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Cancer Prevention


You can make dietary and lifestyle choices which will reduce your chances of being the one out of three Canadians who will get cancer in their lifetim.

You can make dietary and lifestyle choices which will reduce your chances of being the one out of three Canadians who will get cancer in their lifetime.

While you cannot avoid every genetic risk, environmental insult, and the aging process, you may be able to delay or even avoid the diseases which kill two of every three Canadian adults. Bad things do sometimes happen to good people with good habits, but the choices that can help you avoid cancer - adding protective factors, reducing risky behaviours, and seeking early detection - may also help you avoid cardiovascular disease, diabetes, hypertension, and other chronic degenerative conditions.

Vegetables are Vital

Protection comes in many agreeable packages; delicious foods provide us with proven cancer fighters. Increasing the amount of fruits and vegetables you eat to over five servings daily adds protective ingredients such as antioxidants and bioflavonoids, resveratrol, limonene, lycopene, and polyphenols to your diet. A cancer-preventive diet includes two to three servings of fruit, four to six servings of vegetables, and more than seven servings of other plant foods such as whole-cereal grains, beans, peas, roots, and tubers daily. All the colours of the rainbow should be represented in the variety of foods you eat, but especially good cancer-fighting foods include blueberries, grapes, cherries, apples, tomatoes, celery, yams, squash, onions, and garlic.

Green vegetables and green drinks such as barley grass juice and wheat grass juice are sources of that "magical" capturer of all sun energy on this planet, chlorophyll. This green substance inhibits the leading trigger of skin cancers, lipid peroxidization. Green vegetables are also powerful detoxifiers of the blood. Plant fats such as sterols and sterolins, found in all fruits and vegetables, are being studied as immune modulators that may benefit cancer patients.

Folic acid (also known as folate), found in green leafy vegetables, is a significant regulator of cell development. The long-running Nurse's Health Study showed folate to work well as a protective factor against colorectal cancer. Both folate and vitamin B12 put methyl groups into DNA to silence overactive genes. A multivitamin with B-complex vitamins such as folate or a greens powder supplement should be included in a cancer-prevention diet, especially if you eat under five servings of vegetables daily.

The cabbage family of vegetables gives us indole-3-carbinol, which reduces the activity of potentially harmful hormones such as estrogen. Excess estrogen exposure is the primary cause of breast cancer, and sex hormones are also thought to contribute to prostate, colorectal, and other common cancers.

Cancer Fighters in Your Diet

Seeds and plants contain lignins, which friendly bacteria in our gut turn into weak phytoestrogens. These bind to estrogen receptors on cells and block the signal to grow. A good example of a seed with cancer-fighting lignins is flaxseed, which is antiestrogenic enough to be thought to play a role in preventing and treating hormone-dependent cancers. Its lignins also increase the liver's output of sex-hormone binding proteins, which further inactivate excess hormones.

Psyllium husks are converted by bacteria in the colon to short-chain fatty acids such as butyrates, which regulate the abnormal DNA in cancer cells. Flaxseed, hemp, nuts, seeds, seafood, fish, and fish oils are excellent sources of omega-3 fats, which reduce arachidonic acid and prostaglandin PGE2, associated with inflammation. Inflammation gives rise to a host of growth stimulators which can accelerate cancer.

Vitamin and Mineral Supplements

Calcium and vitamin D are being studied for their role in reducing risk of colorectal cancer. The best form of calcium is calcium-D-glucarate, which some researchers believe may be the most bioavailable. It is found in citrus fruit, cruciferous vegetables (cabbage family again), and apples. It inhibits beta-glucoronidase, an enzyme involved in metastasis in hormone-dependent cancers.

Vitamin D levels in Canadians are decreasing as more people avoid risk of skin cancers from the ultraviolet radiation in sun exposure. Vitamin D is a very good regulator of growth, helping to slow the growth and spread of cancers. Vitamin D in cod liver oil has been a proven immune stimulant in the dark winters of the northern latitudes for two hundred years. Cod liver oil also contains vitamin A, a primary cell-growth regulator and immune modulator and omega-3 fats EPA and DHA, also regulators of inflammation.

