Monday, May 30, 2005
foods versus cancers
Almost everyone has been touched by cancer, either personally or by watching a loved one's battle. According to the Canadian Cancer Society (CCS), cancer is the leading cause of premature death among Canadians, claiming more than 68,000 lives in 2004.
Researchers have linked about one-third of cancer deaths to dietary factors, such as those that contribute to obesity, according to the CCS.
Research has shown that people whose diets are rich in plant-based foods — fruits, vegetables and whole-grain breads and cereals — have a lower incidence of most cancers. Why? While researchers are still searching for the answers, it appears that plant foods — particularly produce items — are rich in antioxidants and phytochemicals.
According to the CCS, antioxidants protect cells from DNA damage that can be caused by very unstable forms of highly reactive molecules called free radicals.
Beta carotene (a substance converted into vitamin A) and vitamins C and E — the "ACE vitamins" — are particularly potent antioxidants that may offer protective benefits for some cancers. However more research needs to be done in the area of antioxidants — particularly when they are taken in the form of dietary supplements — to assess which antioxidants protect against which cancer. In fact, large amounts of some antioxidants may actually promote certain types of cancer (for example, beta-carotene has been linked with lung cancer.) At present, research is strongest in the area of vitamin E and prevention of colorectal cancer.
Why the Mediterranean Way Works
The Mediterranean diet may offer some cancer-protection properties — it is rich in fruit and vegetables and high in monounsaturated rather than saturated fat, which has been linked to increased risk for many cancers. Some scientists have even speculated that Mediterranean people's love affair with tomatoes may play a part in their relative good health, because tomatoes are high in the powerful antioxidant lycopene.
There are, however, thousands of phytochemicals (naturally occurring substances in plant foods), and we don't yet fully understand how they work or interact to prevent cancer. So rather than focusing on any one item, nutritionists recommend getting most of your nutrients through food rather than supplements, and eating in moderation from a wide variety of food groups, particularly grains, fruits and vegetables. Be sure to get the five servings of fruits and vegetables per day that Weight Watchers recommends.
Easy Ways to Eat Better
Alas, 80 percent of us don't consume anything close to five servings of fruits and veggies. How can you up your intake?
Favour dishes incorporating as many plant-based ingredients as possible — such as stir-fries, soups, salads and rice salads.
Snack on fruit.
Keep crunchy raw vegetables on hand, such as carrot sticks, jicama and pepper strips.
Add leafy greens such as spinach leaves and watercress to sandwiches.
Consider nutrient-rich squashes as side dishes.
Top cereal and salads with fruit, nuts, sesame seeds or pumpkin seeds.
Empty a can of beans or tomatoes into your favourite casserole.
When shopping, select items such as multigrain bread, dried fruit salad or mixed frozen vegetables.
Anti-Cancer Eating Plan in a Nutshell
According to the Canadian Cancer Society, you may reduce your risk of cancer by:
Choosing most of your food from plant sources.
Increasing your fibre intake to 25 to 35 grams per day. Whole grains, fruit and vegetables are particularly rich sources of fibre.
Reducing your fat intake to 30 percent of daily calories and choosing monounsaturated fats as often as possible. Fat — particularly saturated fat — increases the risk of colon and prostate cancers.
Eating less meat. Over-consumption of red meat (beef, pork, lamb) may raise the risk of colon and prostate cancer.
Cutting back on salt-cured, pickled and smoked foods, which are implicated in cancer of the stomach and esophagus.
Limiting alcohol to one or two drinks a day, at most. Overindulgence in alcohol has been associated with an increased risk of cancer of the liver, breast, throat, esophagus and larynx.
Maintaining a healthy weight. Obesity is a risk factor for several cancers; losing weight reduces that risk.
Seeking ACEs in All the Right Places
The most studied antioxidants are the ACE vitamins:
Beta carotene: Converted to vitamin A in the body, beta carotene is found in orange vegetables and fruits (carrots, sweet potatoes, pumpkins, squash, cantaloupes, apricots, peaches, mangoes and papaya) and in dark-green leafy vegetables, such as spinach, parsley, kale and chicory. Beta carotene is part of the carotenoid group, the name given to more than 600 different pigments found in fresh produce. Others include lycopene (responsible for the red colouring of tomatoes, watermelons and pink grapefruit), and lutein (present in dark-green leafy vegetables and some yellow vegetables).
Vitamin C: Found in citrus fruits, rosehips, cantaloupe, strawberries, kiwifruit, pineapples, tomatoes, potatoes, dark leafy greens, red and green peppers, broccoli and Brussels sprouts.
Vitamin E: Found in avocados, whole grains, nuts, seeds, wheat germ and vegetable oils.