Essential fats

If you have been doggedly avoiding fat in an attempt to lose weight — this approach is WRONG. You need fats in your diet. Your brain consists mostly of fat, and your intelligence, heartbeat and muscular movements all depend on it. The only way in which your body can send electrical messages through living tissue is via your nerve cells and their connectors, which again are made of fat.

The fact is that some fats (known as lipids) are essential. They act as the second energy reserve behind glycogen, providing most of their energy at around 70 per cent of maximum heart rate. Endurance athletes utilize fat as an energy source more than other sports people and this is why they tend to be lean.

Fats are not just for energy, though. Their many other functions include insulating important organs, carrying fat-soluble vitamins and regulating hormone levels. If you're a female athlete and you experience a loss of your periods, this may be due to extremely low body fat, for this plays a vital role in the activation of the female hormone oestrogen.

Fats also contribute to health in many other ways — provided they are of the right kind. In an attempt to warn people about the risk of consuming toomuch fat, certain groups have created the impression that all fats are bad, but this simply is not true.

Are you eating the wrong fats?

Many people in the Western world are getting 45 per cent of their calorific intake from fats, but these are junk fats that the body cannot use, so these people are just as fat-deficient as those on extremely low-fat regimes.

THERE ARE TWO MAIN TYPES OF NATURAL FATS:

1. Saturated fats come primarily from animal sources such as meat and dairy products, and from coconut and palm-kernel oil; they are solid at room temperature. They provide the body with a stored form of energy in fat cells.

2. Unsaturated fats are found in vegetables, nuts, grains and seeds, and in fish and game; they are liquid at room temperature. They contain two fatty acids that are essential to life and, more importantly, that the body cannot produce itself. These are linoleic acid (omega-6) and linolenic acid (omega-3) From these two 'essential fatty acids' your body can make all the other fatty acids it needs.

Is it just a case of cutting out saturated fat?

Saturated fat gets a bad press, and a diet too heavy in it has been closely linked to cardiovascular disease. However, there is another fat with an equal capacity to harm: hydrogenated fat.

Hydrogenated fat is solid or semi-solid at room temperature (the best example being margarine). It is created when a liquid oil (such as corn oil) has hydrogen added to it, changing its chemical structure. This in turn can interfere with the metabolism of some essential fatty acids. Research has shown that the trans fats in hydrogenated fats can increase LDL (poor) cholesterol,decrease HDL (good) cholesterol and thus raise the risk of coronary heart disease. Hydrogenated fat is found in almost all processed foods, plus frozen convenience foods and deep-fried fast food. This is another good reason to say goodbye to junk food and hello to fresh produce.

If you usually ingest high amounts of processed fats and use commercially altered oils for cooking, then you are certainly not getting the balance of fats that your body needs.

Why don't food manufacturers use healthier oils?

Even though the food industry uses vegetable oils that contain a reasonable amount of omega-6 fatty acids, they avoid omega-3s because these are more susceptible to oxidization — in other words, they go rancid quickly and don't have a long shelf life.

Ironic, isn't it? Food manufacturers quite happily promote food under the guise of lowering cholesterol and reducing heart disease, but they are ignoring one of the fats essential to health. So unless you are eating high amounts of fish, fish oils, leafy vegetables, nuts, unrefined olive oil, tofu or flaxseed oil, your ratio of omega-6 to omega-3 fats is probably screwed up, and this in turn will be screwing up your health.

The current Western diet is much higher in omega-6 fatty acids than omega-3's. Remember those healthy Palaeolithic people we were discussing earlier? They were eating equal amounts of both.

How is this relevant to body weight?

If you are eating a diet with a good balance of omega-6 and omega-3 fatty acids, this will affect your body in beneficial fat-burning ways:

• Your metabolic rate will be increased, as will the metabolism of fats, so more stored fat will be burned for energy
• Your cells' sensitivity to insulin will be increased, so that it regulates blood- sugar levels more effectively
• The ratio of insulin to glucagons will improve, which will unlock the fat- storage banks and again allow fat to be burned as energy
• Natural appetite suppressants will kick in.