Some research has suggested that the mineral selenium, taken in moderate doses, reduces risk of many cancers by acting as an antioxidant. In one study, reported in the Journal of the American Medical Association (1996), doses of only 200 micrograms a day appeared to reduce skin-cancer risk by half. Studies also suggest selenium works very well with vitamin E to prevent cancer of the prostate, and the vast SELECT study (Selenium and Vitamin E Cancer Prevention Trial, run by the National Cancer Institute and launched in 2001) is now underway at over 400 sites in the United States, Puerto Rico, and Canada. The results from this study should give us a greater understanding of exactly how selenium works to fight cancer.

Green tea is rich in polyphenols, which appear to be able to suppress the growth of many cancers. The polyphenols in green tea inhibit cancer first by checking formation of new blood vessels into tumours and second by stopping their spread into other tissues. A protective or preventive amount of tea is 10 or more cups daily, and it would take over 40 cups daily to treat a tumour. In clinical applications, therefore, it is used as a polyphenol extract in capsule form in addition to being enjoyed as a beverage.

Avoiding Dietary Carcinogens

Unwanted and unintentional hormones (xenohormones) are found in nonorganic fruits and vegetables, animal feeds, and - due to agricultural runoff - our water supply. EPA studies showed dioxin, styrene, and other xenohormones in 100 percent of fat samples taken from human bodies in the USA. Endocrine disruptors such as the pesticide residue dioxin and the industrial pollutant methoxychlor attach to our estrogen receptors. To avoid these chemical hazards and suspected carcinogens chlorine and nitrates, it is best to choose purified water to drink and organic food to eat. Milk and cheese from organic-fed cows are increasingly available, as are free-range eggs and poultry, grass-fed red meats, and wild fish.

Eating red meat may increase your risk of cancer due to its saturated fat content, the toxins produced during grilling, and the presence in the meat of xenohormones given to the animals. Some studies indicate that vegetarian diets give a survival advantage for cancer. An excellent vegetarian source of protein, soy may also be a leading protective factor. While the research is not yet conclusive, soy isoflavones have been shown in some studies to reduce risk of breast and other cancers by inhibiting the formation of estrogen in fat, blocking the enzyme aromatase, inhibiting estrogen receptors, turning hormones into inactive forms, and through various antioxidant mechanisms. Blood levels of estrogen may be reduced by moderate intakes of soy foods such as soy milk, miso, and tofu.

Sugar Plays a Role

Modern diets, high in processed foods, deliver fibre-reduced foods that release a lot of sugars into the blood very fast. These foods are considered to have a high glycemic index if they charge up the blood sugar faster than 60 percent when compared to eating pure glucose. After a meal the glucose goes into the blood, and the pancreas responds by releasing insulin, a pump that moves sugars, fats, and proteins into cells where they can be used.

The liver responds by releasing insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) to make cells grow. IGF-1 and IGF-2 are major stimulators of growth for many cancers, and as cancers get more IGF receptors, they grow faster, metastasizing throughout the body. There is evidence that a high-glycemic meal can accelerate the growth of liver tumours by up to eight-fold for up to three hours. High-glycemic meals can include ordinary foods such as bananas and watermelon, soft breads, potatoes, parsnips, corn, beets, or cooked carrots. It is the total sugar balance which is vital, and cancer patients definitely need to carefully regulate their blood sugar. There is no excuse for the sugary "energy foods" promoted for cancer recovery in years past. The ideal low-glycemic sweets for cancer patients are blueberries, strawberries, grapes, and pears. (For tips on low-glycemic foods see "A perfect score: Use the glycemic index to convert carbohydrates into healthful eating," by Chris O' Brien, alive April 2004, p.126.)

Look on the Sunny Side

Research shows that the management of stress is critical to maintaining good immune function. Grief and other major life stressors can play a role in triggering cancer, and the stress of fighting cancer itself can be gruelling.

One of the most interesting phenomena in predicting cancer risk is the role of three factors: skipping breakfast, eating between meals, and irregular hours of sleep. These little behaviours seem to measurably increase cancer risk. While the specific mechanisms at work aren't yet known, it may be because these factors characterize a chaotic lifestyle. Chaos is stressful both physically and mentally.

Maintaining a positive outlook and tapping into social-support systems can improve quality of life and potentially assist survival. Prayer and meditation are currently being studied as adjunct or complementary cancer therapies. Hospice and palliative care units for terminally ill patients offer meditation, Touch for Health healing, chaplain services, and other spiritual solace. Finding meaning is the ultimate human creative endeavour. Through music, art, or journaling therapies, for example, a person can explore his or her reasons for wanting to live. Finding a way to approach life with zest and positive purpose is associated with some remarkable cancer recoveries.

