Middle age: A period of time marked by more gray hairs, some possible weight gain, a potential midlife crisis and — according to new research — two dramatic changes in humans at the molecular level.
The claim comes from a study published in August in the journal Aging of naturechallenging the idea that people age in a gradual manner. Instead, research shows that many molecules and microorganisms in our bodies increase or decrease significantly between the ages of 44 and 60 – ultimately creating the peaks of aging.
“Most people think that aging happens gradually, constantly and linearly,” the study’s senior author Dr. Michael Snydersaid Professor of Genetics and Director of the Center for Genomics and Personalized Medicine at Stanford University Health.
But “we don’t just change gradually over time; there are some really dramatic changes,” Snyder said in a press release. “The mid-40s turned out to be a time of dramatic change, as was the early 60s.” And that’s true no matter what class of molecule you’re looking at.”
And these molecular changes are not insignificant to our health – they have been observed in molecules related to cardiovascular disease, skin and muscle health, immune regulation and kidney function, among others.
Here’s what you need to know about the latest findings and what these aging peaks could mean for your overall health.
As we age, the risk of age-related diseases – cancer, Alzheimer’s disease, cardiovascular disease – increases. But that doesn’t always happen gradually, according to the researchers, who noted that the risk of Alzheimer’s disease and cardiovascular disease, for example, rises sharply in old age.
To examine this – specifically by analyzing molecular and microbial changes in the human body – researchers from Stanford University and Nanyang Technological University in Singapore used data from 108 participants between the ages of 25 and 75.
Those participants donated blood and other biological samples (stool samples, oral and nasal swabs) every few months for several years. From those samples, the researchers were able to track age-related changes in more than 135,000 different molecules and microbes in the participants’ bodies.
The analysis showed that most molecules and microbes underwent large changes in their abundance (increase or decrease) during two time periods: when people were in their mid-40s and early 60s.
The massive changes in the bodies of 60-year-olds weren’t entirely surprising to the researchers — Snyder noted that many diseases and phenomena associated with aging increase at that point in life. But the changes in the 40-year-olds — especially in men and women — were surprising.
“This suggests that while menopause or perimenopause may contribute to the changes seen 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 first author of the study Xiaotao Shen, PhDformer postdoctoral fellow at Stanford, said in a press release.
Although it is too early to know how these molecular changes affect aging, researchers have been able to determine which molecules are associated with which body functions, systems or diseases.
Molecules that showed extreme changes in the 40s, for example, were linked to alcohol, caffeine and lipid metabolism, as well as cardiovascular disease and skin and muscle health.
Meanwhile, molecular changes in the 1960s were linked to carbohydrate and caffeine metabolism, immune regulation, kidney function, cardiovascular disease, and skin and muscle health.
According to experts, these changes could show up as a reduced ability to metabolize caffeine and alcohol, suggesting that it might be wise to reduce your intake of those substances. People in their 40s and 60s may also see a higher risk of developing cardiovascular disease, and people in their 60s may benefit from supporting their immune systems.
Although aging is inevitable, experts say there are ways to “manage or slow some of the changes associated with menopause and aging,” Ronald DePinho, MDsaid a professor of cancer biology at the University of Texas MD Anderson Cancer Center Health.
The easiest way to do that is through lifestyle changes, DePinho said — that means staying active, eating and sleeping well, managing stress and avoiding smoking and excessive alcohol consumption.