By David Liu PHD

saturday May 19, 2012 (foodconsumer.org) -- An article released in the Journal of Internal Medicine says different types of dietary fats have different effects on the risk of coronary heart disease, which is the major heart disease and a leading killer in the United States.

Coronary heart disease also known as coronary artery disease is a condition in which the arteries are blocked by the plaque formed by a number of substances including cholesterol and calcium.

The report by Walter C. Willett MD, DrPH of Department of Nutrition, Harvard School of Public Health in Boston MA says all sorts of evidence indicate that specific types of dietary fatty acids play important roles in the cause and prevention of coronary heart disease, but total fat as a fraction of energy is not as relevant.

Dr. Willet says in his report that dietary trans fat or trans fatty acids found in partially hydrogenated vegetable oils have clear adverse effects and should be eliminated from a person's diet.  Harvard nutritionists and epidemiologists have estimated that as many as 100,000 deaths each year in the United States from heart disease have something to do with trans fat.

The Food and Drug Administration has required food manufacturers to label the level of trans fat in food.  But food processors are allowed to list a food as trans fat free if one serving of the food contains no more than 0.5 grams of trans fat.

Consumer advocates suggest that food consumers who are concerned about trans fats should not only read the nutrition fact table, but also the ingredient list.  If partially hydrogenated vegetable oils are present in  the ingredient list, then the food contains trans fat.  There is no safe threshold for trans fat. Any amount may boost the risk of coronary heart disease.

Food manufacturers have reduced their use of trans fat in processed foods. But the toxic fats are still commonly used in many processed foods.  Restaurant-reserved foods can contain high levels of trans fat although many fast food chain restaurants such as Wendys, McDonalds, and Pizza Hut claim they stop using trans fat in all except a few foods.

Dr. Willet also reports that reduced intake of saturated fat may possibly moderately cut the risk of coronary heart disease if saturated fat is replaced by a combination of poly-and unsaturated fat, particularly the former.

It seems though that when saturated fat is replaced by carbohydrates, the benefits are not apparent.  But again it all depends on what types of carbohydrates are used to replace saturated fat.  

Cornell University nutritionist Dr. Colin T. Campbell says in his book China Study that plant-based diets including foods like grain products can reduce risk of coronary heart disease.  Not all types of carbohydrates are bad.  Starch and particularly fiber are good while added sugars and high fructose corn syrup are considered unhealthy. Patients with coronary heart disease using plant-based diets reverse or at least stopprogression of their condition in 99 percent of the cases.

Other types of fats omega-3 and omega 6 polyunsaturated fatty acids are essential and they can help reduce the risk of heart disease, according to the author.  Caution needs to be exercised though that intake of too much of any fat or oil like n-6 or n-3 fat can be bad. The best sources for these oils are foods which are high in these types of fats including nuts and cold water fish.

The author says in his report "In practice, reducing red meat and dairy products in a food supply and increasing intakes of nuts, fish, soy products, and nonhydrogenated vegetable oils will improve the mix of fatty acids and have a markedly beneficial effect on rates of coronary heart disease."