Requirements of dietary fats to meet nutritional needs & prevent the risk of atherosclerosis--an Indian perspective.

To arrive at the fat requirements for Indians, invisible fat and fatty acid compositions were determined in commonly consumed foods. Taking into account the WHO guidelines and the invisible fat intake of Indians, the visible fat requirements according to age, physical activity and physiological status were calculated. The data from both dietary and plasma fatty acids showed that while the requirements of linoleic acid (18:2 n-6, LA) were fully met due to their high levels in cereals and many vegetable oils, alpha-linolenic acid (18:3, n-3 ALNA) intakes were low. Long-term high intakes of ALNA or long chain n-3 polyunsaturated fatty acids (LCn-3 PUFA) reduce the risk of coronary heart disease (CHD). Metabolic studies were therefore conducted in Indian subjects to investigate the effects of using fish oils (LC n-3 PUFA) and ALNA rich oils (canola oil and mustard oil, MO) in comparison to oils which have negligible ALNA (groundnut oil, GNO and palmolein, PO) on plasma lipids, essential fatty acid (EFA) status and platelet aggregation. The results showed that at a level of 6-7 energy per cent LA, about 0.2 to 0.5 energy per cent LC n-3 PUFA or 1.4 energy per cent ALNA produced anti-atherogenic effects. However, high levels of erucic acid (22:1, EA) present in MO prevented these beneficial effects. Since absolute levels as well as the ratio of n-6 to n-3 PUFA are essential for optimal health, the use of more than one oil (correct choice) is recommended. However, it is necessary to evaluate the long-term health benefits of the recommended oil combinations before permitting commercial preparation and endorsing health claims. Regular consumption of plants foods which are good sources of ALNA can also contribute to improving n-3 status. Non-vegetarians, however, have the choice of eating fish to accomplish this.