Cancer prevention

What protects against cancer?

There is good reason to believe that the immune system is the most important agent both in the prevention and the treatment of cancer, ie to protect from cancer before it may develop and to conquer cancer after it has started developing.
In fact, several thousands cancer cells are routinely destroyed by a healthy immune system inside your body every day.

In the human body, many abnormal cells, genetically different and with the potential to become cancer cells, are formed every day. Usually the immune system destroys them before they start reproducing. However, when, for some reason, the body's natural defences are weakened or else they cannot identify and destroy the abnormal cells, the latter quickly reproduce, invade the healthy tissues and destroy the body.

So, the task is to strenthen the immune system, so that it can deal with cancer in a way that it cannot still be matched by drug treatment or radiotherapy.
And a major part of this is nutrition.

It is now widely recognised that poor diet causes as many cancers as smoking, and the World Health Organisation (WHO) has identified that one third of all new cancer cases are preventable through improved diet. The Western-style diet, which the WHO stresses as a key factor in its prediction of a 50% increase in cancers worldwide, is one that leaves people simultaneously overfed and undernourished, as it relies on processed foods high in sugar, salt and fat.

Yes, it seems a bit counter-intuitive sometimes.
We find it much easier to believe that cancer is caused by something we put into our mouths and our bodies, rather than something that we omit to put into them.
The idea of a poison (pesticides or whatever the current fad is) is much easier to grasp because it has a biological foundation: our ancestors, men in pre-historic times and even pre-hominids, were perhaps already afraid of poisons.
And yet, scientific knowledge does not necessarily adhere to our intuition and may even be far removed from common sense: just think of quantum mechanics and relativity theory as good examples of counter-intuitive science.

Vitamins & minerals

Deficiences of almost all vitamins have been linked with cancer, notably some B vitamins, vitamin C and vitamin E. Research has repeatedly found that low levels of vitamin A and its precursor, beta-carotene, are linked with cancer.
Beta-carotene's advantage over ordinary vitamin A is that the body will only convert it into A when necessary, thus avoiding overdose. Laboratory tests found that beta-carotene destroys human cancer cells. It is found in fruits and vegetables that are green, yellow or orange: for example spinach, watercress, broccoli, carrots, apricots, tomatoes all have plenty of it.
Strangely enough, American research suggests that beta-carotene taken as a supplement is better absorbed by the body than when it is eaten as food.

The Oxford Book of Health Foods says:
"Prevention of cancer. Vitamin C is an antioxidant, and may enhance the immune system as well as blocking the formation of potential carcinogens from compounds in the food or water. Studies on the potential for prevention of cancer are inconclusive for lung, breast, colon, and rectum, but there is stronger evidence of a protective effect for stomach cancer".

Soil lacking the trace mineral selenium, a non-metallic element, correlates with high cancer rates. Lack of selenium and lack of vitamin E are also related.
Populations with high levels of selenium both in the soil of the areas where they live and in their blood have much lower rates of cancer as well as heart disease.
Selenium is present in seaweeds, especially in kelp, and has practically disappeared from Western soil. It helps to prolong the lifespan of human cells.
Selenium may even act to stop early cancer cells in their development (and can even cause regression of cancer already developed). A study in the Journal of the American Medical Association (JAMA), the leading journal of American physicians, reported a 37 percent decrease in the incidence of cancer among patients who were assigned a selenium supplement. A 50 percent decrease in cancer mortality in those people on the selenium supplement was also observed.
Vitamin E and selenium act together (they are synergic) in cancer prevention. The U.S. National Cancer Institute (NCI) funded a 12-year study of 32,000 men without prostate cancer in 430 Canadian cities. After 6 years there was a 40% reduction in mortality rate in the group that received vitamin E. Another study showed that after 10 years of treating the patients with selenium, there was a 70% drop of prostate cancer occurrence among those of the patients who received the treatment versus placebo. Vitamin E and selenium are found in some varieties of nuts and seeds.

Zinc, involved in the immune function, is also needed for the effective action of vitamins C and A. Too much salt, together with a shortage of potassium, may encourage cancer, and a risk of colon cancer may be higher with a lack of calcium or vitamin D.

Fibre

We generally eat too little fibre and too much fat. Fibre helps wastes to pass quickly through the body so that any toxins are not held in prolonged contact with the bowel lining, and it probably dilutes any carcinogens too.

In the USA, the regulatory body Food & Drugs Administration, allows claims to be made for the health benefits of consuming wholegrains in relation to both cancer prevention and heart disease. For example:

"Low-fat diets rich in fiber-containing grain products, fruits, and vegetables may reduce the risk of some types of cancer, a disease associated with many factors."

Soya

The Oxford Book of Health Foods says:
"Medical claims for soya are based on human clinical studies, experiments, and epidemiological evidence. Soya contains isoflavones (flavonoids), such as genistein, daidzein, and glycetein, known as phytoestrogens, which are similiar to human body oestrogens. These isoflavones, if consumed by women, reduce the level of blood oestrogen, one of the risk factors in breast cancer. Also, consumption of soya and its products is 10 times greater in Asian cultures than in Western countries. Breast and prostate cancer is considerably greater in Western countries than in the East. Although not direct evidence, these comparisons do provide some support for the value of soya as regards some types of cancer."

Less fats & calories

There is a link between both breast and colon cancer and high fat diets: this may explain why vegetarians, who avoid meat fat (the worst possible fat in diet), have lower rates of breast cancer.

Animal life has a curious bargain with the fat tissues stored in the body: through them our evolutionary history fitted us for survival during hardships, but made us at greater risk of death during the fat times.

Among individual foods that help protect against cancer is certainly garlic.
The authoritative The Oxford Book of Health Foods says: "A considerable number of scientific investigations, together with epidemiological evidence, have supported the medical value of garlic and its products:

• a) it is effective against some bacteria (e.g. Staphylococcus, Salmonella) and some fungi (e.g. Trichophyton, Candida albicans), and may have antiviral activity
• b) there is some evidence (from animal studies) that garlic can suppress cancer initiation and development
• c) it reduces blood sugar, triglycerides (fats), and high blood pressure
• d) it reduces blood cholesterol and improves the high-density lipoprotein to low-density lipoprotein ratio
• e) it has an antithrombotic (blood clotting) effect and an antiplatelet aggregation effect
• f) it can act as a vermifuge".

Eating to prevent cancer, therefore, means lots of fresh fruits and vegetables, raw plant foods, with all their vitamins and minerals intact; unrefined grains (again, nutritionally whole); with some protein (nuts, low-fat cheese, yoghurt, pulses); and very little added fat.

Some foods should be avoided, either in preventing cancer or in treating it. Gastric cancer is higher in people eating smoked food. In experimental tests, alcohol, cola drinks nad coffee were linked with bladder cancer. Food with fungus growing on it is also a risk.

Dr. Peter Greenwald, who was Director of the Division of Cancer Prevention at the National Cancer Institute, said: "There is now general scientific consensus that about 80% of cancers are linked to people's lifestyles. The role of diet in tumor prevention is particularly important. Among the useful substances are vitamin A, beta-carotene, vitamin C, vitamin E, vitamin B 6, vitamin B 12, folic acid and selenium".
The advice of the major cancer prevention authorities is: include more A, C and E vitamins, beta-carotene and selenium in your diet.

Over consumption of energy, that is the intake of too many calories, is also an important factor.
Eating too much food is one of the main risk factors for cancer. This can be shown in two ways: by the additional risks of malignancies caused by obesity, and by the protective effect of eating less food.

  Health and nutrition