Foods that harm, foods that heal: cardiovascular disease

Diet and cardiovascular health often go hand in hand. The following information details the strong link between the two and suggests ways to maintain a heart-healthy diet.

Excessive cholesterol circulating in the blood is the major precipitating factor in atherosclerosis. Most often, high cholesterol is caused by diet, lack of exercise and other lifestyle habits.

For most people, moderately elevated cholesterol levels can be lowered by adopting a diet with less than 30 percent (but preferably 20 percent) of its calories coming from fats, mostly the monounsaturat­ed and polyunsaturated types found in plant oils, fish, nuts and seeds.

Doctors have traditionally advised using margarine, especially the kinds made with corn, safflower and other unsaturated fats, instead of butter. But the trans fatty acids in hardened margarine may raise LDL cholesterol levels even more than butter's mostly saturated fat does. A soft margarine made from non-hydro­genated fats is probably the best choice. Several such brands are now available.

Although observational studies suggest that antioxidants from food sources play a protective role against cardiovascular disease, studies using supplements have proved disappointing. One trial found no significant benefits from taking daily supplements of vitamin E, beta-carotene and vitamin C in people at high risk. And the relationship between vitamin E and prevention of heart disease is still not resolved. Some research has even shown that antioxidant supplements may reduce the efficacy of the "statin" type cholesterol lowering drugs.

Some studies show that high doses of beta-carotene may help reduce the risk of cardiovascular disease by about 45 percent. Carrots are one of the richest sources of this important carotenoid. However, studies also indicate that high doses of beta-carotene in pill form will not help prevent heart disease.

A group of researchers in Finland identified excessive iron as another dietary factor that may well damage the heart and blood vessels. While it was already well known that excessive iron damages the heart, liver and other vital organs, this was the first time that iron levels in the high–normal range were linked to a serious health risk. It reinforces the long-standing advice not to take any supplements without first consulting a doctor.

Twenty-five percent of North Americans dying from cardiovascular diseases don't have high blood pressure or high LDL cholesterol; they don't smoke and aren't excessively overweight. High levels of homocysteines in the blood may be the culprit. Homocysteine is an amino acid known to damage the walls of an artery when it reaches high concentrations in the blood.

Eat plenty of:

• Fresh fruits and vegetables, foods rich in vitamin C, beta-carotene and other antioxidant nutrients.
• Fish.
• Soy protein.
• Apples, oat bran and other soluble fibre foods.
• Whole-grain breads and cereals.
• Nuts.

Limit:

• Saturated fats in fatty meats, chicken skin, full-fat dairy products, coconut oil and lard.
• Eggs, whole milk, organ meats and other high-cholesterol foods.
• Fats, especially those that are saturated.
• Trans fatty acids found in partially hydrogenated margarine and shortenings, processed foods made with partially hydrogenated fats and baked goods.

Avoid:

• Excessive alcohol.
• Tobacco use in any form.
• Salty foods (if you have hypertension).