Two interesting papers. One shows popular anti-oxidant ‘supplements’, beta carotene, and vitamins A and D, far from making you live longer, have the opposite effect. Another shows that garlic does not lower cholesterol. And some publicity for Dan Hurley’s book, Natural Causes. An update looks at the activities of the supplements industry spokesperson. Dr Ann Walker, who seems sometimes to forget to declare her interests.
First let’s reiterate the myth of antioxidants
Nutribollocks: the antioxidant myth
“Nutritional supplements” are one of the most profitable scams (see, for example, Healthwatch, Quackwatch, and Holfordwatch).
There is a nice article by Lisa Melton on The Antioxidant Myth: a medical fairy tale in tne New Scientist (and see here), [download as pdf] . Here are some quotations.
|Cranberry capsules. Green tea extract. Effervescent vitamin C. Pomegranate concentrate. Beta carotene pills. Selenium. Grape seed extract. High-dose vitamin E. Pine bark extract. Bee spit.You name it, if it’s an antioxidant, we’ll swallow it. According to some estimates around half of US adults take antioxidant pills daily in the belief that they promote good health and stave off disease.
. . .
In 1992 researchers at the US National Cancer Institute set about testing beta carotene. The trial was set to run for 6 years, but two-thirds of the way through the researchers pulled the plug after discovering, to their surprise and horror, that those taking supplements were doing worse than the controls. They had developed 28 per cent more cases of lung cancer, and their overall death rate was 17 per cent higher.
It’s a similar story with the world’s most popular antioxidant. Vitamin E shot to fame in the early 1990s, after two large studies involving more than 127,000 people in total found that those with a diet high in vitamin E were significantly less likely to suffer cardiovascular disease. Use of vitamin E supplements soared. In 1990, almost nobody took vitamin E; by the end of the decade an estimated 23 million US citizens were knocking back daily doses.
“Treatment with beta carotene, vitamin A, and vitamin E may increase mortality”
That is the conclusion of a recent paper in the Journal of the American Medical Association, “Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention” Systematic Review and Meta-analysis”, [Get the full text].
This isn’t original research, but a meta analysis that attempts to collate existing data taking into account the reliability of each source. The aim was to analyze the effects of antioxidant supplements (beta carotene, vitamins A and E, vitamin C [ascorbic acid], and selenium) on deaths (from any cause) in adults. The analysis seems to have been done well, and the results are startling. They aren’t just a waste of money, but some of them are actually bad for you. In 47 low-bias trials with 180 938 participants, beta carotene increased death rates by 7 per cent, vitamin A by 16 per cent, and vitamin E by 4 per cent (when taken separately). Vitamin C gave contradictory results and selenium showed no detectable effect.
This work got an excellent write-up in The Times, by their health correspondent, Nigel Hawkes. This was followed by a predictably silly defence of nutribollocks by the Times’ Dr Thomas Stuttaford (known in Private Eye as Dr Utterfraud). Luckily, this was neutralised by a second piece on the same page by Nigel Hawkes, “Phooey. Sensible balanced diet is the best investment”:
“ In nutrition, a plausible idea and a little bit of evidence are all that is needed to create a market. And such is the megaphone of marketing and the influence of countless “healthy eating” articles that these ideas, even the half-baked ones, can lodge very firmly in the national psyche.”
It’s a nice coincidence that this study came out while I was reading Dan Hurley’s book, Natural Causes (see below). This book sets out dramatically the harm, sometimes serious harm, that untested “supplements” have done to some individuals. But for me the most interesting part is the revelation of the political lobbying by this $20 billion supplement industry, with the aim (largely successful) of undermining the FDA and escaping from any effective regulation of its absurd, but exceedingly profitable, claims. The supplements industry puts the Prince of Wales in the shade when it comes to subverting common sense and good science.
The Health Supplements Information Service (HSIS)
Needless to say, the supplements industry has already organised vilification of this excellent bit of work.
According to their web site,
“HSIS is funded by The Boots Company PLC, Bayer PLC, Perrigo, Seven Seas Ltd and Wyeth Consumer Healthcare. The campaign is co-ordinated by PAGB (Proprietary Association of Great Britain)”.
So it’s no surprise that their spokesperson. Dr Ann Walker, immediately tried to discredit the study, saying “The results of these mixed-sample metaanalyses are worthless” (The Times).
This same Ann Walker recently wrote and editorial in the British Journal of General Practice (January 2007). The editorial concludes “Although still considered to be controversial by some, taking a daily multinutrient supplement would bridge the gap between intake and requirements and ensure that nutrient target intakes are met.” But in this editorial her affiliation is given as Senior Lecturer in Human Nutrition, University of Reading. No mention at all of her role as spokesperson for the Supplements industry. Tut tut.
Patrick Holford too
Needless to say, supplement salesman Patrick Holford has weighed into the vilification. His objections have been dealt with nicely on the cutely named web site stopholfordtalkingrubbish.blogspot.com. Find the answers here.
Holford is the man who, in the BMJ said “Competing interests: none declared”, when promoting his supplements.
No interests? Holford himself has said
“any product, be it a publication, seminar, food or supplement, that is authored/invented by me has my name on it and earns me a royalty/payment. That is how I live and fund my research.”
So what about the galaxy of supplements being sold at “Health products for Life”? They say “we only supply supplements, foods and drinks that are recommended by nutrition expert, Patrick Holford.” And at the bottom of the page it says “©Copyright 2007 Holford and Associates. All Rights Reserved”. Companies House lists the sole shareholder in ‘Health Products for Life’ as P.J. Holford.
Garlic is no good either
Another interesting recent paper has appeared in Archives of Internal Medicine
Garlic is widely promoted as a cholesterol-lowering agent, but the evidence so far has been lousy. In this trial, 192 adults with low-density lipoprotein cholesterol (LDL-C) concentrations of 130 to 190 mg/dL (3.36-4.91 mmol/L) were randomly assigned to one of the following four treatment arms: raw garlic, powdered garlic supplement, aged garlic extract supplement, or placebo.
“Conclusions None of the forms of garlic used in this study, including raw garlic, when given at an approximate dose of a 4-g clove per day, 6 d/wk for 6 months, had statistically or clinically significant effects on LDL-C or other plasma lipid concentrations in adults with moderate hypercholesterolemia.”
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