We know the body changes over time, but new research suggests those shifts may be more sudden and staggering than previously thought.
A new study from Stanford Medicine reveals that many of the body’s molecules and microorganisms starkly rise or fall in numbers at two specific times — ages 44 and 60.
Researchers drew this conclusion after assessing thousands of molecules — including RNA, proteins and metabolites — and their microbiomes, the collection of bacteria, viruses and fungi that live on and inside us, in people 25 to 75 years old.
Researchers found that 81% of the molecules studied displayed non-linear fluctuations, meaning they underwent more change at certain times than others. The findings were published Wednesday in the journal Nature Aging.
Michael Snyder, chair of genetics and the study’s senior author, imparts, “We’re not just changing gradually over time; there are some really dramatic changes. It turns out the mid-40s is a time of dramatic change, as is the early 60s. And that’s true no matter what class of molecules you look at.”
Researchers believe these dramatic changes are reflected in significant transformations within the body.
The research team was inspired to study the effects of molecular and microbial shifts after observing that the risk of developing age-related conditions like Alzheimer’s disease and cardiovascular disease is a sharp, rather than a steady, rise.
For those in their 40s, molecular changes were seen in the number of molecules related to alcohol, caffeine, lipid metabolization, cardiovascular disease and skin and muscle.
For those in their 60s, changes were related to carbohydrate and caffeine metabolism, immune regulation, kidney function, cardiovascular disease and skin and muscle.
Among the 108 study participants, researchers identified four “ageotypes,” indicating that the kidney, liver, metabolism and immune systems age at differing rates in different people.
When researchers searched for clusters of molecules with the largest fluctuation in amount, they found these changes occurred the most at two intervals: when people reached their mid-40s and early 60s.
The mid-40s cluster surprised scientists who initially assumed that menopause or perimenopause was directing these changes in women, thereby skewing the group. However, when they divided the study group by sex, they discovered that the cluster shift affected men equally.
Xiaotao Shen, a former Stanford Medicine postdoctoral scholar and the study’s first author, expounds, “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.”
As Shen suggests, more research is needed to explore the driving force of these sudden changes, whether the results are the product of behavioral or biological factors.
Regardless of causation, researchers recommend paying particular attention to your health in your 40s and 60s, perhaps increasing exercise and decreasing alcohol consumption to live in better accordance with these biomolecular shifts.
As Snyder maintains, “I’m a big believer that we should try to adjust our lifestyles while we’re still healthy.”
