Or, technically speaking, my biological age. Compared to chronological age, “bio-age” may better reflect how well your body is resisting Father Time. Bio-age is based on chemical marks, or epigenetic changes, that affect how genes are expressed. Because epigenetic changes accumulate over time, they may show how fast we’re aging. In recent years, scientists have used machine learning and algorithms to identify which epigenetic changes reveal the most about the aging process.

Many companies offer bio-age tests. But Elysium’s, called Index, caught my eye because it provides specific bio-ages for the heart, brain, kidneys, and six other bodily systems, which age at different rates. Index was developed by Elysium with epigenetics expert Morgan Levine and benefits from new technology that looks at many more sites of epigenetic changes, says CEO Eric Marcotulli. “We think it’s more precise and reproducible than any other clocks out there,” he tells Fortune.

That includes Elysium’s previous version of Index, which offered one overall age, not specific system ages. I took it back in 2020, getting a bio-age four years younger than my actual age. That result seemed to reflect my nutritious food choices and regular tennis game; diet and exercise are keys to healthy aging.

But a big factor has changed since 2020: I’ve switched my line of work from policymaking to editing and writing, roles that give me a greater sense of purpose but also inspire longer, more grueling work. How has having more purpose and more stress at work affected my bio-age? 

Life purpose supports longevity, research shows. “Generally, people who are higher in purpose have better walking speeds, grip strength, and lung function” as they age, says Angelina Sutin, a Florida State psychologist who studies well-being across lifespans.

On the other hand, striving for perfection at one’s vocation can cause lots of stress, which is ruinous for health. In an old policy job, when my boss assigned a task, sometimes he’d recommend, apologetically, “Don’t kill yourself on this.” I happily complied. These days, though, I take fewer shortcuts, frequently working late into the evening. Then I flip on the Tennis Channel for an hour of recuperative vegetation before bed.

“There’s a lot of evidence to support that stress increases your pace of aging,” Sutin says. But purposeful stress is unique, she explains. With some notable exceptions, people who are high in purpose handle their stress better. That’s partly because they view it as necessary to an important goal, Sutin says. Stressors become unbearable when we can’t control or find meaning in them—like childhood abuse—driving faster epigenetic aging.

Stress isn’t the only consideration. Highly driven people with desk jobs, such as myself, sit with their computers all day, which could harm health more than smoking. Based on her research, though, Sutin thinks many dedicated workers aren’t so sedentary after all. “People who are purposeful need a certain amount of activity to get things done,” she says.

In my case, Index would provide the final word. Or maybe not. Epigenetic tests have measurement errors, says Daniel Belsky, a Columbia University epidemiologist. In big groups, these tests are useful to track how lifestyle changes, like caloric restriction, impact aging; the margin of error becomes less important when spread among thousands of people. But “we don’t know if any of these measures are ready for individual level analysis,” Belsky says.

He’s developed one such measure, DunedinPACE, which draws from research on over 1,000 people born in the late 1970s, looking closely at how their bodies have aged over time. “Do you get some information out of it? Probably,” Belskey says. “Tests such as Dunedin and Levine’s [measures] have much lower technical error than several others. But all of these tests share the same limitation for use in individuals.”

Research on Index’s new technology has been published in Nature Aging, and Marcotulli says its age measurements are “n of 1 accurate” and actionable—correct and useful for any given person, not just across groups. Index uses the sites of epigenetic changes that correspond to the most relevant blood measures for each of the nine systems, such as ALT for the liver, explains Leonard Guarente, an MIT biologist and Elysium’s chief scientist and co-founder. Because these blood measures are affected by our daily habits, each Index number “will link to a health status that can be changed and influenced by lifestyle,” Guarente says.

The nine systems don’t cover everything; future versions of Index will capture more aspects of aging, and “that’s where we’re starting to get into personalized medicine,” Marcotulli says.

When I got my results, my overall biological age was lower than my actual age, as in 2020. But a few of my system ages were higher, such as my hormone system, including glands like the thyroid and pancreas.

These glands are affected by—you guessed it—stress. Instead of searching for easier jobs to get on track for super-aging, I asked my seven-year-old for guidance. He often sees things more clearly than I do. “Maybe work is more important to you than living a long time,” he tells me.

Maybe, but I’m not ready to accept the either/or proposition. In that spirit, here are expert tips to mitigate work stress for healthy aging:

Cultivate optimism. People who are optimistic, either by nature or as a developed trait, tend to live longer, according to research by Lewina Lee, a Boston University psychologist. “They have more flexible cardiovascular acute stress response profiles,” Lee says.

A new study led by Harvard researchers finds that optimistic people have epigenetic changes linked to lower risk ofage-related diseases. Try looking on the bright side at work. It could go a long way.

Achieve optimal stress. It’s key to identify optimal stress levels, Sutin says. According to the Yerkes Dodson law, each individual has an ideal amount of pressure that brings out their best work. Pushing past that threshold causes excess anxiety, undermining performance.

You can manage work stress by enjoying meditation, mini rest breaks, and vacations. Lee suggested another strategy: practice hormesis, purposely exposing yourself to stressors, such as freezing cold showers, to strengthen your stress response.

Self-assess. Besides bio-age, other measures of age-related health and stress are supported by decades of research, Belsky says. One hallmark of aging, inflammation, is revealed through common blood tests of c-reactive protein. Inflammation is one of Index’s nine systems, with epigenetic age tracking to data from blood tests, but the underlying numbers can also be informative.

Then there’s blood pressure, glycated hemoglobin, lung function measurements, etc—the list goes on, and it gets complicated. Together, these measures comprise a “pretty good toolkit” but “tend to require a great deal of expertise to interpret,” Belsky says.

More accessible is heart rate variability, which reflects stress when measured through affordable sensors. When work stress drops my HRV, I take more mini-breaks.Among these other measures, bio-age is one thing to keep in mind. With more data, these tests will keep improving, and we’ll learn more about their accuracy in individuals, Belsky says. Until then, don’t shy away from highly meaningful work. If pursued in the right way, your vocation could add years of healthy living.