Dietary supplements

A health diet should concentrates on substantial whole foods and not supplements which attempt to concentrate separate anti-cancer constituents of food into convenient tablets or potions. Although the concept of a quick fix oral supplement is attractive, as we all know, life is unfortunately not that simple, especially when considering the integrate genetic and constantly changing biochemical cancer pathways. Cancer is a devious creature capable of changing its spots to avoid attack from the body’s internal immunological defences and external drug and lifestyle factors. It has been hiding and evolving in mankind’s genes for millions of years and although science has discovered a lot, it’s the tip of the iceberg in terms of the whole picture. It is at best naive or indeed arrogant to assume that pulling out one or two aspects of the dietary jigsaw and putting it into a pill is going to help in the long term. In the same way as blocking the flow of a stream, will inevitably lead to the water finding new tributaries, cancer will form new pathways to avoid, environment or chemical attack. If diet or other lifestyle factors are to have any impact on established cancers, especially in the long term, it needs to influence as many stages in the cancer pathway and as many biological and immunological processes as possible. Eating the whole food in as much diversity as possible is likely to avoid deficiencies in these vital defence pathways.

There may be other concerns about supplements compared to concentrating on whole healthy foods.  Some of the large trials have shown that upsetting the dietary balance of nature and taking too much of a good thing, may be harmful both in terms of cancer and other important illnesses such a heart disease and strokes. Although there is still much to learn from ongoing studies, I and many enthusiasts have considerable reservations that supplements, in some situation, could do more harm than good.

 Summary of concerns with oral dietary supplements:- 

• They offer an attractive quick fix to health
• May distract people from the real issues of lifestyle.
• Some trials have shown increase risk of cancer and heart disease.
• Other long term risks remain uncertain until more data available.
• Very few trials have actually shown a benefit for cancer.
• Individuals with an underlying deficiency have shown a benefit
• Nutritional deficiencies could be corrected with a balanced diet
• They can add expense to the cost of living

Is there a place for dietary supplements? The concerns about do not necessarily insinuate there is no place at all for supplements. Instead it emphasises that caution should be taken, especially if long term consumption may take place of a “one tablet fits all” where chemicals if not excreted fast enough could accumulate in the body. There is likely to be a place for good quality supplements after cancer but further evidence from ongoing clinical trials is required. It is also likely that more individualised supplements are necessary along with close monitoring of their ongoing effects. The existing trial data already suggest that correcting a pre-existing deficit such as zinc or selenium has anti cancer benefits but overcorrecting a normal value is counterproductive. Ideally future trial design should include bespoke blood, urine, saliva or toe nail analysis to identify those individuals with sub-clinical deficiencies in trace elements and vitamins, which may lead to an increase risk or progression of cancer especially under circumstances of high carcinogen exposure. The level and type of dietary supplements for each individual are also likely to differ considerably depending on patient’s dietary history and genetic susceptibility.

 A start to developing an individualised supplementation system would be to simply measure blood levels of vitamins, minerals and essential fatty acid levels although these have not always reliably been found to reflect the true status of individual requirements. Sensitivity can be helped by dietary questionnaires and in-depth face to face consultations but this may not always be practical. The future, however, may well lay in more complex tests which match the blood levels of essential nutrients with specific biochemical pathways which in turn reflect the molecular makeup of each individual. This may even include an analysis of their genetic signature (the pattern of genes in their DNA). This is a long way from picking up a bottle of multivitamin from the shelf of the local drug store. The cost and inconvenience of these tests are currently prohibitive, but if genetic testing advances at the rate it is doing currently this may not be too much of a fantasy. In the mean time there are some bespoke tests which are currently accessible but are not freely available outside specialist, and expensive nutrition clinics or trial units. These include; measurements of serum metabolites that accumulate in vitamin deficiencies instead of vitamins themselves providing a longer term view rather than a snap shot at that time; or chemical blood markers that measure the baseline oxidative state (BOS) which is thought to reflect the body’s ability to fight off the free radicals correlating with the function of the primary oxidative defence enzymes, such as catalase, glutathione S-tranferase glutathione and superoxide dimutase.