Almost 1,000 years after scientists discovered cutting calorie intake is capable of extending the lifespan in animals, a new study has been released that explains why. Researchers at the “Lewis Katz School of Medicine” published a finding in Nature Communications, explaining that changes in the epigenome are associated with aging. The investigators further stated that restricting calorie intake can slow down this changes which ultimately increases longevity.
A Breakdown of the Calorie Intake Theory
The scientists have found that epigenetic drift is characterized by gains and losses in DNA methylation. These alterations occur more in mice than monkeys and faster in monkeys than humans. These findings explain the reason the average mice lives only 2-3 years, the monkeys around 25 years, and the humans between 70-80 years.
DNA methylation affects mammalian genes and acts as a bookmark for when genes should be used, a phenomenon called epigenetics. Methylation patterns change throughout life and increase in some parts of the genome while decreasing in others.
Dr.Issa who is part of the research team made the discovery after studying the methylation patterns on the DNA in blood found from people of different age groups. Dr. Issa’s team studied three species- mice, monkeys, and humans. Mice were aged between a couple of months to about three years, while monkeys were aged between a few months to 30 years, and humans were between their early stages of development in the womb to 86 years. Age related differences in DNA methylation were examined using deep sequencing technology which showed distinct patterns. Gains in methylation were found in older species at genomic sites that were unmethylated in youthful species and vice versa.
Further examination discovered great losses in gene expression in genomic regions which were increasingly methylated with age. On the other hand, regions which had been less methylated, had increased gene expression. It was also found that species with rapid and high levels of epigenetic changes had a short life span.
Summing it Up
The research has important implications in health studies, with recent findings suggesting that high amounts of epigenetic drift raises one’s risk of suffering from age-related illnesses, including cancer. Though Dr. Issa admits that their team was the first to raise the idea of altering epigenetic drift as a means of modifying the risk of disease, they still do not have the answers as to why epigenetic drift is slower in some individuals and faster in others. Dr Issa’s team is hoping to find additional factors that affect methylation drift so that they may alter them to prevent age related diseases.