From The August 2001 Issue of Functional Foods & Nutraceuticals
by Paul Clayton
How can the risk of cancer be reduced and what can enhanced nutrition do for the cancer sufferer? This article highlights some of the mechanisms involved in the battle against cancer.
As potential cancer victims most people tend to be more afraid of the treatment they may have to endure rather than the disease itself. The health philosophy that prevention is better than cure holds true for all diseases but none more so than cancer.
Cause And Effect
The four main causes of cancer are radiation, toxins, infections and, surprisingly, food itself, as certain foods can contain carcinogens. Although some recent techniques such as cancer 'immunisation' are promising, they are not available just yet. In the meantime, a series of safe, inexpensive, nutritional steps can be taken in the fight against cancer, as follows:
Antioxidants are known to neutralise the dangerous free radicals produced inside the body by radiation and by some toxins. These include:
- Vitamin A, C, E, D, K and some of the B group
- Co-enzyme Q 10
- Alpha-lipoic acid
- Carotenoids, e.g. lycopene
Another group of cancer protective substances found in food are the enzyme inducers. These are compounds, which stimulate the body into producing higher than normal amounts of 'detoxifying' enzymes. Some of these enzymes can neutralise free radicals and others can speed up the removal of carcinogens from the body. For example compounds like quercitin and sulphorophane, can be found in onions, broccoli and cabbage.
Substances which improve the immune system's ability to mount a defence against foreign organisms such as cancer cells are known as immuno-enhancers. Various herbs like echinacea have been shown to increase the number of natural killer cells, which can kill cancer cells. They also boost the production of interferon, a natural anti-cancer 'hormone'. Some ingredients in plant fibre, such as the pectic polysaccharides, have a similar effect, as do related polysaccharides found in certain mushrooms, fungi, the cell walls of some bacteria and the gritty particles in pear skin. Furthermore, lactobacilli and Bifidobacteria are linked to enhanced immune performance. Although Co-enzyme Q10 is not strictly speaking an immuno-enhancer, it is thought to be of benefit when used in conjunction with the above agents, as it increases the energy input into the immune system.
Plants And Protective Enzymes
Fruits and vegetables contain antioxidant vitamins and other compounds, which have the ability to shield the human organism. Dr. G. Williamson's team from the Food Research Station in Norwich, have evaluated hundreds of different foods in order to establish whether certain foods have the ability to boost levels of the antioxidant enzyme quinone reductase.
Their theory is that by eating these foods levels of quinone reductase will increase. Consequently, the bodily defences against free radicals will improve and offer protection against cancer. Various foods are also known to stimulate the formation of two other groups of detoxifying enzymes called Phase I and Phase II enzymes.
Phase I enzymes are oxidative enzymes, whereas Phase II enzymes have the ability to make dangerous compounds more soluble and are therefore more easily excreted from the body. Work is currently being carried out on Phase II enzymes, which have been found in high concentration in cabbage and onions families. A study by H.E. Poulsen et al. found that the amount of genetic damage by smokers was reduced when large amounts of Brussels sprouts were consumed. Other vegetables, which are good at inducing Phase II enzymes, include red pepper and garden peas. Interestingly, different kinds of cabbage show different effects. For example, Savoy rhapsody was more effective than other strains. Raw basil and rosemary are both very effective at stimulating the body to make its own antioxidant enzymes.
Many cancer specialists no longer talk about cancer killing, but cancer management or containment. This is based on the idea, that in order for cancer to grow or to metastasise from its site of origin it must produce Matrix-Metallo-Proteinases (MMPs). Over twenty different kinds of MMPs exist, which are mainly responsible for eating holes in the cellular matrix. Blocking the MMPs is therefore the key to cancer containment and different food extracts have already been found to act at different stages of metastasis.
Firstly, the rate of MMP production in cancer cells can be reduced by lectins derived from the elderberry plant, as reported by Van Damme et al. Furthermore, Rooprai HK et al. has also demonstrated that flavonoids in citrus fruits are able to block MMPs. Secondly the proteases (enzymes) responsible for activating the MMPs can be blocked by protease inhibitors such as the Bowman Birk compound (another lectin), which occurs in high levels in soya beans. Thirdly MMPs, which have been activated, can be blocked by various flavonoids. For example, some have the ability to bind the zinc atom at the heart of the MMP enzymes. Fourthly, those activated MMPs, which remain active, can be prevented from attacking the matrix with flavonoids, which bind to elements in the matrix and provide shielding from the enzyme attack.
How Effective Is The Nutraceutical Approach To Cancer?
The evidence is persuasive. For example, the proanthocyanidins (a group of flavonoids) cause 100 per cent inhibition of MMPs (Kuppusamy UR. et al) at levels which were achieved in the body by taking grapeseed extract supplement, or by drinking 1/2 to 3/4 litres of red wine per day. Other flavonoids, which are almost as effective as the proanthocyanidins at blocking MMPs, include luteolin, apigenin, kaempferol, silbi and olive oil.
Many carotenoids (found in carrots, apricots and squashes) are known to have the ability to inhibit cancer development at low, non-toxic doses. The inhibition is generally reversible, so that, when the carotenoids are withdrawn, the cancer begins to grow again. Lycopene (found in tomatoes), which belongs to the group of carotenoids is the most important micro-nutrient and among the most potent anti-cancer dietary factors. In clinical studies, lycopene has been linked to a significant degree of protection against cancers of the gastrointestinal tract (Garewal HS, Shandas GJI), breast (Bateiha AM et al), the cervix (Palan PR et al) and especially of the prostate (Giovanucci E et al).
The cancer management described in this article may be able to hold many cancers in check for years, perhaps indefinitely. It is very likely that some cancers managed in this way, starved of nutrition, unable to spread and forced to re-differentiate, will eventually die off. Other cancers however may persist or become resistant. If this happens cancer killing may be the only option and nutrients like fish oils (PUFA) or selenium have a role to play here too. There is some evidence that Omega 6 PUFAs in plant oils are anti-cancer agents (Falconer JS et al). Furthermore some animal experiments have shown that Omega 3 PUFAs in fish oil inhibit tumour growth.
Nutrition is the key in the fight against cancer, whether it is as a pre-emptive strike, or at a stage where the cancer needs to be contained or killed. Currently with solar radiation, smoking and pesticides, very few people perhaps 1 in 10,00 only die of old age. The vast majority die prematurely due to some disease. What is needed is a medicine for the 21st century and with all this evidence at hand it is just a matter of time that our diets should become adjusted and that food manufacturers will want to produce more functional food geared towards the fight against cancer.
Excerpted from Health Defence
By Dr Paul Clayton Ph.D.
Accelerated Learning Systems Ltd.
Aylesbury, Bucks, UK.
+44 (0) 1296 631177
Price: £ 12.99