FATS & FACTS

by Dr. Rallie McAllister

Dietary fat has gotten a bad rap lately. With the increasing popularity of low-fat and no-fat diets, Americans have developed an unhealthy degree of fat phobia.
For decades, doctors have been treating patients suffering the consequences of consuming too much fat. High-fat diets are known to contribute to dozens of medical maladies, including obesity, high cholesterol levels and heart disease. Recently, however, physicians have begun to see a rise in the number of people who are suffering the negative effects of extremely low-fat diets.

Contrary to popular belief, some forms of dietary fat are not only beneficial; they're absolutely essential. High-quality fats help promote good health and ward off a variety of diseases. Of the three main types of dietary fat, polyunsaturated, monounsaturated and saturated, the polyunsaturated fats are considered to be the most beneficial.
Saturated fats are the bad guys. They usually exist in the solid form at room temperature, and they're derived mainly from animal sources like meats and dairy products.

Some plant oils, including palm oil and coconut oil, are also saturated, and they're just as bad for you as animal fats. These fats are often hidden in snack foods like cookies, cakes and some types of chocolate. Eating too many saturated fats can elevate your cholesterol levels, leading to clogged arteries and eventually, to heart disease.
Polyunsaturated fats are the good fats. They're liquids at room temperature, and can be found in some plant oils, like sunflower, safflower, soybean and sesame seed oil. These friendly fats are also found in cold water fish; including tuna, halibut, herring, sardines and salmon. Polyunsaturated oils contain health-promoting substances called essential fatty acids, or EFAs. Because the human body isn't capable of manufacturing these substances, they must be consumed in the diet.

Some nutrition experts estimate that roughly 80 percent of U.S. adults consume diets that are deficient in essential fatty acids. Highly processed convenience foods, which make up a large part of the typical American diet, are deliberately stripped of many EFAs to prolong their shelf life.

Diets that are lacking in essential fatty acids can promote or worsen many medical conditions, including diabetes, arthritis and skin disorders like psoriasis and eczema. Inadequate consumption of these health-promoting substances can aggravate premenstrual syndrome, emotional disorders and menopausal symptoms.

Recent research suggests that diets rich in EFAs may help strengthen bones and prevent osteoporosis. Essential fatty acids have been shown to increase calcium absorption from the intestines while reducing excretion of the mineral through the urinary tract.

The essential fatty acids found in fish oils may play an important role in the reduction of breast cancer risk. This protective effect was first observed in Greenland Eskimo women, who thrive on fished-based diets and have extremely low rates of breast cancer.

Essential fatty acids play an important role in pregnancy, promoting normal growth of tissues and organs in the developing fetus. Maternal diets that are deficient in EFAs have been linked to low birth weights and poorly developed central nervous systems in newborns.

Essential fatty acids seem to alleviate many symptoms associated with premenstrual syndrome, including mood swings and bloating. One study found that in women taking fish oil supplements, 73 percent reported a welcome reduction in painful menstrual cramps.

While diets high in cholesterol and saturated fats are known to contribute to heart disease, diets rich in EFAs have been shown to reduce the risk. The substances seem to help prevent blood clots in the heart's arteries, decrease inflammation in blood vessel walls, and support a regular heart rhythm. Several studies suggest that diets rich in EFAs help lower blood pressure and cholesterol levels.

At a recent conference sponsored by the American College of Cardiology, scientists touted the heart-healthy benefits of the essential fatty acids found in fish oils. In a study involving more than 11,000 volunteers with heart disease, those taking daily fish oil capsules enjoyed a 10 percent drop in the number of heart attacks and a 45 percent reduction in sudden cardiac death.

Diets rich in essential fatty acids also appear to help lower the risk of stroke. Results from the Nurses' Health Study, which followed nearly 80,000 women for 14 years, found that those women who ate the most fish had the fewest strokes.

If you're trying to cut down on your fat consumption, your best bet is to avoid fast food and junk food. But don't let fat-phobia cause you to miss out on the friendly fats that are vital to your good health.

Rallie McAllister, M.D., M.P.H., is a family physician in Kingsport, Tenn. Her Web site is at http://www.rallieonhealth.com