Although our meals have a significant impact on how quickly our bodies age, there is more nuance to the link between the two than we previously realized.
Calorie restriction has been demonstrated to extend life in numerous animal experiments. In fact, calorie restriction seems to lessen a number of human aging indicators as well.
According to a comment from Waylon Hastings, a postdoctoral researcher at the Tulane School of Medicine who received his PhD in biobehavioral health from Penn State, “there are many reasons why caloric restriction may extend human lifespans, and the topic is still being studied.” “One primary mechanism through which life is extended relates to metabolism in a cell.
“When energy is consumed within a cell, waste products from that process cause oxidative stress that can damage DNA and otherwise break down the cell. When a person’s cells consume less energy due to caloric restriction, however, there are fewer waste products, and the cell does not break down as quickly.”
Our bodies must replicate the DNA found in the worn-out cells in order to produce new ones.
Our DNA is like a shoe lace; each strand has a molecular “cap” at the end to keep it from fraying or tangling. Each time DNA is duplicated to create new cells, these caps, known as telomeres, get a little shorter. Thus, one helpful measure of the biological age of our cells is the length of our telomeres.
The frequency of cell replication and, consequently, the rate at which our telomeres shorten can be influenced by a number of factors, including age, stress, disease, nutrition, and heredity. However, less is known about how calorie restriction affects human telomeres.
Hastings and associates at Penn State gathered information from the nationwide CALERIE research, the first randomized clinical trial of calorie restriction in humans, in order to investigate these consequences. Data from 175 subjects was analyzed by the investigators following a 24-month calorie restriction.
Isan Shalev, an associate professor of biobehavioral health at Penn State and the study’s senior author, stated in a release, “We hypothesized that telomere loss would be slower among people on caloric restriction.”
What they discovered, though, was less clear-cut. The participants really lost their telomeres more quickly after a year of calorie restriction than those on a regular diet. But after two years, when the subjects’ weight reached a stable level, their telomere loss slowed down.
Those on calorie-restricted diets ended up with nearly the same length telomeres as those on a typical diet after the two-year period.
“This research shows the complexity of how caloric restriction affects telomere loss,” Shalev stated.
To find out if a further year of calorie restriction would result in a statistically significant difference in the participants’ biological aging, more research is needed. The CALERIE study has, however, emphasized a number of additional advantages of calorie restriction on human health, including a decrease in “bad” cholesterol and blood pressure, despite the ambiguity of these results and the complicated link between telomere length and calorie consumption.