So if you want to improve your chances of losing weight, you need to up your intake of omega-3 and other healthy fats.

Essential fats Q&A

Q. How often should I eat oily fish per week if I want to consume enough omega-3 fatty acids?

A. You should aim to eat oily fish a minimum of 2-3 times per week, or ensure you use flaxseed oil regularly on salads to raise your levels. Try to eat fish from as safe a source as possible as many coldwater fish are contaminated with heavy metals and pesticides.

Q. How can I avoid hydrogenated fat?

A. Cut out processed food and only use cold-pressed un-refined oils such as olive oil, or coconut oil for cooking. Don't eat fast food that has been deep-fried and avoid butter type spreads. If you did this, then you should be able to avoid consuming dangerous trans fatty acids.

Health Concern: FAT?

The term "fat" includes fats from meat, fish, poultry, and dairy products as well as vegetable oils and the nuts, seeds, and grains from which they have been extracted. There are two basic kinds of fats—saturated, occurring mostly in animal foods (although some vegetable fats such as the kind that coconut contains fall into this category too), and unsaturated, in the form of vegetable oils such as safflower, corn, and sunflower, and in seeds and nuts. Fish tends to contain more unsaturated than saturated fats, meat more saturated than unsaturated.

Whether saturated or unsaturated, all the fats you eat rapidly form a film around blood cells and platelets, creating a kind of sludge which causes them to stick together. This clumping significantly interferes with circulation by clogging blood vessels and even temporarily closing down small capillaries. As a result, your cells do not receive all the oxygen and nutrients they need to function efficiently. They only run at about 80 percent capacity. This interferes with cell metabolism as well as with the efficient elimination of cellular and tissue wastes.

The chemical structure of an unsaturated fatty acid differs from its saturated brother in that at least two of the carbon atoms in its formula are free. This means that they have no hydrogen atoms attached to them, as the molecule of a saturated fatty acid does. It was long thought that while saturated fats were bad for you, unsaturated fats were good. For unsaturated fats have been shown to reduce cholesterol levels in the blood, and therefore were believed to be helpful in preventing arteriosclerosis and coronary heart disease. That is the reason we have been encouraged in the last thirty years or so to include plenty of polyunsaturates in our diet by switching from butter to margarine and vegetable oils. The catch is that although unsaturates do this, like all fats they still raise triglyceride levels (another factor linked with coronary heart disease) and they also create the same clumping as the saturated fats do, which leads to tissue anoxia.

Women have also lately been encouraged by poorly informed writers to include lots of polyunsaturates in their diet for their beauty's sake. Unsaturated fatty acids are an important constituent of skin and muscle tissue and so it was thought, quite wrongly, that we need more of them. For what we have not been told is that the chemical structure of unsaturated fats with their free carbon atoms makes them extremely unstable compounds, and that when an unsaturated fat is exposed even to the smallest trace of a catalytic agent it begins a process of autooxidation which results in the fat molecule's breaking down to produce what are known as free radicals.

Free radicals are highly reactive particles which, if left unchecked in the presence of oxygen molecules, will form toxic peroxides. These peroxides can damage and destroy cells. They have also been implicated as a primary cause of the aging process itself. When a cell, or the genetic material of a cell, is destroyed by free radicals, the result is something known as a lipofuscin pigment granule—often referred to by biochemists as a "clinker." With age, ever more cells are damaged or destroyed as tissue degenerates, leading to increase in the number of these pigment granules. This is something you want to avoid in every way you can if you don't want to look and be old before your time.

To some extent, the presence of sufficient amounts of an antioxidant such as vitamin E in the system may prevent this from happening, because it minimizes the damage done by free radical chain reactions by breaking the chain. Vitamin E, like other antioxidants, helps block the oxidation that turns fatty acids into harmful peroxides. The more unsaturated fatty acids in your diet, the greater will be your need for the vitamin.

