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Fat Tuesday: Sugar, obesity and the big C

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American



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By Cesarachp, via Wikimedia Commons

If you thought heart disease and diabetes were the main problems associated with obesity and overweight, think again. The latest news is that being obese or overweight is a major factor in cancer risk and severity. Science writer Sarah C. P. Williams does a nice analysis of the available evidence in the current issue of the Proceedings of the National Academy of Sciences. Even worse, once you’ve been fat, losing the weight may not reduce your future chances of having cancer. Experiments in mice indicate a lasting effect of being overweight on cancer risk, even after slimming down. The relationship between how long, and how long ago, you were overweight and your cancer risks remains unclear.

Gary Taubes, author of “Good Calories, Bad Calories” and “Why We Get Fat” tracks the problem to sugar, and explains that many human cancers rely on insulin, and a related hormone known as insulin-like growth factor, to grow and multiply. He convincingly argues that sugar intake, which causes chronically elevated insulin levels and insulin resistance, is the cause of many cancers. Taubes says he’s scared of sugar. Maybe we should all be.

Susana Martinez-Conde is a professor of ophthalmology, neurology, and physiology and pharmacology at SUNY Downstate Health Sciences University in Brooklyn, N.Y. She is author of the Prisma Prize–winning Sleights of Mind, along with Stephen Macknik and Sandra Blakeslee, and of Champions of Illusion, along with Stephen Macknik.

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