Nutrition and Cancer Risk: Diets to Prevent Cancer

Cancer is a very complex topic because it’s features depend on which of the thousands of cell types in the body have mutated. The number of mutations (normally three or four to produce a cancer), and the actual location of the mutations, may also affect the characteristics of the cancer.

Studies have shown that at least 85% of cancers are environmental. In other words, they could have been prevented by reducing exposure to the cancer-causing agent or having a strong immune system that could stop the cancer in its early stages.

Smoking is the greatest environmental cause of cancers, accounting for a full 30% of all cancer deaths. So please stop smoking, and then cut your risk further with the following information.

Exercise and Weight

A great way to improve the immune system is by regular exercise; 30 minutes a day appears to be sufficient. Most cancer rates decline, and breast cancer growth slows. Prostate cancer risk is four times lower in fit men.

Another way to improve the immune system is to lose weight. The obese are five times more likely to develop colorectal cancer than healthy weight women. Obese women have three times the risk of endometrial cancer. Esophageal cancer risk is three and a half times more common in obese people. And adult leukemia risk is double in overweight women.

Cancer and Nutrition

A large part of cancer prevention involves what we eat. Great nutrition not only prevents the cancer-causing mutations, or helps to repair the damage, but also keeps our Natural Killer Cells operating properly to protect us.  These NK cells seek out changed or cancerous cells and kill them.

After many years of positive research results from taking vitamins, several recent studies found a daily multivitamin may increase cancer risk. This may be due to many vitamins being taken by men to try to cover for a very bad diet. If you choose to cut back on multivitamins, at least supplement with folic acid and Vitamin D, both of which are generally quite low in our bodies.

To understand the impact of nutrition on cancer, we need to focus on specific foods (e.g. broccoli) with known cancer-reducing properties (like fiber or calcium). For example, simply having two servings of fruit a day cut the risk of some cancers by 70% over those not eating fruit. Having five servings of fruit and vegetables daily reduced breast cancer by 36%.

Some findings about cancer-fighting nutrients:

