Coconut oil is extracted from the kernel or meat of the mature coconut harvested from the coconut palm. Throughout the `tropical world, it has provided the primary source of fat in the diets for health and general well being for generations. It is the characteristic cooking medium in most of the culinary preparations of the population in Kerala. It is uniquely different from most other dietary oils due to the multitude of its application in food, medicine and industry. It is composed of mostly medium chain fatty acids, which can be easily absorbed and stimulating the metabolic effects, which causes the body to burn more calories, thus fewer calories to be converted in to body fat. Human studies indicate that coconut oil consumption doesn’t cause increase in blood total cholesterol or LDL cholesterol, while it increases blood HDL cholesterol and decreases triglycerides.
Coconut oil contains only low levels of linoleic acid (2%). Since, linoleic acid is an essential fatty acid; using coconut oil as a sole source of dietary fat leads to essential fatty acid deficiency. Fortunately, the feature of Kerala diet is that rice is the primary calorie supplier. The habitual diet of Kerala also contains other cereals, vegetables and fish. This peculiar dietary pattern itself can provide the required amount of essential fatty acid per day as in the form of invisible fat. Our studies showed that feeding blends of coconut oil with rice bran oil (1:1) decreases lipid peroxidation and improved the lipid profile. In addition, coconut oil with rice bran oil increased the utilization of glucose and promotes the conversion of glucose into glycogen in rats. The results showed that the use of coconut oil - rice bran oil blend is more beneficial than the use of single oil like sunflower oil. Feeding coconut oil with rice bran oil in 2:1 ratio is superior in cholesterol lowering action and antioxidant protection than those fed saffola oil or coconut oil alone. Studies confirmed that inclusion of coconut oil with rice bran oil and fish oil beneficially modified its effects on lipid metabolism, thrombotic factors and inflammatory markers.
It is now become a trend rather than a necessity to include fried food in the daily diet by ignoring health and giving priority to taste and smell. Fried foods are prepared using dietary oils heated at high temperature (usually above 200°C). When the oils and fats are heated to high temperature for frying, a wide spectrum of new volatile and non-volatile components are formed, which are absorbed along with this fried items. Study showed that during heating, the levels of peroxides and the carbonyl value of individual oils were increased. Heating also results in the higher polymer content and viscosity of the oils. Dietary ingestion of both saturated and unsaturated fats subjected to heating causes harmful effects. Studies showed that feeding heated oils promote lipid peroxidation and hyperlipidemia. But these effects were seem to be lower in rats fed heated coconut oil than those fed heated sunflower, groundnut and saffola oils. Dietary oils repeatedly heated at elevated temperature results in significant alterations in lipid profile, antioxidant status and platelet function as compared to fresh oils. These deleterious effects were lower in heated coconut oil compared to mustard oil and sunflower oil. In another study, we found that feeding coconut oil in aged rats decreases the ageing associated oxidative stress and improved the total antioxidant capacity compared to sunflower oil.