I know we’ve all probably done this at some point, but I have to ask, so here goes: Have you ever looked at yourself in the mirror and asked, “Wow, where did all of those new gray hairs suddenly come from?” Or, and I’m totally pulling this scenario out of thin air, but have you ever spent an entire Sunday taking heavy boxes of Christmas decorations out of storage and then crouching on your knees for hours while putting up Christmas lights only to wake up the next morning to find that, for the first time ever, your arms and legs are super sore?

According to a new study done by Stanford researchers, there’s a reason why we suddenly seem to notice or feel our aging all at once. In a study involving 108 people ages 25 to 75, researchers tracked “thousands of different molecules.” The results revealed that we age in “dramatic bursts” at specific ages. The first aging burst happens around 44 and the second one is around 60.

Somewhere in your mid-40s, you start noticing obvious signs of aging that seem to arrive overnight. You assume it was a gradual process that you just hadn’t noticed, but it sure as heck felt like it happened really fast. New research indicates that may very well be the case. A study from researchers at Stanford tracked thousands of different molecules in people age 25 to 75 and found that people tend to make two big leaps in aging—one around age 44 and another around age 60. These findings indicate that aging can actually happen in bursts.

“We’re not just changing gradually over time. There are some really dramatic changes,” said senior study author Michael Snyder, Ph.D, geneticist and director of the Center for Genomics and Personalized Medicine at Stanford University. “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 researchers assumed the mid-40s changes would be attributed to menopausal or perimenopausal changes in women influencing the overall numbers, but when they separated the results by sex they saw similar changes in men in their 40s.

“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,” said study author Xiaotao Shen, PhD, a former Stanford Medicine postdoctoral scholar who now teaches at Nanyang Technological University Singapore.

The study included 108 participants who submitted blood and other samples every few months for several years. The scientists tracked age-related changes in 135,000 different molecules—nearly 250 billion distinct data points—to see how aging occurs.

The study may shed light on the reasons for jumps in certain diseases and maladies at certain ages. For the 40-somethings, scientists found significant changes in molecules related to alcohol, caffeine and lipid metabolism; cardiovascular disease; and skin and muscle. For those in their 60s, changes related to carbohydrate and caffeine metabolism, immune regulation, kidney function, cardiovascular disease, and skin and muscle were found.

The study authors did note that lifestyle might play a role in some of these changes. For instance, alcohol metabolism may be influenced by people drinking more heavily in their 40s, which tends to be a period of higher stress for many people. However, the researchers added that these bursts of aging in the mid-40s and early 60s indicate that people may want to pay closer attention to their health around those ages and make lifestyle changes that support greater overall health, such as increasing exercise or limiting alcohol.

The research team plans to study the drivers of these aging bursts to find out why they happen at these ages, but whatever the reasons, it’s nice to know that the seemingly sudden onset of age-related woes isn’t just in our imaginations.

[From Upworthy]

I was talking about this study with two of my girlfriends last week. We all turned 40 within a few months of one another and all year, we’ve been comparing all of the pesky ways our bodies are changing and what not. Two of us are February babies and we have been pretty consistent in our experiences, from new aches and pains to middle-of-the-night anxiety to unannounced hairs that show up in new locations, and a whole new form of exhaustion. We all agreed that while having data like this come out makes us feel our mortality a bit more, it’s also somewhat comforting to know that there’s a biological reason for certain big aging milestones. It’s also nice to know that everyone else our age is going through the same changes at around the same time, which means we’re all in this together. All of this said, it really is so interesting to know just how much basic biology contributes.

Photos credit: Ala J Graczyk, Kampus Production and RDNE Stock project via Pexels