If you’ve noticed a sudden accumulation of wrinkles, aches and pains or a general sensation that you’ve aged almost overnight, there may be a scientific explanation. Research suggests that rather than being a slow and steady process, aging occurs in at least two accelerated bursts.
The study, which tracked thousands of different molecules in people between the ages of 25 and 75, detected two major waves of age-related changes at around 44 and again at 60. occur at certain ages.
“We don’t just change gradually over time. There are some really dramatic changes,” said Prof Michael Snyder, a geneticist and director of the Center for Genomics and Personalized Medicine at Stanford University and senior author of the study.
“It turns out that the mid-40s is a time of dramatic change, just like the early 60s—and that’s true no matter what class of molecules you’re looking at.”
The research tracked 108 volunteers, who submitted blood and stool samples and skin, mouth and nose swabs every few months for between one and nearly seven years. Researchers assessed 135,000 different molecules (RNA, proteins and metabolites) and microbes (the bacteria, viruses and fungi that live in the gut and on the skin of the participants).
The abundance of most molecules and microbes did not shift in a gradual, chronological fashion. When the scientists looked for groups of molecules with the biggest shifts, they found that these transformations tended to occur when people were in their mid-40s and early 60s.
The mid-40s aging rise was unexpected and initially assumed to be a result of perimenopausal changes in women skewing results for the entire group. But the data showed that similar shifts also occurred in men in their mid-40s.
“This suggests that while menopause or perimenopause may contribute to the changes observed in women in their mid-40s, there are likely other, more significant factors influencing these changes in both men and women,” said Dr Xiaotao Shen, ‘ a former postdoctoral scholar at Stanford medical school and first author of the study who is now based at Nanyang Technological University Singapore.
The first wave of changes included molecules linked to cardiovascular disease and the ability to metabolize caffeine, alcohol and lipids. The second wave of changes included molecules involved in immune regulation, carbohydrate metabolism and kidney function. Molecules linked to skin and muscle aging changed at both time points. Previous research has suggested that a later increase in aging may occur around the age of 78, but the latest study could not confirm this because the oldest participants were 75.
The pattern fits previous evidence that the risk of many age-related diseases does not increase incrementally, with Alzheimer’s and cardiovascular disease risk showing a sharp rise after 60. It is also possible that some of the changes could be linked to lifestyle or behavioral factors . For example, the change in alcohol metabolism may be the result of an increase in consumption in people’s mid-40s, which can be a stressful period of life.
The findings could help target interventions, such as increasing exercise during periods of faster muscle loss, the authors said. “I’m a big believer that we should try to adapt our lifestyles while we’re still healthy,” Snyder said.
The findings are published in the journal Natural aging.