Sloth, on the other hand, appears to be a deadly sin. In one observational study, the death rate from cancer for older men who walked more than two miles daily was half that of those who walked less than a mile each day. Exercise helps regulate blood sugar, moves the bowels, and improves immune functions such as the activity of cancer-eating natural killer cells.

Get Enough Sleep

At the end of your day, you go to sleep to rest and repair. One of the most important antioxidants and hormone- and cell-growth regulators is melatonin, made in the pineal gland in the brain. Between 8 pm and midnight, melatonin is produced in the pineal gland if the person is at rest in a dark place. Any light or disturbance can disrupt this critical defensive molecule. Early studies suggest that disturbed sleep, as experienced by shift workers, may increase risk of cancer, probably by throwing off the melatonin cycle. You may need an entire month of sleeping from 10 pm to 6 am in a completely blackened bedroom to restore a natural melatonin rhythm.

Avoiding Environmental Toxins

Considerable gains in health come from simply not doing some foolish things, such as using tobacco products. Thirty percent of all cancer risks are eliminated if you kick the tobacco habit. No other single behaviour is responsible for so much carnage. In Finland a successful program to curb smoking produced a reduction in lung cancer deaths proportional to the numbers who quit.

There are many substances in the home and work environments which are known to cause cancers if they accumulate to high levels. Quite a few of them are brought into our homes as cleaners and solvents. We use even more in cosmetics and body care products. A conscientious effort to use "green" products in our homes and on our bodies will take some strain off the detoxification mechanisms in the liver. The liver has to get rid of a lot of non-nutritive substances in the food and water, as well as in any drugs we take. If the liver gets bogged down in the early phase of detoxifying a carcinogen, it is caught with even more toxic oxidized carcinogens. Fortunately, herbs and foods such as turmeric and raspberries can rebalance detoxification, binding the oxidized chemicals to carriers which then take them out of the body. A supervised program of detoxification is recommended once or twice a year to minimize build-up of hazardous chemicals.

Less is More

The most dramatic thing one can do to live longer is to reduce caloric intake. A weight gain of over five kilograms in adulthood is enough to measurably increase risk of several of the leading causes of death such as heart disease, high blood pressure, diabetes, and cancer. Remember that fat, created from an excess intake of sugars and fats, can generate high levels of estrogens in the body. Obesity is almost as hard on the system as tobacco.

Early Warning Systems

The best diet, supplements, surroundings, and psychology cannot prevent all cancers. There are insidious threats, such as the radiation still circulating from Chernobyl and from DDT used in the 1950s and 1960s. The final step in a healthy lifestyle must be wise use of early screening tests to detect cancer while it can still be cured. Breast exams and prostate exams, PSA blood tests and PAP smears are examples of reliable methods that may save lives.

Supplements, while not proven to prolong life, can compensate for common deficiencies in the Canadian diet. Consider supplementing a varied, whole foods organic diet with:

  • multivitamins containing basic antioxidants and B-complex (50 mg daily for B1, B3, B5, B6, and B12; folate 1 mg; biotin 1 mg) and minerals including selenium (100 to 400 mcg), iodine (100 to 350 mcg), and chromium (100 to 400 mcg)
  • vitamin C (up to 3,000 mg)
  • grape seed extract antioxidants (100 to 300 mg)
  • calcium (1,000 to 1,500 mg) with magnesium (350 to 500 mg) and vitamin D3 (400 to 800 IU)
  • fish oil or plant-based omega-3 fats (1,000 to 3,000 mg)
  • flaxseed or psyllium fibre (1 to 2 Tbsp/15 to 30 mL)
  • probiotic bacteria (one to three capsules)
  • green drinks such as chlorella, spirulina, or barley grass (1 tsp to 1 Tbsp/5 mL to 15 mL)
  • indole-3-carbinol (200 to 400 mg).

Take a deep breath, sip some green tea or pure water, and enjoy life. It is easy to choose a natural lifestyle and healthy diet that can help your odds of preventing, fighting, and surviving cancer.



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Leah PayneLeah Payne