Don't you just love it when the media jumps on a piece of medical research and reduces it to its lowest common denominator? 'Hooray for huge thighs', 'The thigh’s the limit', 'Thunder thighs protect your heart', 'Thin thighs health risk', 'Large thighs may halt heart risk', 'Bigger thighs are better for health': these were just some of the headlines accompanying coverage of a Danish study showing people with thighs measuring 60cm, give or take a centimetre or two, appear less at risk of heart disease and early death.
Now I knew even before checking that there’s no way my thighs measure 60cm ― or indeed ever have. So I thought I’d better read on, past the headlines and into the story source, a British Medical Journal article. And I was amazed to discover that research led by Professor Berit Heitmann of Copenhagen University Hospital did at first glance pretty much bear out what the headline writers were saying. In a nutshell, 1,463 men and 1,380 women ― all Danish adults aged 35-65 ― took part in the study, and were examined first in 1987-88 for height, weight, thigh, hip and waist circumference, BMI and so on. They were followed up for 10 years for incidence of heart disease and 12.5 years for total number of deaths, during which time 257 men and 155 women died; 263 men and 140 women experienced cardiovascular disease; and 103 men and 34 women suffered from heart disease. Those who survived were found to have higher thigh circumferences. Specifically, a thigh measurement of 60cm ― irrespective of age or gender ― was shown to afford the most protection, and Professor Heitmann and his colleagues are recommending GPs to include this as a new indicator of heart disease risk.
But wait a minute. While smoking was taken into account, as were alcohol consumption and education, diet does not appear to have been, which is odd. Exercise was meanwhile graded in four groups, ranging from sedentary to 'elite', although that was merged with the 'sports' group due to insufficient numbers. The categories do not appear to be very closely-defined, which is strange since you might think that pinpointing exercise levels would be a factor in this research. Indeed, the researchers themselves concede that 'for exercise, the possibility remains of residual confounding' ― scientific jargon for saying something may not have been controlled in the experiment and has created a false positive or negative. I then delved about a bit more and discovered that the researchers also took no account of the composition of the thighs being measured: 'The fact that associations were independent of percentage body fat as well as abdominal obesity suggests that the risk with smaller thighs might be associated with too little muscle mass in the region. It is a limitation that we did not measure tissue composition of the thighs to study this question.'Maybe, then, it’s not as simple as it sounds? Maybe it’s not just a question of tape measures; maybe it matters what inside there and how it was created. Perhaps the fact that my thighs, for example, comprise at least as much muscle as fat may prove more reliable as an indicator of my heart disease risk than the fact that they don’t measure 60cm. And is this study to be applied universally? Is it remotely relevant to rural populations in, say, South-east Asia or parts of South America who are exceedingly unlikely to ever get anywhere near the magic 60cm figure but rarely if ever succumb to heart disease? Even within Europe, does the magic number work where people are generally smaller and more lightly-built than in Scandinavia?
I am always wary of scientists who draw sweeping conclusions from their research, and I’m relieved to see that the BMJ’s editorial on this study is refreshingly cautious. Alas, though, the headlines are now well and truly out there, along with the very simplistic message they herald.