Eating less over a long period of time can help you live a longer life — and also protect you from developing Alzheimer’s, Parkinson’s, cancer and diabetes, a new study suggests.
Scientists from several organizations studied 53 non-obese adults for more than two years. The participating scientists came from Louisiana State University’s Pennington Biomedical Research Center in Baton Rouge, Louisiana; the Translational Research Institute for Metabolism and Diabetes at Florida Hospital and Sanford-Burnham Medical Research Institute in Orlando, Florida; and Georgia State University’s School of Public Health in Atlanta.
Participants cut their calories by 15 percent over the study period. Though participants predictably lost some weight (an average of nearly 20 pounds), the payoff was much more profound than a smaller dress or pants size.
“Restricting calories can slow your basal metabolism, and if byproducts of metabolism accelerate aging processes, calorie restriction sustained over several years may help to decrease risk for chronic disease and prolong life,” said lead author Leanne M. Redman, associate professor of Clinical Sciences at Pennington Biomedical Research, in Science Daily’s coverage.
The payoff for cutting back on calorie consumption drove significant health and lifespan improvements. Those improvements came from two sources: decreased metabolism and decreased systemic oxidative stress.
Metabolism has to do with how efficiently our bodies expend energy. A fast metabolism, though prized for its association with weight loss, is also associated with a shorter lifespan.
“We know from mammalian studies that the smaller the mammal, the faster its metabolism and the shorter its longevity,” said Leanne M. Redman, the study’s lead author, in Science Daily.
Consider hummingbirds. Tiny hummingbirds must eat almost constantly. They have extraordinarily fast metabolisms. At scale, if they were as big as human beings, they’d eat the equivalent of 155,000 calories a day, Audubon reports. However, the tiny creatures only live for three to five years. So that exceptionally fast metabolism comes at a price.
Scientists theorize that oxidative damage explains why we age as we do. In addition, oxidative stress — which is reduced when one limits calories — is associated with neurological conditions like Alzheimer’s and Parkinson’s. It is also implicated in cancer, diabetes, and other diseases, Science Daily reported.
The idea is that the DNA, lipids, and proteins in our bodies sustain damage from the byproducts of “oxidative phosphorylation in mitochondria,” per the study authors’ report in the journal Cell Metabolism.
Oxidative phosphorylation is the process by which cells “breathe” and produce energy. Mitochondria are the cell organelles responsible for producing that energy (they help get rid of and recycle waste, too), and they use oxygen to do so. Mitochondria also play an important role in ensuring that unwanted cells — those making up tumors, for example — die.
That is why cancer drugs often target mitochondria .
The bottom line is that by reducing calories, folks can give aging a substantial one-two punch to the gut. A decreased metabolism (in this study, a decrease of about 80-120 kcals a day) coupled with decreased systemic oxidative stress can mean living a longer, healthier, more youthful life.
The results published in Cell Metabolism last week were from the second phase of the researchers’ CALERIE (Comprehensive Assessment of the Long-Term Effects of Reducing Intake of Energy) study. Their work was funded by the National Institutes of Health.
Michele Blood is a Flemington, New Jersey-based freelance writer and a regular contributor to LifeZette.