Weight loss aside, eating less may yield hefty benefits




Home \| Elder Rights \| Health \| Pension Watch \| Rural Aging \| Armed Conflict \| Aging Watch at the UN

	SEARCH	SUBSCRIBE
			Mission \| Contact Us \| Internships \| Donate Now!

back

Aging Well: Weight loss aside, eating less may yield hefty benefits

By Kelly Greene, The Wall Street Journal
October 21, 2003

Can cutting calories lengthen your life?

It's been shown to work in worms, insects and mice, and it's looking likely in monkeys. Now, scientists are moving on to the final frontier: people.

At research centers in Louisiana , Massachusetts and Missouri , pilot experiments have started this year in which human guinea pigs are cutting back on how much they eat by as much as 30%. The participants in the studies are all normal weight to slightly overweight, not obese. The researchers recruiting them stress that weight loss is not the overall goal. Any weight loss is simply a side effect as scientists study whether so-called calorie-restriction programs can help people stave off chronic diseases that increase with aging -- such as cancer, diabetes and heart disease -- or even help them live longer.

"We're not in weight reduction, we're in caloric restriction," says Charles Hollingsworth, the former chief of the clinical-trials branch at the National Institute on Aging , or NIA, which is sponsoring the studies. "Early on in caloric restriction, you will get weight reduction. Then some people put weight back on, but kind of in a different way."

Already, some volunteers are seeing changes in their health. At Tufts University 's Jean Mayer USDA Human Nutrition Research Center in Boston , Monique Hawkins recently realized that she didn't experience a trace of the summer sinus problems that usually plague her -- though there were days when the prepackaged food she was provided left her craving something fresh instead.

Observations like those are exactly what the NIA, based in Bethesda , Md. , is seeking from these early trials, each of which includes 40 to 50 people and will last about a year. The goal is to figure out which experiments work best, as each research center tinkers with a different combination of diet and exercise to keep people on the low-calorie regimen needed to test their overall health. The next step for the $20 million research initiative is a two-year study involving hundreds of people, which will try to answer the questions at the heart of the investigation: Does calorie restriction really add years to human lives? Will exercising to work off calories provide the same benefit? Or is the key to avoid the calories in the first place?

Anecdotal Evidence

No one is sure why cutting calories seems to be a path to the fountain of youth. One common theory among scientists is that digesting smaller portions cuts down on toxic byproducts called free radicals, which are considered a possible culprit in Alzheimer's disease and other illnesses that disproportionately strike the elderly.

Researchers first noticed in the 1930s that mice fed significantly smaller portions seemed to live longer, healthier lives than those allowed to chow down with abandon. Tests on myriad creatures followed, working their way up to rhesus monkeys in the 1980s.

In humans, there's one naturally occurring example of the apparent benefits of calorie restriction. On Okinawa , a Japanese island, people typically eat 20% fewer calories than average in Japan itself -- and Okinawa has a much higher rate of centenarians than the country's overall population.

About 15 years ago in the U.S. , a few individuals started using calorie-restricted diets with the idea of getting all the necessary nutrients with as little as 60% of the food they used to eat. Today, at least several hundred people are followers of such calorie-restricted optimal nutrition. Some adopted the routine after being diagnosed with high cholesterol or diabetes. Unfortunately, there are no uniform measurements of their baseline health, so their current physical condition is of little value to scientists.

Battery of Tests

That's where the new studies come in. It will take decades, of course, to tell whether dietary changes actually extend people's lives. (With most lab animals, the suspense is over in about three years, though monkeys are a notable exception.) So scientists managing the experiments are using biomarkers -- the red flags of aging , such as heart rate, stiffening of the arteries and inflammation -- to track the diets' effects.

At all three centers, participants go through a series of blood tests and measurements of heart rate, aerobic capacity, cholesterol, fat, insulin, metabolism, depression and other indicators. None of the results are in yet, but the researchers are hopeful that they will see a decrease in some indicators in the first year of research.

The investigators are trying to figure out whether it makes more sense to test younger people or older people as well. At Tufts and Pennington Biomedical Research Center in Baton Rouge , La. , the subjects range in age from 20 to 50. The third site, Washington University School of Medicine in St. Louis , is focusing on people ages 50 to 60.

The tests, ideally, also will provide answers to questions that loom in the larger two-year study, says Dr. Hollingsworth of NIA. One of the biggest: How do you control what goes into participants' mouths 24 hours a day?

Clearly, it's tough to forgo almost every snack -- whether it's brownies, potato chips or beer -- in hopes of tacking on a few more years of living. To date, though, volunteers who have stuck with the experiments say they have been surprised at the volume of food they have been allowed to eat, which has helped them stay faithful, for the most part.

"Sure, every now and then I crave certain foods," says Scott Westbrook, a 41-year-old health-insurance consultant taking part in the Pennington study, who weighs 169 pounds and is 5 feet 9 inches tall. "But they've given me enough to eat -- lots of fruits and vegetables, and three to four ounces of meat at a time -- that I'm not hungry."

He was attracted to the study by the many tests that were included. "I'm going to get more information about myself than you would ever get through a primary-care doctor," he says. He'd let his own health routine get "out of whack," and he's started feeling better while eating three meals consistently each day, along with regularly jogging on a treadmill.

"My body is converting what it takes in immediately to energy, and I'm not lying down feeling miserable, like I overate," say Mr. Westbrook. In just three months, his body is using oxygen much more efficiently.

'As Easy as Possible'

At Tufts, volunteers are eating 30% fewer calories than what they ate before entering the study. But they are on two different diets. One is a modification of the federal government's food pyramid, and is higher in carbohydrates; the other is a diet with more protein and fat, says Susan Roberts, the lead investigator there. For the first six months, participants pick up their food from the center and attend group meetings once a week. For the second six months, they fix their own food.

Ms. Hawkins previously ate a high-protein diet because she lifts weights regularly and is interested in building strength and muscle tone. But she was put on the higher-carbohydrate diet in the study and has been surprised to see that she has maintained her muscle tone, even while losing 15 pounds. "My perception of protein needs was apparently much, much greater than what my body needs," she says.

Dr. Roberts says her main goal is to work out "what to feed people to make [calorie restriction] as easy as possible. ... We are testing different dietary options to see what minimizes hunger and allows you to feel adequate dietary satisfaction."

In the St. Louis program, participants prepare most of their food on their own and are split into groups that eat 20% less than they did previously or exercise enough to burn off 20% of those calories. Most of the exercisers are doing well, says lead investigator John Holloszy, but the challenge is "keeping their food intake the same. Normally when you increase your exercise, you increase your food intake as well."

Sharla Bilchik, a 57-year-old St. Louis resident in the Washington University study, says she was attracted to the experiment specifically because "it's not a weight-reduction program, it's caloric restriction to gain health benefits."

Almost four years ago, she was diagnosed with sarcoidosis, an inflammatory disease that can affect the lungs. "It was debilitating for me," she says. After she went into remission, she decided to enroll in the study because she wants "to take care of myself in the best possible way I can, and know what's going on in a physical sense within my body."

Measuring everything she eats is "arduous," says Ms. Bilchik, "but I'm motivated because of my own health and what I see around me," working in an ophthalmologist's office with many older patients. "I don't want to be like that. I want to be active till the end."