- While ageing is often seen as a steady progression, a new study from Stanford University has found that there are, on average, spikes in the process around the ages of 44 and the early 60s due to molecular changes.
- The study examined 108 participants who donated blood and other biological material over the course of years.
- Scientists aren’t sure if these moments of rapid ageing are biological, behavioural, or a mixture of the two.
While most people think of ageing as a steady decline, like a strong wind slowly weathering a stone, a new study from Stanford University – inspired by the observation that risks for things like Alzheimer’s diseases raise sharply with old age – claims that humans actually age in a much less linear fashion than we believed.
Published this week in the journal Nature Aging, scientists examined thousands of different molecules (specifically, the micro-universe of bacteria, fungi and viruses that live within us and on our skin) in subjects between the ages of 25 and 75. The team found that the numbers of these various molecules changed drastically around two specific ages on average.
“We’re not just changing gradually over time; there are some really dramatic changes,” Stanford University’s Michael Snyder, a professor of genetics and the study’s senior author, said in a press statement. “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.”
The data set used in the study was derived from 108 individuals who donated blood and other biological material over the course of years. This allowed the researchers to track certain molecules (such as RNA, proteins, and metabolites), while also keep tabs on the make-up of each participant’s microbiome. With 135,000 molecules being tracked for 108 participants several times over the course of years, the scientists ended up with around 250 billion distinct data points.
By pouring over this data, Snyder and his team concluded that 81% of molecules showed non-linear ageing characteristics, meaning that they changed more rapidly at certain ages rather than steadily changing as the years pass by. By finding the largest clusters of changes averaged across the population, they found that people tend to undergo more rapid aging around the ages of 44 and the early 60s. However, the age periods weren’t exactly the same. For example, an increase in molecules related to cardiovascular disease were found in both age ranges, but those impacting immune function were largely seen in the early 60s population.
While the researchers admit that a shift in the early 60s trends with other data that shows how disease risk increases around this age, the data point related to the mid-40s came as a bit of surprise. While their first instinct was to consider whether this was caused by women experiencing perimenopause and menopause, the data shows no discernible difference between males and females in this age range.
“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, a co-author of the study, said in a press statement. “Identifying and studying these factors should be a priority for future research.”
The team hasn’t discerned if these changes are purely biological, behavioural, or a mixture of both, but evidence points to at least some of these changes being influenced by external factors outside the body. For example, in the mid-40 cohort, the study notes changes in the number of molecules related to alcohol, caffeine and lipid metabolism. Snyder hypothesises that this could be driven in large part by the fact that the mid-40s is often viewed as a very stressful period of life, when many are raising families.
Whatever the factors, this study highlights the importance of both focusing on health around these two age groups and putting healthy practices in place before you reach them. After all, nothing delays the reaper quite like diet, exercise and a good night’s sleep.
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