Massive Biomolecular Shifts Affect Humans During 40s and 60s

Molecules shift and change as we age — but often not in a linear fashion.

Have you ever suddenly felt “old?” Scientists have discovered that there may be a reason for this, particularly if it occurs in one’s 40s or 60s – a massive biomolecular shift.

Researchers studied thousands of molecules and microbiomes in people between the ages of 25 and 75, and found that rather than gradual change, they experienced a dramatic shift in their biomolecular makeup at the average ages of 44 and 60. Their findings were published by Nature Aging on August 14, 2024, in a paper titled “Nonlinear Dynamics of Multi-Omics Profiles During Human Aging.”

The scientists analyzed samples of blood and other biological material taken every few months from 108 individuals in California, allowing them to observe changes in more than 135,000 biological features over time. They found that about 81% of the molecules studied experienced transformation outside of a linear timeframe – most commonly, when people were in their mid-40s or early 60s. And while many women experience menopause-related changes during the earlier time period, researchers noted that these changes were not limited by gender.

Women and men experience similar biomolecular shifts in their mid-40s and early 60s.

“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,” Xiaotao Shen, an assistant professor at Nanyang Technological University Singapore and the study’s first author, told Stanford Medicine. “Identifying and studying these factors should be a priority for future research.”

The researchers had been inspired to study biomolecular shifts based on the dramatic increase in risk for developing conditions such as Alzheimer’s disease or cardiovascular disease after age 60, causing them to question a linear view of the aging process.

The study found that certain molecules and “functional pathways” were associated with these periodic shifts. In their mid-40s, participants experienced the most significant changes in their cardiovascular health and ability to metabolize alcohol and lipids, while their early 60s brought biomolecular shifts in immune regulation and carbohydrate metabolism. Changes in caffeine metabolism, as well as in skin and muscle, occurred at both points in time.

Michael Snyder, a professor of genetics at Stanford University and the study’s lead author, told Stanford Medicine that the study suggests people should take care of their health in their mid-40s and early 60s, whether that means cutting back on alcohol or exercising more to protect heart muscle.

“I’m a big believer that we should try to adjust our lifestyles while we’re still healthy,” Snyder said.