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Is the GI a key to unlocking a hidden addiction?
Doing something about the obesity epidemic is at the top of most public health agendas. Talk about budget blow out! The financial cost to the whole community of burgeoning waistlines is scary. New Zealand scientists from the University of Auckland explore the idea in Medical Hypotheses that addiction could be an important factor causing the obesity epidemic. They compare and contrast the evidence about nicotine addiction to food and GI and suggest that if high GI foods like corn flakes or white bread are the villain of the piece, ‘low GI equivalents may be the saviour’. The point of the study is really the public health implications of the theory. As the researchers point out: ‘Just as tax increases and control of advertising have proved effective in reducing the prevalence of smoking, similar strategies may help reduce the obesity epidemic.’
Dr Simon Thornley
Lead researcher Dr Simon Thornley, from Auckland Regional Public Health Service, said foods with a high GI caused blood glucose levels to spike, and this rush stimulates the same areas of the brain associated with addiction to nicotine and other drugs. He reports evidence showing that people who binged on high GI carb foods experienced loss of control, a compulsion to keep taking higher amounts to get the same ‘buzz’, and suffered withdrawal if they went ‘cold turkey’.
‘It's a novel idea that draws on strong evidence that glucose consumption influences levels of the feel-good chemical serotonin in the brain, says Sydney University’s Prof Jennie Brand Miller. ‘Although all foods take about 30 minutes to peak and the overall shape of the post-meal glycemia curve is similar for high, medium and low GI foods, high-GI foods peak and fall at substantially greater levels. Our recent study that explored the association between a food’s GI and the shape of the curve clearly suggests that to control high blood glucose after meals, carb quality (or its GI) and carb quantity both count (see the abstract). So the general message is say “low GI” with carb-rich foods as well as watching portion size.’