Vegetable oils do not contain cholesterol. In fact, they contain essential fatty acids (EFA) like the monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) that, when present in the right proportion, keep the low density lipoprotein (LDL) or bad cholesterol transporter levels down and help to elevate the high density lipoprotein (HDL) or good cholesterol transporter levels. So, refining oil does not remove cholesterol as is widely believed. The process of refining improves the consistency, colour and smell of oil. In fact, the chemicals and heat involved in refining oil actually destroy many of the EFA which are so crucial to maintaining the balance between the good and bad cholesterol. Unrefined cold pressed oils should therefore be the oils of choice. It has been conclusively proved that olive oil which has a high percentage (74.5%) of MUFA especially oleic acid, not only lowers total and LDL cholesterol, but also lowers triglyceride levels, increases HDL levels, helps in blood pressure control, has antithrombotic properties (keeps the blood from clotting in the arteries) and helps to improve insulin sensitivity (directs glucose into the cells more efficiently for energy production). So a couple of teaspoons of olive oil mixed into salad or used to prepare stir fried vegetables would be beneficial to health. In addition to the benefits of MUFA in general, olive oil produces LDL that is resistant to peroxidation and is therefore invaluable in the prevention of cardiovascular disease. Since Indians do not like to do all their cooking in olive oil, sesame oil (gingelly or til), groundnut and rice-bran oils could be used to obtain MUFA. These oils contain from 40-50% of MUFA.
PUFA are also beneficial and consist of the omega 3 and omega 6 fatty acids which should be present in the proportion 1:2-5. The omega 3 fatty acids lower triglycerides, prevent inflammatory changes in the arteries, keep the blood from clotting and help to maintain a regular heartbeat. Omega 3 fatty acids are found in fish, egg yolk, dark green leafy vegetables, walnuts, black gram, kidney beans or rajma, wheat, fenugreek, mustard oil (14.5%) and soya oil (6.5%). Since a vegetarian diet contains a low percentage of these omega 3 fatty acids, oils that contain a very high percentage of omega 6 fatty acids (sunflower, safflower and corn oils) should not be used. This will ensure the ratio between the two is maintained. Once again, sesame, soya bean, groundnut and rice-bran oils provide the right percentage of PUFA (30-50%) and should therefore are the oils of choice. It is always good to use a combination of oils so that we receive all the fatty acids contained in them. Canola oil may also be used. Use mustard oil occasionally for special preparations, since it contains a significant percentage of omega 3 fatty acids. However, it also contains 46.5% of erucic acid (unsaturated omega 9 fatty acid), which has not yet been proved to be beneficial and so must be used only occasionally. If 50g of soya bean is included in the diet, it will not be necessary to use the soya bean oil for cooking, since 50g of soya bean will provide 10g of soya oil. Do not be afraid to use the right quality vegetable oils as a natural medicine to protect you from cardiovascular disease. As Hippocrates urged, use food as medicine.
Indians have the higher rate of heart disease and 25% of heart attacks among men occur below the age of 40 while in other parts of the world the age is 60. Indians have low HDLs which in all probability have resulted from using the wrong quality of oils and eating a high carbohydrate diet. Notice how the Europeans make it a point to add healthy oils to their diet, while we in India are often advised to go on an “oil-free diet"! Use oil; do not misuse it. Use a maximum of 20ml per adult per day. This works out to about 600 to 750 ml of oil per adult per month. Coconut oil and palm oil contain a high percentage of saturated fat (SAFA) which might elevate blood cholesterol levels, as do vanaspati and margarine which are hydrogenated oils and contain trans-fatty acids which also elevate the LDL. It is best to avoid using these as cooking mediums. Reheating oil many times, as for example, by using the same oil repeatedly for deep frying, also hydrogenates it and this becomes harmful to the body. For this reason it is advisable not to eat deep fried foods that have been prepared outside the home like chips, samosas, potatos, murukkus etc. We do not know which oils have been used and how often the same oil has been reheated. Items that have been deep fried at home in groundnut, sesame, rice-bran or olive oils are not harmful. The oils that are left over after deep frying should be used up to prepare food on the following days.