According to a 2024 study on molecular changes associated with aging, people go through two sharp jumps, one at an average age of 44 and another around age 60.
“We don’t just change gradually over time; there are really dramatic changes,” explained geneticist Michael Snyder in August 2024, when the research was published. “It appears that midlife, around the age of 40 or so, is a time of dramatic change, as is the early 60s. And this is true regardless of the class of molecules we’re looking at.”
Snyder and his colleagues investigated the biology of aging to better understand what changes occur and how, with the goal of being able to prevent or treat them more effectively. They followed a group of 108 adults who donated biological samples every few months over several years, writes Science Alert.
Researchers have noted that in certain conditions, such as Alzheimer’s or cardiovascular disease, the risk does not increase gradually over time; it suddenly escalates after a certain age.
So they wanted to take a closer look at biomarkers of aging to see if they could identify associated changes.
Using the collected samples, the researchers looked for different types of biomolecules. The molecules studied included RNA, proteins, lipids and taxa from the microbiome of the gut, skin, nose and oral cavity, for a total of 135,239 biological features.
Each participant submitted, on average, 47 samples over 626 days, with the most faithful participant providing 367 samples. This impressive amount of data generated more than 246 billion data points, which the researchers processed, looking for patterns in the changes.
Snyder and his colleagues observed a distinct change in the abundance of many types of molecules in the human body in two clearly defined stages.
About 81% of all molecules studied showed changes in one or both steps. The changes peaked in midlife, around the age of 40 or so, and again in the early 60s, with slightly different profiles.
The midlife peak showed changes in molecules associated with lipid, coffee and alcohol metabolism, as well as cardiovascular disease and skin and muscle dysfunction.
The peak in the early 60s has been associated with carbohydrate and coffee metabolism, cardiovascular disease, skin and muscle, immune regulation, and kidney function.
The first peak, midlife, is usually when women enter menopause or perimenopause, but the researchers ruled out this as the main factor: men also showed significant molecular changes at the same age.
“This suggests that while menopause or perimenopause may contribute to the changes seen in women in their 40s, there are likely other, more important factors influencing these changes in both sexes,” explained metabolomist and first author Xiaotao Shen, a former Stanford researcher now at Nanyang Technological University in Singapore. “Identifying and studying these factors should be a priority for future research.”
The researchers note that the sample size is quite small and that they tested limited biological samples from people between the ages of 25 and 70. The study was published in the journal Nature Aging.
