Antioxidants cut free radical risk
by Dr. Bhiku Jethalal
Despite advice from dietitians, two-thirds of all deaths in the West are due to heart disease and cancer, both linked to our 20th century lifestyles.
Many people ask about vitamins as a defence. Reports about anti-oxidant vitamins, particularly beta carotene and vitamin E, have been confusing.
Before we can understand the role of these vitamins, we need to understand the concept of free radicals - potential factors in many illnesses. Free radicals are unstable molecules, with one of their many pairs of electrons missing an electron. This free radical goes on a "search and destroy" mission, stealing an electron from a healthy molecule.
A low-fat, vegetarian diet would cause the least amount of free radical damage.
Scientific research now confirms that free radicals play a major role in the development of cancer, heart disease, aging, cataracts and impairment of the immune system. They are seen as molecular loose cannons involved in biological fireworks.
Free radicals are impossible to avoid. Even our own bodies produce them as a byproduct of normal metabolism. But a vegetarian diet is low in the oxidants - dietary fat and iron - that cause your body to produce free radicals. Animal products, especially red meat, contain the highest amount of these substances. Therefore, a low-fat, vegetarian diet would cause the least amount of free radical damage.
Our body is bombarded by millions of free radicals daily. Cooked red meat contains nitrates, which combine with by-products of protein in the meat to form hetrocyclic amines. These compounds can cause cancer. And a US National Cancer Institute report last year shows that oven-broiled, pan-fried or grilled/barbecued chicken contains much more of these carcinogens than a well-done hamburger or grilled steak.
But all is not lost. It is now well-recognized that antioxidants can neutralize free radicals.
The body makes enzymes that curtail some free radicals. The mineral selenium also has antioxidant properties. But the three main outside sources of anti-oxidants are beta carotene, vitamin C and vitamin E.
Beta carotene, a yellow-orange pigment found in plant foods, tops the list of the 400-member family known as carotenoids, the ultimate source of vitamin A.
Carotenoids can be found in most yellow-orange, dark-green leafy vegetables and fruits such as kale, romaine lettuce, beet greens, cassava, broccoli, carrots, mushrooms, pumpkins, spinach, yams, tomatoes, apricots, papaya, peaches, cantaloupe, coriander, basil and parsley.
Beta carotene requirements may rise if you smoke, consume alcohol, are regularly exposed to ultraviolet light or take the birth control pill.
Vitamin C: Recent studies have shown that vitamin C is associated with a decreased incidence of many types of cancer, especially those of the gastro-intestinal tract (mouth, throat, stomach, pancreas, colon and rectum). It has also been shown to decrease risk of breast, cervical and lung cancer.
Sources of vitamin C are citrus fruits and juices (including melons, strawberries, papaya, kiwis, mangoes, blackberries, raspberries, red and green peppers), cruciferous vegetables (broccoli, cauliflower, Brussels sprouts and cabbage), tomatoes, sweet potatoes and leafy greens.
Vitamin E is considered "the first-line defense" against cell membrane damage due to oxidation. Sources include vegetable oils, whole grains, fortified cereals, nuts, dark leafy greens (fresh spinach and kale), mangoes and wheat germ. Because some other foods rich in vitamin E are also high in fat (such as mayonnaise, peanut butter, avocados and shellfish), I recommend avoiding them.
This article appeared in the Toronto Star, July 4, 1996