This week a major review of scientific research into whether certain antioxidant supplements improve health and extend life caused another debate on the usefullness and safety of nutritional supplements to erupt.
Scientists at Copenhagen University, Denmark, who are part of the respected Cochrane Collaboration looked at 67 studies on beta-carotene, vitamin A, vitamin C, vitamin E, and selenium
. The Cochrane Collaboration reviews are where many health professionals go for a definitive answer on whether a treatment is effective since they have strict guidelines on the studies they include, using only double-blind, placebo-controlled trials. For example the 67 studies used in this review were selected from a total of 817.
The review looked at the effects of antioxidants as it is suggested they may help to prevent damage to the body from 'oxidative stress' which has been implicated in a large number of diseases from heart disease to asthma and chronic fatigue syndrome.
The review included a total of 233,000 people who were either ill or taking supplements for disease prevention.
After excluding various other factors the researchers concluded that not only were the supplements no help but that vitamin A supplements increased risk of death by 16%, beta-carotene 7% and vitamin E by 4%. They said that vitamin C didn't appear to have an effect either way and that more research would be needed, as well as for selenium.
Now, it wasn't so much the study conclusions that shocked me the most the other day but the media coverage of them. Everything has to be reported in a sensationalist fashion it seems so what we got was the media essentially reporting that vitamin supplements will kill you so you better stop taking them!
This is just one study, albeit a review of numerous other studies, which only looked at a handful of supplements. It is well established by the way that beta-carotene, vitamin A and vitamin E are toxic when taken in large amounts since they are fat-soluble and therefore accumulate in the body rather than being easily excreted through the urine as water-soluble vitamins such as C and the B group would be.
Commenting on the study and media coverage well known nutritionist Patrick Holford said "Antioxidants are not meant to be magic bullets and should not be expected to undo a lifetime of unhealthy habits."
He went on: "But when used properly, in combination with eating a healthy diet full of fruit and vegetables, getting plenty of exercise and not smoking, antioxidant supplements can play an important role in maintaining and promoting overall health."
Holford also pointed out that the review only looked at studies which examined the effect they had on reducing mortality, rather than other advantages.
These are very good points. Since heart disease and cancer are the biggest killers the review included large numbers of people who were already suffering from these diseases. I don't think anybody would expect that a few antioxidant nutrients would be able to prevent the deaths of those with established heart disease and cancer. If these conditions are well established it is likely that the body would be unable to utilise these nutrients in a beneficial way.
In the case of vitamin C and selenium the way the results were reported is likely to leave the public thinking that these nutrients have "no effect either way" in ANY circumstance! This is clearly not the case. There are various studies which have established that antioxidant supplements are beneficial in specific conditions. These studies tend to look at how these supplements improve symptoms and quality of life rather than simply mortality rates.
Another problem is that the study only looked at a handful of nutrients but the reporting in the media made it sound like nutritional supplements in general are of no benefit. If we take the example of heart disease we can see that this could not be further from the truth. Elevated levels of a chemical known as homocysteine are known to be an independent risk factor for heart disease. A large group of researchers known as the Homocysteine Lowering Trialists Collaboration found that folic acid supplements reduce homocysteine by 25% and vitamin B12 supplements by a further 7%. Other major studies have shown that this equates to at least an 11% reduced risk of heart disease. It is also well established that supplements of vitamin B3 and omega-3 fatty acids can have very beneficial effects on cholesterol and reduce heart disease as a result.
So, it's very worrying to me that the media has this habit of simplifying what is a complex subject by simply focusing on the conclusions of a single study with a narrow focus. The public may now feel they shouldn't be taking supplements which may actually be doing them a lot of good.
In a TV news report on this study a dietician was calling for all nutritional supplements to be regulated in the same way as drugs. In some ways I can see where she was coming from. On the one hand the industry is unregulated and consumers are free to take as many pills as they like with little warning of possible toxicity or dangerous interactions with each other or with other medicines. The fact is however that each year there are very few cases of severe illness or death that are recorded as being attributable to nutritional supplements. On the other hand, pharmaceutical drugs are known to be the direct cause of thousands of deaths per year (example study). So should the same rules as apply for pharmaceuticals be applied to nutritional supplements? In my opinion they are clearly not comparable in terms of risk so the pharmaceutical regulation model is simply not applicable to nutritional supplements.
And what about the millions of us around the world suffering from chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome and a host of other conditions for which the medical profession including primary care doctors, specialists, and dieticians generally offer no worthwhile help whatsoever?
I am in no doubt that if I hadn't had the freedom to purchase and try a range of nutritional supplements for myself I would not be here today, I would have given up years ago unable to take the feelings of hopelessness and despair. As it is, based on doing my own research, scouring scientific papers and writings of a select group of doctors, I have found many nutritional supplements that have helped me a great deal and most importantly have given me a sense of empowerment that I have the ability to improve my own health.
What are your experiences and feelings about nutritional supplements? Have they helped you? Will you continue taking them after the conclusions of this study? Do you think they should be more strictly regulated?
Let us know what you think...