However, only Rice Bran oil and Groundnut oil has a ratio of SFA, MUFA and PUFA closest to WHO recommendations.
With advances in science and technology, processing methods as well as transportation, a number of new edible oils are now available in the market, providing a wide range of options for consumers. Different oils have their own advantages and disadvantages. Hence selecting the best oil keeping in mind the intended use, taste, price, appearance, shelf life and most importantly, nutritional value and health issues is important as well as challenging.
A study of oils based on their composition reveals that rapeseed oil, olive oil, groundnut oil and rice bran oil have the highest amount (> 50 per cent) of mono-unsaturates. However, only Rice Bran oil and Groundnut oil has a ratio of SFA, MUFA and PUFA closest to WHO recommendations. (See table)
Filtered groundnut/ peanut oil has been used in India since generations. Refining of oil was introduced in the 1950s. The first refined groundnut oil was called "Sipahi" but it gained popularity under the brand name "Postman". Groundnut (peanut) oil being high in mono-unsaturates, is more stable and usually does not require artificial additives. It is considered to be the finest all-round oil for cooking and frying. It is extremely robust and produces fewer flavour defects with long term use as compared with many other oils. Peanut oil is also considered superior in the manufacturing of pourable dressings because of its ability to hold solids in suspension for a longer time. It is therefore extensively used in place of olive oil as a salad oil and in the production of mayonnaise. Groundnut oil also contains natural antioxidants like tocopherol and tocotrionols as well as sterols, which are of nutritional importance. Amount of these substances present in filtered oil is 137-827 ppm of tocopherols, 38-474 ppm of tocotironols and 900-2856 ppm of sterol. One should note however, that about 50 per cent of these components are retained after the refining process.
Unfortunately, in the last two decades, the general opinion of eating less fat in an attempt to reduce degenerative diseases like CVD, hypertension and diabetes has resulted in labeling of certain foods as "bad" simply due to their fat content. Peanuts were one of these casualties. However, recent epidemiological and clinical studies have revealed that regular consumption of these nuts actually reduces heart disease. It also provides protection against cancer, obesity and Type II diabetes. Another adverse claim against peanut oil was the development of allergic reactions to peanuts. It is important to note that while allergic reactions are caused by proteins in a substance, during processing of peanuts to produce oil, all proteins are completely removed. Moreover, peanut is not actually a nut, but a legume. It is a member of the pea and bean family. A person with nut allergy (which is relatively common) may not necessarily suffer an allergic reaction to peanuts or peanut oil. If at all there is an undesirable reaction, it could be due to aflotoxin contamination of peanuts.
By summarising recent research data, it is recommended that dietary fat should provide about 30 per cent of the total calories in the daily diet. Higher intake of fat may increase the risk of obesity, CVD, hypertension, immune disorders, etc. At the same time, if less than 15 per cent energy is from fat may lead to PCM related degenerative diseases, poor brain growth, neuro-disorders and poor immunity. As far as type of fat is concerned, the present consensus among the scientific community is for consumption of fats with high percentage of MUFA like groundnut oil, rice bran oil or canola oil.
Keeping in mind all above factors, Groundnut Oil seems to be a good choice for the Indian market. It is readily available at an affordable price as compared to the other two recommended oils, viz. rice bran and canola. However, while following a diet consisting of groundnut oil as the main source of fat, care should be taken to obtain 1-3 gm of n3 essential fatty acids, which are not present in groundnut oil. These can be obtained from other food sources like fish oil, flaxseed oil, green leafy vegetables, walnuts, cereals etc.