A sustained lowering of food intake over time—while avoiding malnutrition—results in an increase of telomere length in adult mice, according to researchers at the Spanish National Cancer Research Centre (CNIO).This has a protective effect on the DNA and genetic material, and these beneficial effects on the youth of the chromosomes translate to a lower incidence of cancer and other age-related illnesses.
To carry out the study, researchers used young mice—just three months old—and reduced their caloric intake by 40% before observing them until the end of their life cycle.
“We see that mice that undergo caloric restriction show a lower telomere shortening rate than those fed with a normal diet,” says María Blasco, Ph.D., director of CNIO and head of the telomeres and telomerase group. “These mice therefore have longer telomeres as adults, as well as lower rates of chromosome anomalies,” she adds.
To study the effects of this phenomenon on the health of the mammals, researchers observed the incidence of age-related illnesses like cancer. The mice that had been fed a lower calorie intake showed a reduction in the incidence of cancer. Furthermore, these mice also showed a lower incidence of other age-related illnesses such as osteoporosis, greater glucose uptake, or improvements in motor coordination.
When the researchers carried out these same experiments with a variety of mice that produce more telomerase—a protein that lengthens telomeres and protects chromosomes—they observed that these mice not only enjoyed better health but also lived up to 20% longer (though this was partially dependent on their genetic background).
“We believe that such a significant increase in longevity is due to the protective effect against cancer produced by caloric restriction—incidences fall by 40% if we compare them with the mice that produce more telomerase and have a normal diet—and, added to the presence of longer telomeres, this makes the mice live longer and better,” says Dr. Blasco.
She notes that there are more than 10,000 people in the world on some form of controlled caloric restriction, so the observation of these individuals will be decisive in discovering the effects of this type of diet on humans.
The study was published online this week in PLOS ONE, in a paper titled “Telomerase reverse transcriptase synergizes with calorie restriction to increase health span and extend mouse longevity”.