Will the centuries-old search for the fountain of youth end in Baton Rouge? The answer may be as close as a familiar building on Perkins Road.
In 2002, Pennington Biomedical Research Center (PBRC), Washington University in St. Louis and Tufts University in Boston shared a $30 million National Institute on Aging grant to establish a study called the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy, or CALERIE. Pennington’s portion of the funding—$12.4 million—was the largest grant ever received in Louisiana from the National Institutes of Health.
Predicated on studies that show a 25% calorie reduction decreases biological signs of aging and increases longevity in everything from yeast to spiders and mice to monkeys, the ongoing CALERIE study examines whether the same result can be replicated in humans.
Co-investigator Leanne M. Redman, a native Australian, came to the Capital City to join Swiss researcher Eric Ravussin in the quest. “Nobody knows why we age,” Redman explains. “[But] there are two ways in which we age: The first is called primary aging, and that is the irreparable damage that happens to our DNA, [which is] just a function of getting older. For example, wrinkles and gray hair [are] the biological effects of aging that we really don’t know how to stop.
“Then, the secondary causes of aging are things that are not necessarily biologically determined. They’re influenced by our lifestyle—smoking, being overweight, these kinds of things. These are call age-associated diseases, things that are on the rise as we get older: diabetes, high blood pressure, heart disease, stroke, cancers.”
CALERIE I began with a small six-month pilot program that ultimately demonstrated changes in calorie reduction were safe for study participants, could be instituted without cloistering the participants in a research facility and could be measured in the metabolic rate.
After one year, calorie-reduction volunteers had lowered their fasting glucose levels, total cholesterol, core body temperature, body weight, DNA damage and visceral fat and had increased cell function.
Since 2005, CALERIE II has focused on analyzing body chemistry before, during and after calorie reduction in relatively healthy, average-weight adults with the use of a special metabolic chamber.
The study requires overnight stays at the facility and other lengthy testing, so PBRC compensates volunteers for their time with a $5,000 stipend.
After initial diagnostic testing, scientists calculate the number of calories individuals need to maintain their current weight for two years. That number is decreased by a quarter to determine a calorie target. Then, participants receive personalized counseling with a dietitian and eat a month’s worth of meals at the Pennington center to understand, acclimate to and incorporate changes in their diets.
After this 30-day orientation, one third of participants become part of the control group, resume their normal lifestyle and return to the center for testing at designated intervals. The remaining two thirds record their food intake on a computerized calorie counter and return for monthly support group meetings and intermittent testing.
“In the calorie restriction group, we typically get three results,” says Redman. “They can find it fairly easy to reach their calorie target every day, find it hard and begin to put their weight back on, or restrict too much and their body weight tends to come down even further than what we expect.”
Pennington dietitians are so successful at keeping individuals’ progress on track that only two of 55 participants have left the study. At the end of the two years, researchers will compare the groups’ body fat, cholesterol, weight and other markers to discover whether individuals on calorie restriction are healthier than those who did not modify their calorie intake.
No matter the scientific outcome, Redman maintains the testing alone provides invaluable information to health-conscious participants. “It’s a unique opportunity to have all these state-of-the-art metabolic tests that aren’t available to people outside of a research setting—to get your health information and to know within two years where you are healthwise,” she says. “That’s a baseline for you for the rest of your life.”
Colleen Clark and Tasha Thomas agree. A little more than a year ago, both were accepted into the study.
Clark was searching for job possibilities rather than a lifestyle change when she logged into PBRC’s website. When she realized she fit the demographic requirements for the CALERIE study, she quickly became intrigued.
“It’s been very interesting, because they do things you would never think about,” Clark says. “At Weight Watchers, it’s on the point system, and [the program’s] the same for everybody. Here, they consider bone density, age, and look at everything down to the most minute detail. You wear a hood to get your resting metabolism. You are sealed in a chamber with a CO2 monitor, have blood work and other tests to determine how many calories your body needs per day. There’s so much you can learn about yourself.”
The Lakeland, Fla., native was randomly selected for the calorie reduction group. After several months of measuring and recording everything she eats, Clark remains enthusiastic.
“I’ve pretty much eaten the way I always have but with reduced portion size. I’m not hungry, and I don’t feel deprived. I’m still tailgating,” she says with a smile.
“[Losing weight] wasn’t my top priority. I was just interested in being part of the research project. When I look at the other significant research [Pennington’s] done, it’s encouraging.”
Clark expected to lose a little weight; however, with a few changes, she dropped 30 pounds. Her husband—who is not a participant—lost 17 pounds, which was enough to motivate their college-age son to carefully consider his food choices.
For several years, Tasha Thomas’ good health prevented her from enrolling in PBRC’s diabetes and obesity protocols. When a group of her friends qualified for CALERIE, she applied.
After the initial month of testing and education, Thomas was assigned to the control group and not required to make any lifestyle changes.
Still, says the New Iberia native, “I took the nutrition guides for the necessary portions, and they’ve helped me to make healthier decisions. I check nutrition guides now when we go out to eat. I didn’t realize foods were loaded with so many calories because I never checked.”
She adds, “I cook more than I used to, and [my fiancé] started grilling. What I learned from the study influences the way we eat. It’s life-changing because it makes you more aware of the foods you’re eating.”
While Clark’s and Thomas’ experiences have positively influenced their social sphere of spouses and friends, greater acceptance of calorie reduction to improve life expectancy may be a while in coming.
In fact, CALERIE presented researchers with a rare opportunity. “It’s very unlikely the NIH will ever fund a study like this again,” Redman says. “Phase III would be to do a large study of people in the community with educational materials and followup phone calls. Participants would do [calorie restriction] on their own, outside of the research setting. To do that in real life is virtually impossible. So, this study’s going to be a gold mine for a lot of years to come.”
Redman expects information culled from CALERIE, combined with other scientists’ research on centenarians, to provide greater insight into the factors that influence longevity.
For example, the Japanese island of Okinawa has four to five times as many people over age 100 as other industrialized countries. Researchers have also discovered that Okinawans maintain a healthy diet and eat 20% fewer calories than most Japanese.
“What is amazing is [people who live independently over age 100] have the same causes of death as people that are 70 years of age. They might get diabetes, Alzheimer’s and heart disease, but not until their late 90s. The aging process is delayed. What is special about these people? We have to put it all together, the puzzle, to see if calorie restriction is beneficial,” Redman says.
CALERIE’s value to science should be long-lived as well. Blood work, data and samples from the current participants will be available for testing future discoveries on bio-marker aging.
“Early on, we had a meeting with the first 20 participants,” Redman recalls, “and [Dr. Ravussin] told them they were going to be famous.” Already, Ravussin and Redman have become sought-after experts from bastions of academia to the televised weight-loss competition The Biggest Loser. During the show’s eighth season, Ravussin collaborated with celebrity doc Robert Huizenga to conduct energy expenditure studies on the TV show’s contestants. Ravussin is also slated to appear on the season finale.
Yet, for all its scientific validity, the study constantly comes under fire. “People ask: ‘Why do we want to find an anti-aging gene, when we’re not designed for that?’” Redman reports.
“But it’s quality of life,” she explains. “Even if we didn’t alter your life expectancy, wouldn’t you want to live independently and free of disease until right at the end—like the 100-year-olds—without having to take medicine?”
