What’s the secret to looking and feeling younger? For some, it’s expensive surgeries. For others, it’s a change in health and wellness habits. But what does science say?

David Sinclair, a 53-year-old genetics professor and anti-aging researcher who claims his biological age is 10 years younger, swears by four key habits:

1. A plant-based diet and cutting out alcohol
2. Intermittent fasting
3. Reducing stress
4. Regular exercise

While these habits can certainly contribute to a healthy lifestyle overall, experts disagree about their link to longevity. For example, research is mixed on whether intermittent fasting can slow the aging process. But Sinclair, who is also the cofounder of Tally Health, a membership-based longevity platform that includes TallyAge testing, an at-home test to determine your biological age, says his habits have dramatically altered his life span.

“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,” Sinclair said in a recent interview with Insider. “So it’s never too late.”

In addition to a plant-based diet and cutting back on alcohol, Sinclair shared that he drinks one to two matcha teas per day and takes supplements that contain resveratrol, an anti-inflammatory compound most commonly found in red wine. But the jury is out on whether people can reap the same benefits in a pill form.

“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.”

Sinclair, however, maintains that these habits aren’t just about living longer, but making the most of healthy years.

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