Saturday, 1 September 2012

On Calorie Restriction, Monkeys, Magic and Medicine

Science Writer David Stipp RSS Feed highlighted new research on Calorie Restriction in Monkeys published this week in Nature (ref 4).

1) On Calorie Restriction, Monkeys, Magic and Medicine - Compares to Wisconsin 2009 study. David Stipp comment 'CR hasn’t extended lifespan in all species, nor has it worked in certain strains of rodents. In the latest study on the topic, it failed to extend lifespan in a long-term study in rhesus monkeys at the National Institute on Aging (NIA)....the study suggested that CR improved late-life health in the monkeys, but the effect was modest and gender-specific.... dietary factors potentially gave a boost to the NIA controls’ health as they aged, which might have contributed to the fact that they were about as healthy and long-lived as the monkeys on CR in the study '

2) - Nature staff writer comment 'Calorie restriction falters in the long run - Genetics and healthy diets matter more for longevity.'

3) - Steve Austad comment

4) - Nature Journal primary research.

5) NY Daily News

6) - Luigi Fontana comments that possibly no effect of CR seen because monkeys were all on high protein diets. In humans, those hormones decrease only when protein intake is dramatically reduced. It's not enough to cut calories alone. "It's possible that we don't see some of the beneficial effects of longevity in these monkeys because they were on a high-protein diet," Fontana said. "The old idea is that a calorie is a calorie. When you restrict it, you have a beneficial effect. Our data and other data suggests this isn't the case. The quality of the diet matters," Fontana continued.

7) Luigi Fontana believes both studies should have paid more attention to dietary composition. "Fifteen per cent of the monkey diet came from protein – that's too much," he says. "Our work suggests lowering protein, rather than calories, may be the key to increasing longevity – so reducing protein intake could have led to better results." De Campo agrees that dietary composition might play a role in lengthening life, but claims the benefits of calorie restriction are still strong. "Although we don't have the same lifespan findings as the Wisconsin group, what's really important is that we did show similar improvements in health."

8) Intermittent Fasting website. Talk about lower IGF-1 levels with low protein diets.

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