Each week I receive many phone calls and emails to my office from individuals wishing to reduce their risk of cancer.  It is something most of us think about from time to time because unfortunately cancer has become so common in modern society.  I am also seeing it developing in younger and younger patients more frequently.  When I first began my medical training it was quite unusual to see cancer in those under the age of 40.

I believe there is a great deal we can all do to strengthen our immune system and look after our DNA (genetic material), and in that way reduce our risk of developing cancer, plus improve the chance of survival if you have already been diagnosed with cancer.

If you have a family history of bowel cancer, it’s more likely that you are intolerant to gluten. This can be tested with a blood test to check your genotype for HLA DQ and DR gene patterns. If you test positive, you will reduce your risk of bowel cancer by avoiding gluten containing foods. Gluten is found in wheat, rye, barley, spelt and oats and many processed foods.

If you are low in selenium, you will be at greater risk of many types of cancer, including lymphoma, bowel cancer, skin cancer and cancers of the mucous membranes. You will also be more vulnerable to getting cancers caused by some viruses, such as the Human Papilloma Virus and the hepatitis viruses.

It is difficult to know if you are low in selenium as blood tests only show the tip of the iceberg; in other words your blood selenium levels may be normal or even a little high, if you have recently been taking selenium supplements, but the deeper parts of your cells may still be deficient in selenium. Selenium is stored in the nucleus and mitochondria of your cells where it exerts a protective effect against genetic damage. It takes several months to “selenize” your cells, meaning to put the selenium into the deeper parts of the cells where it must be stored. Accurate selenium status can be ascertained by tissue biopsy or toe nail clippings, but these tests are expensive.

Generally speaking, selenium is very safe, as it is an essential nutrient for all humans and animals. It is not easy to become toxic from selenium – you would need to eat huge amounts of Brazil nuts everyday or take mega doses of selenium supplements. The toxic dose is generally considered to be 900mcg of selenium daily over a period of time – there is no reason to take these huge amounts! Generally speaking selenium overdose comes from industrial pollution. Indeed it’s far more dangerous to be deficient in selenium than it is to take too much!

The Food and Nutrition Board (FNB) sets the tolerable upper level for selenium at 400mcg daily in adults – this upper limit includes selenium obtained from food, which averages around 100mcg/day.  I usually recommend a minimum of 100mcg daily, but in people with cancer risk or a weak immune system, I recommend 200mcg daily.

For more information see http://www.seleniumresearch.com/

Vitamin D
If you are low in vitamin D you will be at greater risk of many types of cancer including skin, lung, and bowel cancer. Do you know your blood level of vitamin D? The vast majority of people do not know this life saving information.

Vitamin D can be measured in two different units of measurement and in the USA the units used are ng/mL. In Australia and Canada the units of measurement are nmol/L.

The normal ranges of vitamin D for blood tests reported by different laboratories and countries vary significantly and you will be surprised by the large range between lower normal and upper normal – see table below

Lower Limit Vitamin D Upper Limit Vitamin D
75 nmol/L 200 nmol/L
30 ng/mL 80 ng/mL

You don't want to be average here; you want to have levels of vitamin D that optimize your immune system to fight infection and inflammation. The optimal levels of vitamin D are higher than the average levels.

I recommend you take enough supplements of vitamin D3 and/or get enough sunshine to keep your serum vitamin D levels around 150 to 200 nmol/L or 70 to 80ng/mL. Vitamin D3 supplements are not expensive.

St Mary’s thistle
I’m sure you’re aware that the herb St Mary’s thistle has remarkable liver protective properties, but did you know it may also reduce the risk of cancer?  Research has shown that this herb can help to repair DNA and reduce angiogenesis.  Angiogenesis means the formation of new blood vessels and it is how tumors can spread throughout the body.  [Anticancer potential of silymarin: from bench to bed side.:Anticancer Res. 2006 Nov-Dec;26(6B):4457-98.Agarwal R, Agarwal C, Ichikawa H, Singh RP, Aggarwal BB. Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA].

Antioxidants in vegetables
The average person doesn’t consume anywhere near enough vegetables, particularly raw vegetables.  It is not enough to eat a small serving of vegetables with dinner.  Ideally you would consume a large salad with lunch and dinner each day.  During winter it is fine to consume most of your vegetables cooked, whereas in summer it’s best to have them raw.  I am a strong advocate of raw vegetable juice because it’s an excellent way to boost your intake of nutrients and antioxidants in an easy to digest form.  Vegetable juice is excellent for strengthening the immune system, boosting energy levels and improving the quality of your hair and skin.  You will find many inspiring juice recipes in my book Raw Juices Can Save Your Life.

The above statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease.