A 53-year-old longevity researcher says his 'biological age' is a decade younger thanks to 4 daily habits — but the science behind them is mixed

• David Sinclair, 53, says his biological age is a decade younger than his actual age.
• The longevity researcher swears by supplements, intermittent fasting, less stress, and exercise.

David Sinclair, a Harvard biologist and anti-aging researcher, has spent more than 53 years on the planet. He has spent several decades of those years making key discoveries in longevity science, building biotech companies, and securing dozens of patents.

But Sinclair told Insider that according to components of his DNA that reflect the aging process, he's a full decade younger than his ID suggests. That puts him in the top 2% of his peers, he said.

He wasn't always like this. Sinclair said that in his 30s, he overate, over-drank, and was overweight. But making lifestyle changes like adopting a plant-based diet and cutting out most alcohol has made a big difference in his projected lifespan — according to him.

"My calculated biological age has been going down for the past decade or more to a point where I'm predicted to live at least a decade longer than I would have if I hadn't done anything," he told Insider. "So it's never too late."

The concept of biological age and how to estimate it is controversial, and Sinclair has a vested interest in promoting anti-aging as the co-founder of Tally Health, a platform that allows consumers to repeatedly test their "TallyAge" and make the company's recommended lifestyle changes to pause or reverse it. Sinclair told Insider he has calculated his own biological age over the years using many of the same theories and studies Tally Health is based on.

Still, many of Sinclair's habits are well-known to support healthy aging. Here's what he told Insider keeps him young.

Sinclair said longevity starts with nutrition

Sinclair, author of the 2019 book "Lifespan: Why We Age and Why We Don't Have To," said anti-aging starts with nutrition. He drinks one to two green-tea matchas daily, prepared by his partner, nutritionist and celebrity chef Serena Poon.

"That's got molecules in it that will prevent cancer, among other things" like anti-inflammatory properties, he said. Some older research has shown, for example, that green tea consumption might be linked to a lower risk of stomach cancer.

Sinclair also said he takes supplements (like those sold on the Tally Health website) that contain resveratrol, which his team's research has shown can extend the lifespan of organisms like yeast and worms.

While the compound, famously found in red wine, is known to have anti-inflammatory, anti-cancer, heart health, and brain health benefits, the research is mixed on if or how well such benefits can be achieved in humans through a pill.

"As soon as I see resveratrol in anybody's supplement stack, they lose all credibility," University of Washington longevity researcher Matt Kaeberlein told Insider. "It's been disproven over and over and over in the longevity field, at least."

But for Sinclair, who said he's been taking such supplements since his early 30s, "so far, so good."

Sinclair tries to practice intermittent fasting

Sinclair said he's also cut back on the frequency of his meals. "I try to pack my main meal into a few hours a day, whenever possible," he told Insider. "And that period of fasting has also had great benefits on my estimated biological age."

Emerging research suggests intermittent fasting may help increase longevity due to the way it seems to affect cellular aging and reduce the risk of certain diseases. But studies on exactly how, how well, and if intermittent fasting's benefits differ from those seen from calorie restriction are ongoing.

Reducing stress and avoiding jerks is important

Sinclair also said stress management, including setting aside "quiet times" during the day, supports healthy aging. "I don't stress so much about problems," he said. "I do surround myself with people who are not jerks, increasingly."

Indeed, research shows that not only does stress exacerbate physical health problems, like heart attack risk, but it also seems to have negative consequences to the lifespan on its own.

In January 2022, Yale psychiatrist Dr. Zach Harvanek told Connecticut Public Radio about his team's 2021 study that found stress contributes to aging outside of its impact on disease — and that stress-reduction strategies can help combat that.

"The most surprising aspect of the study is that resilience factors, like emotion regulation, can protect us not just from the mental effects of stress, but also from the effects of stress on our physical health," Harvanek said.

Exercise is also key to living longer

Sinclair said he could be better at incorporating aerobic exercise into his routine at least three times a week, but he uses a standing desk to cut back on sedentary time.

While one large and widely-cited 2012 study suggested that sitting for more than eight hours a day is as deadly as regular smoking, it also seems 60 to 75 minutes of moderately intense physical activity a day can off-set those risks, according to the Mayo Clinic.

Sinclair said prioritizing habits that promote longevity isn't just about living longer, it's about extending your "healthspan," or maximizing your healthy years.

"Nobody wants to be sick for a decade or have cancer that drags on or be frail," he said. "What we're really talking about is preventing those things, or squeezing them into the last bit of life."