We often think of aging as a steady, downhill slope, but a new study suggests aging happens in two distinct bursts—in our mid-40s and again around age 60—when massive shifts in crucial molecules involved in metabolism and other critical processes occur. These shifts may explain why our disease risk and other hallmarks of aging tend to spike at these pivotal times in our lives.

The study involved 108 adults aged 25 to 75 years living in the U.S. Researchers assessed changes in 135,000 molecular markers in the participants' blood, feces, and bodily fluids for up to seven years, yielding more than 246 billion data points.

They found that molecular changes occurred in two massive bursts rather than gradually, with changes in cardiovascular health, lipids, and alcohol metabolism appearing around 44 years of age, followed by shifts in crucial biological processes such as immune regulation and carbohydrate metabolism around 60 years.

These findings suggest that the progression of aging and related diseases is marked by distinct phases at specific ages. Some lifestyle behaviors can delay the changes that drive aging. Learn more about these powerful habits in this episode featuring Dr. Rhonda Patrick.