Health: Foods that prevent cancer

By Cynthia Ross Cravit, 50Plus.com

Cancer is no longer thought to be solely the product of factors outside of our control such as heredity or accidental contact with toxic pollutants. In fact, scientists believe there is a great deal we can do to reduce our risk of developing the disease.

The 2007 Expert Report by the World Cancer Research Fund (WCRF) found that the food we eat and other lifestyle choices such as daily physical activity and maintaining a healthy body weight are key to preventing cancer. This epic report - which was five years in the making and reviewed 7,000 large-scale studies - found that an unhealthy diet is linked to about one third of all cancer cases.

In fact, according to U.S.-based The National Cancer Institute (NCI), serious diseases that are linked to what we eat kill an estimated three out of four Americans each year. These diseases include heart disease, high blood pressure, stroke, diabetes and some types of cancer.

But while the foods you eat can hurt you, they can also help you. And not surprisingly, fruits and vegetables are "All-Star foods" when it comes to protecting yourself against cancer.

Foods you gotta love

Research shows that diets most protective against cancer are predominately plant-based. Here are just a few ways food can help in the battle against cancer.

Cruciferous vegetables (broccoli, cauliflower, kale, Brussels sprouts, bok choy, kale) contain two antioxidants, lutein and zeaxanthin that may help decrease prostate and other cancers.

Foods that contain folate such as liver, spinach, beans, broccoli, oranges, lettuce, avocado, and asparagus are thought to help protect against cancer of the pancreas. Avocados are also rich in glutathione, a powerful antioxidant that attacks free radicals in the body. They also provide even more potassium than bananas.

Onions, chives, leeks and garlic may help prevent stomach cancer. Garlic also has immune-enhancing allium compounds that appear to increase the activity of immune cells that fight cancer.

The beta carotene found in carrots may help reduce a wide range of cancers including lung, mouth, throat, stomach, intestine, bladder, prostate and breast. (Some research suggests beta carotene may actually cause cancer, but it has not proven that eating carrots, unless in very large quantities - 2 to 3 kilos a day - can cause cancer.) Sweet potatoes also contain many anticancer properties, including beta-carotene.

Certain types of mushrooms such as Shitake, maitake, and reishi are thought to help build the immune system and prevent cancer cells from multiplying.

Fruits are also thought to provide protection against cancer. Grapefruits, like other citrus fruits, help to rid the body of carcinogens. Red grapes contain bioflavonoids, powerful antioxidants that work as cancer preventives. Like red wine, they are also a rich source of resveratrol, which inhibits the enzymes that can stimulate cancer-cell growth. Papayas are thought to reduce absorption of cancer-causing nitrosamines from the soil or processed foods. Raspberries, blueberries and strawberries are also thought to contain many cancer preventing properties.

Tomatoes contain lycopene, an antioxidant that attacks the free radicals that are suspected of triggering cancer.

Selenium, a mineral found in brazil nuts, sunflower seeds and fish is thought to provide protection against prostate cancer.

Tip: To eat healthfully, experts say a good rule of thumb is to fill 2/3 of your plate with vegetables, fruits, whole grains and beans and 1/3 or less with animal foods. Look for recipes for casseroles, stews and stir fries that use meat almost as a condiment.

Foods to avoid

Now for the bad news, particularly for meat-lovers. To maintain a healthy diet, you can forget about eating processed meats such as bacon, ham, salami, corned beef and some sausages. According to the WCRF, no amount is considered completely safe. Also try to limit consumption of red meats (such as beef, pork and lamb) to less than 500g cooked weight (about 700-750g raw weight) a week. Both red and processed meats are thought to be causes of bowel cancer.

Tip: For big breakfast eaters, try having your eggs with roasted tomatoes, which are rich in healthy carotenoids - which the WCRF says can lower the risk of cancers of the mouth, pharynx, larynx and lung. And add some crushed garlic to help prevent bowel and stomach cancer. Tasty and healthy substitutes for bacon (particularly in pasta sauces) are cooked mushrooms because of their strong flavour and meaty texture.

Other 'bad guys'

Salty foods and foods processed with salt, including some bread and breakfast cereals. Research suggests that salt and salt-preserved foods are linked with stomach cancer.

Alcohol consumption is linked to an increased risk of cancer of the mouth, throat, larynx, esophagus, breast, and liver. Experts advise drinking alcohol only moderately, which for men means no more than 2 drinks a day and for women, only one per day. (Examples of what is considered one drink: 5 ounces of wine, 12 ounces of beer, 1.5 ounces of 80-proof liquor.)

Sugary drinks and energy-dense foods (high in fats and/or sugars and often low in nutrients and fiber) increase the risk of obesity - and therefore, cancer. Scientists have found that greater body fat increases the risk of cancer of the esophagus, pancreas, colon and rectum, breast (postmenopausal), kidney and gallbladder cancer.

Reduce your cancer risk

When it comes to eating to prevent cancer, Liz Armstrong, co-author of Cancer: 101 Solutions to a preventable epidemic (New Society Publishers), says there are 4 'must do' principles to reduce your cancer risk.

1. Eat abundance of fruits and vegetables - and as much as possible, buy fresh, ripe, locally grown and organic. As a general rule of thumb: raw or lightly steamed is more healthy than cooked; fresh is better than frozen; and frozen is better than canned.

2. Drink lots of healthy liquids including pure water (cleansed of chlorine and other contaminants), various teas such as green and Chai, and freshly juiced fruits and vegetables.

3. Start your cancer prevention early - in the womb if possible! The good news, however, is that it's never too late to begin. "While starting 'in utero' is not an option for us over-50s, we can offer this good advice to our kids and grandkids who are about to become pregnant," Armstrong says.

4. Take good quality food supplements. While the WCRF recommends that people aim to meet their nutritional needs through food, Armstrong says this is not always possible - and not only because of our busy schedules. "We know from the literature and studies of food nutrients over time that the percentages of many vitamins and minerals in veggies have plunged since the 1930s and 40s, so it seems prudent to supplement, that is, until the soils that grow most of our foods have been remediated sufficiently to provide what our bodies need," Armstrong says.

A caveat: Not all vitamin supplements are created equal and there is much controversy about recommended dosage. Research has shown that high doses of nutrient supplements can both protect against and cause cancer. Because of this, Armstrong recommends consulting with your doctor or a nutritionist before supplementing. For more information on vitamin supplements, click here.

Cancer facts from the World Health Organization

-- Cancer is a leading cause of death worldwide. There are more than 100 types of cancers; any part of the body can be affected.
-- In 2005, 7.6 million people died of cancer. This represents 13 per cent of all deaths.
-- Worldwide, the 5 most common types of cancer that affect men are (in order of number of global deaths): lung, stomach, liver, colorectal, oesophageal and prostate.
-- Worldwide, the 5 most common types of cancer that affect women are (in order of global deaths): breast, lung, stomach, colorectal and cervical.
-- Tobacco use is the single largest preventable cause of cancer in the world.
-- 40 per cent of cancer can be prevented by having a healthy diet, being physically active, and not smoking.

Sources: World Cancer Research Fund; American Institute for Cancer Research; World Health Organization; WCRK UK

ON THE WEB: For more on protecting yourself from cancer, click here (pdf file). For healthy recipe ideas, click here.