Fats- Which ones heal? Which ones harm?
For generations, we have been told “fat will make you fat”; how are we now supposed to wrap our heads around this complete about-face? The answer is to learn all the facts and understand why recent discoveries have turned previous medical theory on its head!
In those who eat no fat, there can be very serious health implications, which may be irreversible, as fat is an essential dietary item. Dietary fats are responsible for the following functions:
- Regulation of the metabolic rate- If dietary fats are deficient, the metabolic rate will slow down so that calories are burnt off less efficiently.
- Maintenance of the structural and functional quality of cell membranes and internal organs. If dietary fats are lacking, cells will not function efficiently and will not produce enough cellular energy, resulting in fatigue and a sluggish metabolism.
- Production of hormones- Sex hormones and the stress hormone, cortisone, are made from cholesterol and, if inadequate cholesterol is consumed, the liver will make enough cholesterol for the body to use for making steroid hormones.
- Cholesterol is also used to make cell membranes and the insulation around nerve fibres. If the liver is healthy, it will manufacture the good cholesterol called HDL cholesterol, which prevents hardening of the arteries. If the liver is unhealthy and fatty, it will manufacture excessive amounts of the bad LDL cholesterol, even if a low fat diet is followed.
- Production of prostaglandins and eicosanoids, which transmit messages between body cells
- Anti-inflammatory function
- Healthy appearance of the hair and skin
These are generally known as the essential fatty acids, because the body is unable to make them and they are essential for good health. Because our food has become increasingly processed and many people erroneously follow low fat diets, we have found that deficiencies of essential fatty acids are very common.
The essential fatty acid groups are known as omega 3 and omega 6 fatty acids. This difference is based on their chemical structure and function.
Omega 3 fatty acid is known as alpha- linolenic acid.
Omega 6 fatty acid is known as linoleic acid.
Supplementing with essential fatty acids may benefit you as they reduce:
- Heart disease
- Blood clotting
- Insulin resistance
- The risk of diabetes
- The risk of irregular heartbeats
Good sources of essential fatty acids include:
- Organic egg yolks
- Walnuts and other nuts (walnuts contain the highest levels of omega 3 fatty acids)
- Seeds and their cold pressed oil including sesame seeds, pumpkin seeds, sunflower & safflower
- Legumes such as soy beans
- Cold water fish such as mackerel, cod, herring, tuna, salmon and sardines
- The leaves and seeds of most plants especially dark green leafy vegetables
- Whole grains
- Evening primrose oil
- Borage seed oil (starflower oil)
- Blackcurrant seed oil
When buying oils make sure they are good quality, cold pressed, unprocessed, unrefined oils. They are usually available in glass containers or bottles of a darker colour than transparent plastic. Essential fatty acids are very fragile and are easily damaged and oxidised by exposure to heat, air and light. To protect them in their original form, it is best to buy them and keep them in opaque containers in the refrigerator. Olive or palm oils are best for high temperature cooking such as stir-fries or sautéing. Flaxseed oil must not be heated, as this will damage the fragile omega 3 fatty acids.
Trans-fatty acids are man-made fats that originate from vegetable oils. Margarines are the best-known examples and are chemically processed, turning them into “hydrogenated vegetable oils”. This chemical process makes the fat more saturated, which means it is solid, at room temperature. Trans-fatty acids and other partially hydrogenated vegetable oils are totally unnatural and our cells find it very hard to use them. Trans-fatty acids not only block the use of the natural unprocessed essential fatty acids that are eaten, they end up being deposited into cell membranes. The problem is that they do not fit the cell membranes because they are the wrong shapes, so the membranes end up being weakened, with holes in them.
The liver doesn’t know how to utilise trans-fatty acids efficiently, and as a result, the trans-fatty acids may accumulate in it which causes fatty liver, especially if they are eaten with a lot of refined carbohydrates.
Trans-fatty acids have a very adverse effect on blood fats; they cause an elevation of undesirable, LDL cholesterol, triglycerides and lipoprotein (a), and lower the good, HDL cholesterol. This disturbance of blood fats is a potent predictor of cardiovascular disease.
Sources of bad unhealthy trans-fatty acids include:
- Many margarines
- Foods deep-fried in polyunsaturated vegetable oils such as chips and batter.
- Potato chips in packets – they may state they are cholesterol free, but so what- cholesterol is not the enemy!
- Many fast foods.
- Many baked and packaged foods – biscuits, cookies, cakes, buns, breads, doughnuts and muffins, etc.
- Many prepared foods such as mayonnaise, salad dressings, dips and spreads, etc.
- Many brands of candy bars and snack bars.