Fat is also required in order to absorb the fat-soluble vitamins A, D, E and K which are essential for proper function of your eyes, immune system, and bones. But the important thing to remember is, not all fats are created equal. In fact, some fats can harm while other fats can heal.

Saturated fat

Controlled clinical studies, plus large population studies, have repeatedly shown that if we consume too much saturated fat (found in high amounts in red meat and dairy products) it can lead to elevated levels of potentially harmful low-density lipoprotein (LDL) cholesterol in the blood. Our bodies are ill-equipped to deal with large amounts of LDL cholesterol in the blood, and the excess can accumulate on the walls of our arteries. This can lead to a plaque forming, and a hardening and narrowing of the arteries, or what is known as atherosclerosis.

Atherosclerosis displays no symptoms as it gradually restricts blood flow. Eventually this can end up causing a clot (thrombus), completely blocking an artery that feeds blood to a vital organ. Ultimately this can lead to a heart attack if a coronary artery is blocked, stroke if an artery to the brain is blocked, or kidney failure if an artery to the kidney is blocked.

Trans fat

Another type of fat that can be harmful to your health if consumed in excess is called trans fatty acids or trans fat. Trans fat is formed when liquid vegetable oils are hardened ("hydrogenated") to make shortening and margarine.

Although hydrogenated oils have some advantages over normal vegetable oils—namely they have a longer shelf life and can be heated to higher temperatures—studies have shown that the trans fat formed by hydrogenation raises levels of bad LDL cholesterol, lowers good HDL cholesterol and raises triglycerides (blood fats)—all known risk factors for heart disease.

A typical Western diet is generally very high in trans fat because margarine has become increasingly popular and hydrogenated vegetable oils (such as vegetable shortening) are used in everything from commercially produced cookies, crackers, pies and pastries, to fried snack foods like potato chips, and foods fried in fast-food outlets (such as French fries).

Unsaturated fats

Unlike saturated fat and trans fat which raise LDL cholesterol levels in the blood, unsaturated fats (monounsaturated and polyunsaturated fat), which are found in high amounts in plant and fish oils, have been shown to lower it.

Monounsaturated fat (the principal source of fat in olives and olive oil, peanut oil, canola oil, avocados and certain nuts) is particularly healthful because it lowers LDL cholesterol without affecting good HDL cholesterol.

In one study, researchers from the Pennsylvania State University and the University of Rochester in New York, found that when 22 subjects consumed a diet that was rich in monounsaturated fat from olive oil, peanuts and peanut oil, their LDL cholesterol levels dropped by an average of 14 percent in four weeks. At the same time, there was no change in heart protective HDL cholesterol levels. “These results show that eating more monounsaturated fat can reduce your heart-disease risk by 25 percent,” reported the study author professor Penny Kris-Etherton.

Studies have also shown that monounsaturated fat can help control high blood pressure, lower the risk of stroke and can help assist brain function into old age. Monounsaturated fat, along with polyunsaturated fat, is also a good source of vitamin E, a powerful antioxidant.

Omega-3 fat, which is a type of polyunsaturated fat, comes with a myriad of its own health benefits, see Eat fish and shellfish regularly.

Here are some effective ways of reducing your intake of bad fats while increasing your intake of good fats: Instead of making red meat the main source of protein in your diet, opt for fish, shellfish, poultry, legumes and nuts. Make olive, peanut and canola (rapeseed) oils your main cooking fats. These oils are all rich in heart-healthy monounsaturated fat. Eat less trans fat packed snacks like potato chips, cookies and pastries, and eat more nuts (such as walnuts, cashews, almonds and pistachios) which are rich in vitamins, minerals, fiber and healthy unsaturated fats. Just keep in mind that nuts still contain a fair amount of calories. An ounce, which is about a handful, provides between 165 to 200 calories (depending on the type of nut). So the idea is to enjoy nuts regularly, but in moderation, and particularly as a substitute for less wholesome snacks. Instead of spreading bread with butter or margarine use avocado, hummus, natural peanut butter or trans fat free margarine. Do as Mediterranean cultures traditionally have done and consume dairy products regularly, but in small amounts (more as a condiment), opting mostly for cheese and yogurt. Soy milk can be substituted for cow's milk. Enjoy eggs in moderation (around 4-7 a week).   < Back | Main | Next >