Can a Low-Calorie Diet Slow Aging?

The Fountain of Youth may not be a myth after all. According to new research, it's in your brain, found in proteins called sirtuins.

A chemical found in wine, resveratrol, has been shown to stimulate sirtuins, which is why red wine is believed to help you live longer. Research has also linked increased sirtuin production to low-calorie diets.

The theory that fewer calories lead to a longer life dates as far back as the 18th century Japanese philosopher and scientist Kaibara Ekiken. He lived to be 84, which was twice the average life expectancy at the time he died.

An Extra 14 Years of Life

If a high-calorie diet can cause obesity, which can lead to diabetes, heart disease, and more, doesn’t it stand to reason that a low-calorie diet can reduce a person’s risk of dying prematurely?

Developmental biologist Dr. Shin-ichiro Imai says that links between a low-calorie diet and longevity have already been found in a variety of animal models.

In a new study published in the journal Cell Metabolism, Imai and others at the Washington University in St. Louis School of Medicine argue that a specific sirtuin, SIRT1, operates in the brain to significantly delay aging. It does this by enticing areas in the hippocampus to trigger changes in skeletal muscle.

"We found that only the mice that overexpressed SIRT1 in the brain (called BRASTO) had significant lifespan extension and delay in aging, just like normal mice reared under dietary restriction regimens," Imai said.

At 24 months old—the mouse equivalent of a 70-year-old human—the BRASTO mice appeared as active as five-month-old mice. For humans, this would mean women could live an extra 14 years and men an extra seven years.

Previous studies on mice showed that increased sirtuins could extend their lives by 15 percent.

Fewer Calories Doesn’t Mean a Long Life for Everyone

However, the longest-running study on calorie restriction in our closest evolutionary cousins showed that eating less doesn't necessarily mean living longer. Last year, the results of a 25-year National Institute on Aging study on rhesus monkeys showed that restricting the monkeys’ calorie intake didn’t make them age more slowly. It is possible, however, that this was because the male monkeys were so thin they equated to a 6-foot-tall, 130-pound human male. That equates to a 17.6 on the body mass index, which is considered underweight.

The results of the National Institute on Aging study shocked researchers, because a 2009 study at the University of Wisconsin found that caloric restriction slowed the aging process of the monkeys, including reducing the incidence of brain atrophy, cancer, cardiovascular disease, and diabetes.

That study had a major flaw, the New York Times noted: researchers discarded some monkey deaths because they were deemed unrelated to age, thus skewing the data in favor of overall longevity. 

Unfortunately, high levels of sirtuins have also been linked to an increase in anxiety and panic disorders, showing that yet again, if it's the Fountain of Youth you're seeking, you may need to keep looking.

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