Ad Hominem ad Nauseum
Argumentum ad hominem is a logical fallacy that has no place in science, but unfortunately is all too common in health, nutrition, and obesity policymaking. The most recent example comes from sensational UK media reports critical of an eminent nutrition scientist — Ian Macdonald — for advising both food companies that sell sugary products and the UK government on sugar-related health issues.
In one report, Simon Capewell, an advisor to the advocacy group Action on Sugar, commented on Macdonald’s perceived conflicts, saying, “It’s like putting Dracula in charge of a blood bank.” But the Chair of Action on Sugar, Professor Graham MacGregor, declined to comment on Macdonald. He said, “Action on Sugar also works with the food industry but we don’t stand any nonsense from them.”
The UK Department of Health defended Macdonald: “Professor Ian Macdonald has fully declared his conflicts of interest in accordance with the Code of Practice. He is a highly respected figure within the public health community and has made a valuable contribution to research into obesity and nutrition.
An ad hominem attack is typically utilized to compensate for weak evidence behind a proposition someone is trying to advance. It is an obnoxious distraction. The real need is for integrity in research, acknowledging all sources of bias, and addressing inevitable biases through scientific rigor, not ad hominem fallacies.
It’s hard to imagine a worse idea than discouraging public health and nutrition experts from offering their best advice to companies who make the food we eat. But ad hominem attacks on those who do so might have just that effect.
The Angry One, Oil painting by Ferdinand Hodler / WikiPaintings
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