Fat
Fats come from animals, fish and vegetable sources. Animal fats are largely what are called saturated. We need some of these – including cholesterol (although our bodies actually manufacture this, see part 14) – to make our own hormones like cortisone and the sex hormones, but too much can be provided in the diet which is quickly converted to body fat (as are excess glycaemic foods).
Vegetable fats, which included olive oil, nut and seed oils, are unsaturated fats. These contain the essential fatty acids which the body cannot manufacture, and which are necessary for making healthy tissues (and many indeed reverse the effects of saturated fats). The best are mono-unsaturated fats such as olive oil. Some fish oils are also unsaturated and essential, and can be protective.
These are two main families of unsaturated fatty acids: the Omega-6 and Omega-3 series. The chart following shows where they are to be found.
FATTY ACID FOOD SOURCE ENRICHED SOURCE
Omega-6 – linoleic acid (LA) Vegetables, seeds and nuts and oils Corn, pumpkin, sunflower, sesame, corn, walnut, soya and wheatgerm oils
Omega-6 – gamma linolenic acid (GLA) Seeds, nuts and oils As above, also evening primrose oil, borage oil, blackcurrant oil
Omega-3 alpha linolenic acid (ALA) Seeds and nuts Flax seed, linseed, pumpkin, and evening primrose oil
Omega-3 – eicosapentaenoic acid (EPA) Seafood Fish oils
Omega-3 – docosahexaenoic acid (DHA) Seafood Fish oils
When fats are eaten with carbohydrate, they slow the rate of absorption of the carbohydrate into the bloodstream. The biggest deficiency of all in the West is of essential fatty acids. So fat is necessary for good health, but an excess intake, however, is not recommended.
