Aging has traditionally been viewed as synonymous with a steady decline in health, but recent research unveils a more complex picture.

In fact, aging is not gradual, but rather surges at key stages of life, particularly during our 40s and 60s, due to dramatic shifts in our molecules and in the microorganisms that we host, according to researchers at Stanford Medicine who published a new study in Nature Aging.

The researchers analyzed how biomarkers—molecules such as RNA and proteins that reflect biological changes—shift across distinct five-year intervals in people aged 25 to 75.

Unlike standard medical evaluations, which might involve only 15 to 20 measurements, the researchers made “tens of thousands of measurements.” They found that biomarkers change most dramatically during two key periods in our lives: the mid-40s and the early 60s.

The researchers found observable changes related to cardiovascular disease and other health issues. This is important because acknowledging such changes can lead to actionable steps for improvement, Michael Snyder, chair of genetics at Stanford Medicine and the study’s senior author, told The Epoch Times.

He added that understanding these specific periods of change could help in developing interventions to mitigate the effects of aging.

2 Key Periods of Change

Of the thousands of molecules and microbes the researchers followed in their investigation, about 81 percent exhibited significant nonlinear changes, meaning they changed more at certain ages than at others. Only around 7 percent changed at a constant rate as study participants aged.

The study tracked participants over periods ranging from two to seven years. Previous findings from this same group of volunteers showed that people’s kidneys, livers, metabolisms, and immune systems aged at different rates.

The researchers analyzed 5,405 samples from 108 participants, encompassing more than 135,000 biological features, including gene activity, proteins, metabolites, and microbiomes. This culminated in a total of nearly 250 billion distinct data points.

When the researchers analyzed clusters of molecules showing the most significant changes, they identified the two critical periods of the mid-40s and early 60s, during which these transformations were more pronounced.

Around age 40, the following was observed:

• Changes in molecules indicated a reduced efficiency in alcohol, caffeine, and fat metabolism.
• The risk of cardiovascular diseases increased as platelets and proteins involved in blood clotting became impaired.
• Skin cells and proteins became dysregulated, potentially impairing skin structure and elasticity.

The following occurred around age 60:

• Molecular changes indicated further reduced efficiency in metabolizing caffeine and essential fatty acids. Unsaturated fat biosynthesis also decreased.
• Glucose metabolism was affected, suggesting elevated insulin resistance.
• Kidney function declined, as indicated by higher blood urea nitrogen levels, which show the kidneys are becoming less effective at filtering waste from the body.
• Cardiac issues increased due to a rise in plasma levels of phenylalanine, an essential amino acid associated with heart problems.
• Higher levels of cytokines, proteins that regulate the immune system, showed that the immune system weakens.

Individuals in their 40s should heed changes in lipid metabolism and consider cutting back on fatty meals, Snyder suggested. Similarly, for those in their 60s, monitoring kidney function and increasing water intake could be beneficial.

Snyder pointed out that these insights underline the importance of recognizing and addressing biological changes to manage health effectively as we age.

Overall, people in both age groups should consider exercising more to support heart health and preserve muscle mass. In one’s 40s, it’s also a good idea to drink less alcohol, since the body no longer metabolizes it as well, Snyder added.

The major changes seen in people’s mid-40s surprised Snyder and his team.

“I don’t know that I would have necessarily known that there’d be such a big period of change [in] people at their mid-40s,” Snyder said.

The researchers first thought that menopause or perimenopause might be causing these changes in women and affecting the overall results. However, when they looked at the data separately for men and women, they found that men in their mid-40s experienced similar changes. “[In women, people might think] maybe it’s all due to women hitting menopause,” Synder said. “But it turns out the same thing’s there, whether it’s male or female.”

Study first author Xiaotao Shen, a former Stanford Medicine postdoctoral scholar, addressed this issue in a press release:

“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. Identifying and studying these factors should be a priority for future research.”

The research team plans to explore the drivers of these clusters of change. Snyder, who is also the author of the book “Genomics and Personalized Medicine: What Everyone Needs to Know,” said that the study is a step toward moving beyond generic advice like “exercise more” or “eat better” and creating personalized aging profiles that pinpoint exact health risks.

”By understanding these patterns ... you can take action on it,” he said.