Eat Less, Live Longer
Photography by: Pornchai Mittongtare
Compelling human research
To pinpoint those gains, the National Institutes of Aging pumped $30 million into a two-part, multicenter study of calorie-restriction dieting aptly known as CALERIE (short for Comprehensive Assessment of the Long Term Effects of Reducing Intake of Energy). Results of the second phase won’t be available until 2012, but the first phase hints at what’s to come. After just six months of restricting calories by 25 percent, first-phase volunteers appeared to age more slowly than those subjects who ate normally. Specifically, study participants’ metabolism became more efficient and their insulin sensitivity rose, meaning their blood was able to handle the rise and fall of sugar with more sensitivity, vital for heading off diabetes. Other human trials hint at the diet’s ability to lower cholesterol, eliminate hypertension and even improve memory.
The slow-motion aging seen in the CALERIE study and others mirrors what researchers see in people like Walford who’ve made the calorie restriction diet a way of life. “I didn’t think calorie restriction worked in humans until I started working with people who’d been doing it for years,” says John Holloszy, M.D., CALERIE study’s lead investigator at the Washington University School of Medicine in St. Louis. “They are among the healthiest people I’ve ever known. Their heart function is similar to people 15 years younger, they have very low levels of inflammation and very few get cancer.”
Why it works
While scientists are still waiting for a collective “aha!” moment, there are many well-established theories about how calorie restriction slows aging. The most likely is its ability to stave off oxidative stress. Oxidative stress is the accumulated wear and tear on the body and is caused by free radicals, a natural byproduct of the body’s metabolism. (Think of free radicals like the carbon dioxide produced when you burn gas driving your car.)
By restricting the amount of calories entering the body, cellular engines are forced to be more efficient (hybrid vs. SUV), and the entire body hums like a well-oiled machine. More efficient cellular engines mean less metabolic waste and fewer free radicals spewed into the body. Since free radicals play a role in nearly all age-related diseases, especially cancer, heart disease and diabetes, the result is healthier aging.
How to get started
At its core, says Walford, caloriere-striction dieting is simply about becoming more calorie conscious. “It’s about discerning between calories that nourish the body and those that deplete the body,” she says.
To start, put as many low-calorie, nutrient-dense foods within reach as possible. Fill up the fruit bowl with wash-and-go produce, such as apples, pears and plums; put dried apricots in the cookie jar; stash a baggie of raisins and raw almonds in the glove box.
Cook to maximize nutrients. Mix and match raw and lightly cooked (steamed or stir-fried) vegetables in your diet. Most important, start slowly. Don’t fixate on decreasing your calorie intake by 25 percent. Start with 5 percent. If that goes well, bump it up to 10 percent. Even mild degrees of calorie restriction are beneficial to long-term health, says Holloszy. “This diet doesn’t have to be all or nothing; even a 10- percent reduction in calories would benefit most of us,” he says. Adopting a few basics from the calorie-restriction handbook can lead to better health, if not a longer life. (More information can be found at walford .com, or visit the Calorie Restriction Society website, crsociety.com, for recipes and tips on getting started.) “Personally, I don’t do it in hopes that I live longer,” says Walford. “I do it so that I can live better now.” But, she adds, “If I do live longer, it’ll be a nice bonus.”