Maybe there’s no need for a fountain of youth after all. New research suggests that cutting calories by 15% for two years can slow the metabolic process that leads to aging and protect against age-related diseases.
After just one year on a reduced-calorie diet, study participants saw their metabolic rates drop significantly. The lowered rate continued into the second year and led to an overall decrease in oxidative stress, a process that has been tied to diabetes, cancer, Alzheimer’s disease and other age-related conditions.
“Reducing calorie intake provides health benefits to all people regardless of their current health status,” said Leanne M. Redman, lead author of the study and an associate professor at Pennington Biomedical Research Center at Louisiana State University.
Animal studies have shown that restricting calories by 25% can extend life. The new CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) study was designed by Redman, her colleagues and the National Institute on Aging to answer a simple question: Would the same be true in humans?
During the first phase, teams of researchers ran small-scale pilot experiments to answer a variety of questions including, what kind of calorie restriction could study participants actually stick to? To this end, some of the pilot studies tested a diet-only calorie reduction, others tested exercise only, and still others tested half-diet, half-exercise.
Another question posed by the researchers: What level of calorie restrictions would have an impact on biomarkers of aging?
Aging biomarkers are simple biological measurements that differentiate longer-lived people — those who celebrate birthdays into their 90s and 100s — from people who live the average life expectancy, Redman said.
“We know that longer-lived individuals are able to sustain lower blood sugar levels and lower levels of insulin and have lower core body temperature levels in comparison to people who don’t live as long as them,” she said.
After the pilot studies, the National Institute on Aging committed to funding larger phase two CALERIE studies at three universities: Pennington in Baton Rouge, Washington University in St. Louis and Tufts University in Boston.