You will no doubt have seen the usual media headlines from a study suggesting that we could die early if we take too many supplements. I have to admit to feeling very weary whenever I see this type of story. My first thought is, of course, too much of anything is ‘too much’ and anything, even too many carrots, can have a harmful effect if you abuse it.
However, using my new found skills of research methods and how to critically analyse research to see if it is robust enough to take notice of, guess what, it isn’t. When asked yesterday, I noted that, from a quick look, I didn’t see how you could extrapolate the researchers’ conclusion for statistical data which leaves out an awful lot:
…in older women, several commonly used dietary vitamin and mineral supplements may be associated with increased total mortality risk.
For a start, how woolly is that? What’s all this ‘may’ business?
I looked at how the study was conducted and saw that it was a load of self-reported questionnaires, not even consistently done and relying on memory of what supplements some had taken with no details of how much, what types, how long for, what other meds they were having, what health conditions they had etc etc. Then, they computed statistics. Not what you call robust research then. In fact, some critiques are saying that, if you look at the actual study more closely, the conclusions showed that those taking supplements were actually much more likely to follow health lifestyles too – and it is beyond doubt that stopping smoking and eating your veggies is protective not harmful.
But, don’t just take my word for it – here is what the Alliance for Natural Health International has said after analysing the data thoroughly, and you can read their full report from the link:
Our view is that the self-reporting questionnaires, and lack of any supporting data on nutrient status of the study’s subjects, means that the majority of the trends emerging from the adjusted data on which the study’s conclusions were based are likely to be anomalous. This is especially the case given that the most powerful trend, the apparent benefit of calcium supplements, contradicts other findings from much more robust studies.
A very clear example that should ring alarm bells for any scientist, practitioner or doctor reading the study is that in the case of vitamins, such as vitamin D, where there is overwhelming evidence of benefit, no positive findings emerged. But no, the authors could quietly ignore the huge tranche of empirical and published evidence that abounds, and publish their findings in the knowledge that they had satisfied their null hypothesis.
I think the Vitamin D point is a really valid one. If the study suggests no positive benefit, despite thousands of contradictory studies on bone health alone, then there has to be something wrong with the conclusions. In my view: another example of a weak, statistically-massaged study which flies in the face of thousands of stronger studies saying the exact opposite. But guess what the media were given and reported…again. (Sigh).
Supplements are not a substitute for a rubbish diet and they are powerful, life-transforming and mostly protective elements providing the short-fall in many people’s nutrient status. We should respect them as such.