carcinogenic effect is significantly enhanced by addition of argemone oil at the 1 and 2% level. The data suggest that argemone oil has a co‐carcinogenic effect and the market sample of mustard oil possibly contains weakly carcinogenic principles other than the argemone oil. These observations invite further investigations on market samples of edible oils.