The Society for Neuroscience annual conference is, as usual, a big crowd-puller. Looking down the huge poster halls you get the impression you can see the curvature of the Earth. Well you could if the place wasn’t totally heaving. I started by heading straight for a poster that I hoped was going to make me feel terribly self-satisfied.
It was about calorific restriction (CR): the theory that says animals live longer if they restrict the number of calories they eat. It works in rodents and tests in primates are underway. It also has its human fans, and they annoy the hell out of me. They eat markedly less calories, say 80% of normal, and smugly talk about out-living their peers.
Now this is clearly a crazy idea, since there is no point living longer is it means less cheese, hamburgers, beer and the other things that making living worth it in the first place. So I was delighted to see a poster that revealed that mice on CR diets suffer more from stress. You eat less pies and, in the short term at least, all you get is more moody spells; surely this was the nail in the coffin for CR?
Unfortunately it seemed my hopes were a little too high. The data is very preliminary and only suggests that the CR mice are becoming more susceptible to stress. More interesting are the implications for weight-loss diets. The initial findings show that once off a CR diet, the mice go into a spectacular rebound. Four months later they are still eating more than controls. Tracy Bale, the University of Pennsylvania researcher behind the study, said she couldn’t believe how fat the CR mice were. Which, she says, might explain why the majority of diets don’t help people loose weight — perhaps humans get the same cravings when they finish diets, and simply put the weight straight back on.
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