* This week’s study made media headlines worldwide and generated much interest on Twitter.
* It claimed that having examined data from 216,695 people, red meat intake (total, processed and unprocessed) increased the risk of developing Type 2 Diabetes (T2D).
* This makes no sense from the outset, as diabetes is a glucose handling issue and meat contains no glucose. It would be more obvious to suspect the buns, fries and fizzy drinks that hot dogs and burger are consumed with.
* I reviewed the paper and found 14 issues. There may be more:
Issue 1 – the inaccuracy of Food Frequency Questionnaires (upon which this study was based).
Issue 2 – the reported intakes were changed (the researchers ‘calibrated’ the reported intakes, which increased risk ratios.)
Issue 3 – the definition of red meat included sandwiches and lasagna.
Issue 4 – the serving sizes have changed since the original Food Frequency Questionnaires.
Issue 5 – the intakes used to compare people have become more extreme.
Issue 6 – the study claimed that women consume more red meat than men; that would be a first.
Issue 7 – total red meat was claimed to have a higher risk than both processed red meat and unprocessed red meat. Total red meat is the sum of the other two. It can’t be worse than both.
Issue 8 – the healthy person confounder. The red meat eater had a higher BMI and was more likely to smoke and less likely to exercise. We can’t adjust for a completely different person.
Issue 9 – the reported calorie intake was absurd.
Issue 10 – the characteristics table reported all food intake except the relevant ones – sugar and grains.
Issue 11 – the headline claims did not adjust for the higher BMI.
Issue 12 – even if there were no issues 1-11, the study could only suggest association not causation.
Issue 13 – the relative risk numbers grabbed the headlines; the absolute risk differences were a fraction of one per cent.
Issue 14 – the plausible mechanisms proposed applied far more sensibly to the bun, fries and fizzy drink (which were ignored) than to the burger.
The bottom line can be summed up by surgeon captain Peter Cleave. “For a modern disease to be related to an old fashioned food is one of the most ludicrous things I have ever heard in my life.”