The Sugar Wars: Does The Sweet Stuff Kill?

Science can’t prove it and Big Sugar denies it, but Gary Taubes is convinced that sugar kills.

- Daniel Engber

“I hope that when you have read this book I shall have convinced you that sugar is really dangerous,” wrote John Yudkin in his foghorn-sounding treatise on nutrition from 1972, Pure, White and Deadly. Sugar’s rapid rise to prominence in the Western diet, starting in the mid-19th century, had coincided with a sudden outbreak of heart disease,diabetes, and obesity. Yudkin, one of the United Kingdom’s most prominent nutritionists at the time, believed that one had caused the other.

Then, as now, there was no decisive test of his idea—no perfect way to make the case that sugar kills. It’s practically impossible to run randomized, controlled experiments on human diets over many years, so the brief against sugar, like the case against any other single foodstuff, must be drawn from less reliable forms of testimony: long-term correlations, animal experiments, evolutionary claims, and expert judgments. In Pure, White and Deadly, Yudkin offered all of these as “circumstantial evidence rather than absolute proof” of his assertion. But so many suspicious facts had already accumulated by 1972, he claimed, that it would be foolish to ignore them. Even based on circumstantial evidence, readers should be convinced “beyond reasonable doubt” of sugar’s crime against humanity.

The story of what happened next may be familiar, not just in its particulars but in the broader pattern that it represents. In the 1970s, Yudkin’s enemies, chief among them the influential American nutritionist Ancel Keys, ridiculed and buried his idea. On the basis of research sponsored by the sugar industry, Keys and others created and enshrined a different dietary bogeyman as the source of heart disease and other chronic ills: not sugar, but saturated fat. Yudkin’s book went out of print. Low-fat diets went mainstream. Sugar got a pass.