Fats and oils are integral parts of healthy diets. Fatty acids are the building blocks of various lipids and are classified into 3 groups – saturated fatty acids (SFAs), monosaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Humans cannot synthesize the parent PUFAs namely linoleic acid (LA, 18:2n-6) and alpha linoleic acid (ALA, 18:3n-3). LA and ALA are dietary essential fatty acids and ALA is a precursor for synthesis of longer chain omega-3 fatty acids. Studies have shown that PUFAs of n-6 and n-3 series and their metabolic products regulate the production of lipid cellular mediators – lipoxins, E series resolvins (from EPA), D series resolvins and neuroprotectins D1 (from DHA) shown to have potent anti-inflammatory and neuroprotective effects.
Several groups of dietary lipids have been identified to play a key role in facilitating formation such as cellular mediators, responsible for providing optimal health benefits such as promoting cell growth, essential for brain functions, reducing risk of cardiac diseases. While some health benefits are derived from consumption of fats in form of short chain and medium chain fatty acids, evidences suggest that the PUFAs are the most important bioactive lipids. PUFA are found in plant seed oils and foods of animal origin. PUFAs specifically ALA, GLA are activators of PG1 and PG2 syntheses and have been found to prevent hypertension. CLA synthesized from linoleic acid has been found to suppress atherosclerosis, insulin resistance and has potential anticarcinogenic effect. Omega-3 fatty acids consumption during pregnancy is significant in fetal development. They are required during the prenatal period for the formation of cell membranes and synapses of neurons.
EPA, DHA and CEPA have been more emphasized on with respect to their role as bioactive lipids. WHO/FAO expert group have given specific recommendations for fat intake nutrient goals related to percentage of energy intake. Recommendations also include the type of oils (corn, canola, safflower, sunflower, ground etc.) to be used and their judicious combination necessary to provide optimal health benefits. Apart from oils, most of the hidden fat in foods of vegetable origin such as cereals, nuts, oil seeds (especially flax seeds) and green leafy vegetables are known to be good sources of ALA. Various oily fish, eggs, poultry are known to be good sources of DHA.
Ghee is one of the indispensible types of fats in Indian diets. According to Ayurveda consumption of ghee has many health benefits. Ghee has stable saturated bonds and so is lot less likely to form the free radicals. The short chain fatty acids present in ghee are also metabolized very readily by human body. Ghee is also good for nerves and brain. Ghee contains a high concentration of butyric acid, a fatty acid that contains anti-viral properties. It promotes learning and increased memory retention.