The Irish Association of Nutritional Therapy have written a response to the Cochrane review of antioxidant pills. It’s not very impressive. Holford Watch have posted on it here: IANT and have also attempted to leave a comment (or comments) on the IANT piece. Unfortunately, the IANT appears to be blocking these comments and I haven’t been able to comment either. The following comment was stuck in moderation:
I’m afraid that not everything you have written in this response is true. For example, this: “The final exclusion involves the trials with selenium with no reason as to why. Selenium trials generally show a positive result on the disease in question when supplemented.” is simply untrue – as can be seen if you follow this link: http://holfordwatch.info/2008/04/26/irish-association-of-nutritional-therapy-giving-the-facts-about-the-cochrane-review-of-antioxidant-supplements/
When this comment failed to appear, I fired off a very brief email pointing out just one or two of the mistakes in the IANT piece:
Unfortunately, this piece: http://www.iant.ie/2008/04/18/response-to-the-recent-media-coverage-regarding-antioxidants/ contains several errors. I know that, as nutritional therapists, you will feel compelled to give the public the facts of this case and I am sure that you will amend any errors in your response to Cochrane. I look forward to reading the revised article.
“Many of the studies are with dosages that far exceed what is in most vitamin products.” – this has been covered by Dr Ben Goldacre in his Bad Science column in the Guardian. (1)
“The authors have excluded over 400 trials many of which have a positive outcome and have no deaths so if these were included the findings would be different.” – the study was on mortality. How exactly would those studies that do not report mortality be useful in studying mortality?
“There are no adverse risks with taking vitamin and mineral supplements that are available at the current levels.” – the levels of vitamins and minerals available at many ‘health food’ stores do have associated risks. (See again Ben Goldacre’s comments on available supplements)
“Research in the UK shows that many people are deficient in various nutrients. (4) It also shows that large parts of the population come nowhere near consuming 5 portions of fruit and vegetables especially in the younger populations. There is ample research to show that at least a third of all cancer is linked to diet.” Yes, cancer is linked to diet (i.e., the food we eat – not the vitamin pills we take). However – the evidence in respect of diet and health is for fruit and vegetables, not isolated nutrients sold in pill form.