  1. Calcium is an important mineral that can reduce colon cancer risk by almost half. It appears best to get calcium from at least two good sources daily, such as yogurt and a calcium supplement. But prostate cancer risk rises in men with high calcium intake.
  2. Fiber from most plant sources appears to lower the risk of developing colorectal cancers by over one third. Whole grains, nuts, vegetables and fruits are all recommended and all should be eaten every day.
  3. Folic Acid (or Folate) is a B vitamin that not only prevents birth defects, and helps brain function, but it can also lower the risk of breast cancers by over 25%. In women it cut pancreatic cancers by 75%. Folic acid is found in oranges and orange juice, and in many fruits and vegetables.
  4. Magnesium can reduce colon cancer risk by over 40%. Good sources include turkey breast, nuts, avocados, peas, beans and tofu.
  5. Multivitamins alone reduce colon cancer risk. Folic acid, Vitamin D, and selenium together block harmful chemicals. Vitamin D also helps the absorption of calcium.
  6. Omega-3 fatty acids appear to lower colon cancer risk by over 75%. Fish and fish oil are great sources, but plant sources such as walnuts and flax seed are also excellent. They may also reduce the risk for skin and prostate cancer.
  7. Selenium is a frequently overlooked mineral. A forty percent reduction in colorectal cancers occurred for those with high selenium blood levels. Amazingly, prostate cancer risk dropped 92% in those receiving supplements. Oysters, clams, lobster, and shrimp have high selenium levels. One Brazil nut contains approximately one daily dose. Just be careful not to increase the level too high; it can increase cancer risk!
  8. Vitamin A and beta carotene have been effective in reducing skin cancer. Individuals with the highest levels of carotenoids (i.e. beta carotene, lycopene from tomatoes) showed a six-times lower rate of skin cancer.
  9. Vitamin C appears to help reduce the incidence of the stomach bacteria (Helicobacter pylori) that triggers stomach cancer.
  10. Vitamin D is an interesting nutrient in that it improves the survival rate from melanoma, but it also seems to reduce the likelihood of getting non-Hodgkin’s lymphoma, breast, ovarian, prostate, and colon cancer. Part of its effect may be to help improve the absorption of calcium. Ten to fifteen minutes of sun exposure a day is a way to produce the vitamin D needed by the body.
  11. Acai in test tube studies was shown to kill leukemia cells.
  12. Apples can lower the risk of lung cancer by 50%. The active ingredient, quercetin, also occurs in onions. Higher levels are found in yellow onions than in milder white onions.
  13. Bananas, when eaten at least four times a week, reduced kidney cancer rates by half.
  14. Beans need to be eaten at least twice a week, preferably more, as they can reduce the risk of breast cancer. Colorectal cancers are also reduced due to fiber. An almost 50% drop occurred in lung cancer risk in those who ate the most beans, including estrogen-rich soy.
  15. Black tea reduced ovarian cancer by almost half in women who drank two cups daily.
  16. Blueberries have been shown to reduce the incidence of precancerous colon lesions. Their high Vitamin C also seems to reduce oral lesions by half.
  17. Broccoli and its relatives (cauliflower, cabbage, brussel sprouts, and broccoli sprouts) have great anti-cancer properties. Lycopene from tomatoes appears to make the broccoli even more effective because it causes a synergistic effect. Selenium-rich sunflower seeds, brazil nuts, and mushrooms have a similar effect. Steaming broccoli for three to four minutes enhances the cancer-fighting compound called suforaphane. Microwaving and boiling reduce this important antioxidant.
  18. Carrots help reduce the risk of kidney cancer. Beta carotene from carrots, pumpkins, squash, sweet potatoes, and oranges have been shown to reduce risk of lung cancer by 30% in women. A 43% decrease in breast cancer was found in those eating recommended daily amounts of yellow-orange-red vegetables, and over 50% risk dropped away for ovarian and pancreatic cancers.
  19. Coffee, at least the decaf variety, has been shown to drop the risk of rectal cancer by 50%. Regular coffee can help prevent skin, breast, endometrial, and lung cancers.
  20. Garlic is a good cancer fighter. If you are going to cook it, it is best to chop it up and then let it sit for 10 minutes so the helpful compounds are able to survive the heating.
  21. Green tea has polyphenols which lower the risk of prostate cancer, and cuts ovarian cancer risk in half. Women have a 75% decrease in stomach cancer risk, while the risk in men might increase.
  22. Lemon or lime peels help reduce skin cancer risk by one third. Orange or grapefruit peels in marmalade had a similar effect. Tangerine peel might help fight breast, lung, and prostate cancers.
  23. Pomegranate juice has been shown to slow prostate and lung cancer growth.
  24. Seaweed has been shown to lower skin cancer risk by 60%.
  25. Soy beans and soy products appear to lower prostate cancer risk.
  26. Spinach and other dark green leafy greens are high in folic acid which can help reduce the chances of getting breast, colorectal, and ovarian cancer. These and kale, along with green peppers also reduced the incidence of cervical cancer.
  27. Tomatoes and watermelon contain lycopene which has anti-cancer properties. Prostate cancer risk declined almost 30% in men who ate tomatoes at least twice a week. Skin and colon cancers declined by 40%. The orange varieties of tomatoes are as high in lycopene as are cooked tomato sauces. Organic ketchup has much higher levels of lycopene than regular ketchup varieties. It has also been found that eating broccoli in the same meal as tomatoes synergizes the lycopene and thus provides extra protection.
  28. Whole grains reduce both the risk of colon cancer and of breast cancer. Brown (whole) rice works this magic by the bran carrying the mutation-causing poisons out of the digestive system.

Foods to Avoid

Hot dogs, sausage and other processed meats increase the risk for pancreatic cancer, which is almost always fatal. A daily dose of processed meats increases cancer risk by two-thirds.

Sugar and starch are both known to increase blood sugar levels and can lead to the development of Type II diabetes. It is now known that diabetes itself is a risk factor in cancers. Be cautious about ingesting too many simple carbs. Avoid sugar, corn syrups, starchy foods, white bread, white rice, and white pastas to keep blood sugar levels under control.

Pickled foods increase the risk of stomach cancers.

Trans fats (hydrogenated and partially hydrogenated oils) and probably saturated fats increase the incidence of prostate cancer. Those who eat the most red meat increase their risk of colon and rectal cancers by 40%, and breast and ovarian cancer risk grows 20%.

Eating more than four slices of white bread a day doubles the risk of developing kidney cancer.

Published by on June 25th, 2008 tagged Disease Prevention

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