September 28, 2007
Harvard researchers find longevity, restricted diet link
From The Harvard Gazette:
Researchers believe they’ve found the cellular link between extremely restricted diets and dramatically lengthened lifespan and hope to use the knowledge to develop new treatments for age-related diseases. The research, conducted by scientists at Harvard Medical School, Cornell University Medical School, and the National Institutes of Health, illuminates for the first time the cellular processes triggered by extremely low-calorie diets. Scientists have known for about 70 years that extremely restricted diets — where caloric intake is 30 percent to 40 percent below normal — can extend lifespan by as much as a third. In addition, those years are healthier and relatively free of common age-related debilities such as cancer, heart problems, and type 2 diabetes. The longer, healthier lives have been seen in a host of animals maintained on a very low-calorie diet, including mice, rats, and monkeys. What scientists haven’t been able to figure out, until now, is why eating a lot less makes one live a lot longer.
The answer, it turns out, lies in tiny bodies inside each cell that act as cellular battery packs. As one ages, cells lose these battery packs — called mitochondria — and slow down. Extremely restricted diets, it turns out, revs them back up again. The research, published in the Sept. 21 issue of the journal Cell, shows that calorie restriction sparks a chain reaction within cells that creates two enzymes called SIRT3 and SIRT4. The enzymes cross into mitochondria, making them grow stronger and increase energy output.
More here.
Posted by Azra Raza at 04:20 AM | Permalink
Comments
I started cutting down last year. It seems to make me feel better to eat less.
Posted by: beajerry | Sep 28, 2007 5:16:13 AM
The extra third of life I would gain would probably be non-productive as I would be too tired and hungry to do any thing. So I dont plan to give up eating any time soon.
Posted by: Tasnim | Sep 28, 2007 7:44:51 AM
Having recently recovered from an eating disorder that claimed two years of my life, I'm inclined to agree with Tasnim. The physiological changes that occur as a result of restricting caloric intake - most notably, the dramatic differences in neurotransmitters in the brain - do sometimes lead to feelings of satisfaction and fulfillment (see beajerry's comment). The risks, however, far outweigh the benefits.
These chemical changes fundamentally alter our abilities to relate to other people, to perform physical activities, and even to engage in normal intellectual processes. While the researchers may have made a case for "living longer," they have failed to consider what truly constitutes "living." To live involves activities far more complex than simply engaging in biological processes, and severe calorie restriction often seems to preclude precisely those activities.
Posted by: Emily | Sep 28, 2007 8:59:31 AM
Fortunately, the point of this research seems to be for the rest of us to reap the benefits of restricted calorie-diets without actually, y'know, eating any less:
“What we’re working toward is a drug that gives the benefit of exercise and diet without having to exercise and diet,” Sinclair said.
Posted by: Jesse M. | Sep 29, 2007 3:50:35 PM
Jesse M., that's a drug I could get behind, but I'd actually prefer to wait my turn until they've developed the drug that gives the benefit of an excellent diet and proper rest from needful labor to people can't include either in their lifestyles.
Posted by: Elatia Harris | Sep 29, 2007 3:57:05 PM
"..a drug that gives the benefit of exercise and diet without having to exercise and diet..'
That goes against the rule that you can't have your cake and eat it (or, in this case maybe, not eat it?) I'm skeptical about the probability of only one physiological mechanism being involved, as proposed here. There are so many subsystems that have to work harder when you eat more, including insulin production, enzyme generation, the absobtion of nutrients via the gut, the kidneys, and so on. It is very difficult to research a process that has multiple causal factors, as ageing is widely believed to have, so scientists try to make their own lives easier by concentrating on just one factor and claiming that it is the only one.
My view is doubtless colored by my opinion that a real super-longevity pill would be a great disaster, with many negative social and economic consequences and very little increase in the "sum" of human happiness.
The Good Things in life are either 'unhealthy, immoral or make you fat'
Posted by: aguy109 | Sep 30, 2007 7:29:32 AM
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