An interesting dietary survey that was done at the University of California at Irvine looked at over 1,000 patients and examined the degree of wrinkling and crow's-feet, frown lines, and other indications of skin degeneration such as damage to the collagen and elastin fibers and the irregular pigmentation characteristic of old skin. The subjects ranged in age from seventeen to eighty-one and 76 percent of them were women. Cadvan Griffiths, M.D., the professor of surgery who carried out the study, discovered that there is an undeniable link between marked clinical signs of aging and the intake of unsaturated fats in one's diet. Those who regularly and frequently included polyunsaturated fats and oils in their diet had marked signs of premature aging. Some looked as much as twenty years older than they were. Very few of those who had made no special effort to eat more polyunsaturates showed any clinical signs of premature aging. Evidence is also accumulating that links free radical reactions to the etiology of cancer, senility, atherosclerosis and hypertension—all of them disorders generally associated with aging. This is all the more reason to limit the amount of every kind of fat you eat to no more than you actually need.

Essential Fatty Acids

Another benefit you receive from eating fats is that they supply your body with essential fatty acids. They are known as the omegas: Omega 9 (oleic acid), Omega 6 (linoleic acid, or gamma-linolenic acid) and Omega 3 (alpha linolenic acid). These little beauties play an essential role in your health: they protect your immunity, have an anti-inflammatory effect and play a vital part in all your cell structure.

(You are what you eat, even if you are a cow! Studies show that grain-fed beef, such as American or European beef, has an imbalance in omega oils, unlike pasture- (grass-) fed beef, which we mostly have in New Zealand, and which contains a more natural ratio of omegas.)

In researching the omegas we were faced with endless data on the importance of the balance between these three fats. It seems that the modern diet supplies us with an overwhelming amount of Omega 6 oils, whereas the Omega 9 and Omega 3 oils are much lower down the scale. Omega 3 oils go rancid quickly, which is why industry avoids or modifies them — hence the lack of them in all processed foods. And like anything in nature, when you isolate a nutrient that is meant to work in harmony with others, you run the risk of increasing your susceptibility to ill health and disease. A healthy balance is what you should try to achieve.

You can get Omega 3 from such foods as fish (particularly oily fish like salmon, tuna, and sardines) and flaxseed oil. Omega 6 is found in vegetable oils, such as sunflower, safflower, corn, soybean and cottonseed oil, so we tend to get a fair amount of it in our normal diet. You can get Omega 9 out of olive and avocado oils.

Extra-virgin olive oil, which has been used for centuries, contains an excellent balance of all the omegas. Extra-virgin olive oil and all cold-pressed oils offer the best nutritional value when used raw and unheated. Use them as dressings over salads and vegetables, and dip your breads into the oil instead of using butter. If baking (cakes or biscuits) we prefer a cold-pressed unrefined oil with mild flavour like almond oil, or unsalted butter instead of margarine.

All cold-pressed oils start to oxidise (go off) from the moment they are pressed. This is the result of many factors, and is accelerated by exposure to air and light. It is better not to buy oil stored in plastic, as some plastics have the potential to be absorbed into the oil or leach chemicals. Glass is a better way to store your oil: ideally buy opaque or dark bottles, which block out the light. The ultimate way to buy your oil is in a tin, and many specialty stores sell cold-pressed oils this way.

High temperatures damage the essential fatty acids and destroy many valuable nutrients in your oil. The best ways to cook are therefore the ones using water, such as steaming, baking in a dish of water or blanching, because water cannot get any hotter than the boiling point of 100 degrees C. Frying, on the other hand, can induce extreme heat.

A good example of this is cooking fish. Salmon is a good source of Omega 3 fat and protein. When you cook it, you shouldn't fry it in oil over a high heat, or, heaven forbid, deep-fry it, because then you not only run the risk of destroying the essential fatty acids in the fish but also turning your oil into a trans fat due to the extreme heat. Cooking methods like steaming are healthier options. Boiling is also a water method, but be careful not to overboil, as you will leach out vitamins and minerals in the water.