Mind & Body

Americans Are Aging More Slowly Than Ever

Until we finally upload our brains to the cloud, human beings are never going to stop aging. But we might be able to slow it down. In fact, that's already happening for at least some people in the United States — but we're not sure how long the trend can continue.

Trading Ages

According to a study published in March 2018 by Morgan E. Levine of Yale University and Eileen M. Crimmins of the University of Southern California, Americans from all walks of life aren't just living longer — they're aging more slowly than they did 20 years ago. The key is in the difference between chronological and biological age. You celebrate your chronological age on your birthday every year, but your biological age represents the actual wear and tear that your body has endured. You can even get an estimate of your biological age without going in for a checkup by taking this "RealAge" test online — it was designed by Dr. Michael Roizen of the Cleveland Clinic, and it's been one of the internet's favorite digital health tools since 1999. (Fair warning: you need to create an account in order to take the test.)

In any case, you might think of biological age as how old your body seems. Online tests like the one above are based largely on self-reported behaviors instead of harder data, but they can still be useful. For example, if you report being a regular smoker, for example, the tests increase your calculated age to factor in the effects of the cigarettes. But by using data from the CDC's National Health and Nutrition Examination Survey (NHANES), which combines self-reports with actual data from medical exams, researchers were able to gather information from two time periods: 1988 to 1994, and 2007 to 2010. They focused on factors such as metabolism, organ function, albumin levels, and blood pressure, which allowed them to paint a far more accurate picture of biological age over time. Best of all, the picture they painted was pretty good news.

Life in Slow-Mo

According to the researchers, Americans are aging more slowly than ever before. The effect is more pronounced in some demographics than others. Male patients, in particular, seemed to be aging more slowly than those of a generation before them, and the effect was even more strongly pronounced in men from both the oldest and the youngest groups examined. It makes some sense that the oldest men's aging would have slowed the most — making better decisions when you're young pays off more and more as time goes by. The fact that the effect also turned up in the youngest men adds an interesting wrinkle to the study that's probably worth further investigation.

It's important to notice that, although men seem to be slowing their aging more than women are, that doesn't necessarily mean that men are getting healthier than women are. Many of these improvements can be ascribed to changes in smoking, obesity, and medication use — if the men from the '80s and '90s had more unhealthy risk factors, then they also had more opportunities to make better choices. According to the study's lead author Morgan Levine, that could mean that young women won't see as much of an improvement in their life expectancy as men of the same generation, or it could mean that women are closer to the limits of human life expectancy than men are.

But the most important takeaway about the slowing rate of aging is that it corresponds with an already observed increase in lifespan. If people were living longer but aging at the same rate, it could spell big trouble for society in the form of increased medical expenses, more late-life health emergencies, and lower overall quality of life in the twilight years. The fact that aging is slowing means that people are living longer because they're living healthier lives, not because medical technology can better overcome poor health.

Your lifespan is curiously tied to where you live. Check out Dan Buettner's seminal work "Blue Zones: 9 Lessons for Living Longer from the People Who've Lived the Longest" to find out why people from a few select communities around the world live longer than anywhere else. We handpick reading recommendations we think you may like. If you choose to make a purchase through that link, Curiosity will get a share of the sale.

Can Science Stop Aging?

Written by Reuben Westmaas April 20, 2018

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