Monday, May 08, 2006

Eat Less, Live Longer… Seriously… Well, Maybe

Calorie restrictive (CR) diets are back in the news. This time around, a University of Florida (UF) study (which I found by way of ScienceDaily) finds even small cutbacks in calories can stretch lifespans. How small? Eight percent, though it doesn't say how much time that buys you. Also, this study was performed on rats. As far as I know, the affects of a calorie restrictive diet have yet to be observed on human lifespans.

However, a study by the Washington University School of Medicine,
reported in the summer of 2004 by the Genome News Network (GNN) , shows that people on a diet restricted to between 1,000 and 2,000 calories "scored vastly better on all major risk factors for heart disease," compared to those on a normal diet. The people on a calorie restricted diet also had low levels of CRP, a protein that cause inflammation. According to the report, CRP "is strongly believed to be a factor in diseases."

The University of Florida study also brought up inflammation. Said Christiaan Leeuwenburgh, an associate professor of aging and geriatric research at the UF College of Medicine, “in a calorie-restricted environment, you reduce the inflammatory response and prevent cell death." In other words, you slow the aging process which, according to Leeuwenburgh, is also spurred by "unstable molecules known as free radicals" and, of course, cellular oxidation.

The free-radical theory of aging is nothing new.
According to Wikipedia, "The free-radical theory of aging is that organisms age because cells accumulate free radical damage with the passage of time." Free radicals are created when the body converts oxygen to energy. And there's less of that going on when you eat less. Whether or not that's actually prolonging life is debatable. Back in 2002, MIT reported that one of its biologists, Leonard Guarente, found evidence that free radicals do not cause aging.

But don't stock up on potato chips and ice cream yet. Guarente still found that calorie restriction prolonged life-- not by reducing free radicals, but by increasing respiration. Sound bizarre? Well, increased respiration, according to Guarente, causes increased production of a "silenced information regulator," or SIR2, gene. This SIR2 is what slows aging. Yes, that's utterly confusing.
I suggest you read the MIT report, which I read about 10 times-- and its still a little hazy to me.

Alas, the question still remains. How much longer can you live by starving yourself? Well, according to data from studies on rodents, Dean Pomerleau, a man on a calorie restricted diet, estimates that each calorie spared adds 30 seconds to his life. That equals three hours per piece of pizza. For more on Dean's philosophy,
visit the aformentioned Genome News Network report here.

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I started pound360 to channel my obsession with vitamins, running and the five senses. Eventually, I got bored focusing on all that stuff, so I came back from a one month hiatus in May of 2007 (one year after launching Pound360) and broadened my mumblings here to include all science.