Chris Hemsworth talks learning about his Alzheimer’s risk

Chris Hemsworth didn’t expect his latest project to change his life.

The actor is known for his on-screen superhero powers, but he put his real-life strengths to the test in his National Geographic docuseries “Limitless.” In the Disney+ show, the 39-year-old star faces death-defying challenges to discover how to live a longer and healthier life.

One of the episodes is about memory, in which he discovers he is genetically predisposed to Alzheimer’s disease. In a sit-down on Sunday TODAY with Willie Geist, the actor recalled learning about being at risk for the disease.

“They did a deep dive into my blood work and my genetics … and found some indications that put me in a very high category, a risk category, for Alzheimer’s,” Hemsworth told host Willie Geist. “It was a real shock.”

The discovery, he said, “became a wonderful motivator to make changes ... and pay attention to my sleep habits and further attention to my stress management."

In the fifth episode of “Limitless,” he discovers that his genetic makeup includes two copies of the gene APOE4, one from each of his parents. Studies have linked the gene to an increased risk of Alzheimer’s.

“The idea that I won’t be able to remember the life I’ve experienced or my wife (Elsa Pataky), my kids, is probably my biggest fear,” Hemsworth says in the episode.

According to a 2021 study by the National Institutes of Health, about 25% of people carry one copy of APOE4, and 2 to 3% carry two copies.

The father of three teamed up with the world's leading longevity experts to take on six of the toughest tests of his life, including navigating through the Outback, walking across a beam 1,000 feet above Sydney, Australia, crawling through fire and more.

“It was a real, sort of, wake-up (call),” he said. “If I continue in a sprint, then the finish line being death. One day I’ll be there and I’ll go, ‘Oh yeah, what just happened?’”

“I had no idea it was gonna teach me... that we get one shot at (life), as far as we know, and make the most of it,” he added.

In the docuseries, viewers will also see a more vulnerable side of the mighty Thor actor as he deals with the off-screen stress.

Dropping the veil on his Hollywood persona, he said, “was probably my biggest hesitation.”

“I’m used to being behind the mask of a character,” he said. “And to then play yourself and confront some things that are problematic... it was kinda like being in a therapy session at times, but without the rebuttal of the advice at the end of it.”

Fans might be surprised to see the way Hemsworth deals with stress. He noted that he can prep himself for an event, walk onstage, on a red carpet and be “in the zone.”

“I’m ready for it,” he said. “(Then the stress comes) when I go out into public and it catches me out of nowhere, or I’m sort of weaving through the crowd and it’s fine, no one’s really paying attention, I’m with my kids at a restaurant. Then they start flipping out. There’s a scene, and then people are watching. And then phones are coming out, and ... it triggers my fight or flight in a pretty intense way.”

Related: 5 common questions about Alzheimer’s — answered by a Harvard neurologist

Further elaborating on his high risk for Alzheimer’s, Hemsworth told Vanity Fair that “there was an intensity to navigating it.”

Longevity doctor Peter Attia didn’t want to tell Hemsworth the news on camera and suggested to show creator Darren Aronofsky that he call the actor and ask if he wanted his results to be in the show.

“It was pretty shocking because he called me up and he told me,” Hemsworth told the magazine. “It was a pretty brief conversation, all things considered. I hung up the phone and my parents were there, at the time. They were like, ‘What was that about?’ And I told them, and then they had a bunch of questions. I had a bunch of questions, but no one answered them. I wish I’d had a more intense follow-up with it because I didn’t really know what to think. I was like, ‘Am I supposed to be worried? Is this concerning?’”

The actor said he was offered a version of the episode where they didn’t talk about his results, but decided against it.

“I thought, ‘No, look, if this is a motivator for people to take better care of themselves and also understand that there are steps you can take—then fantastic,’” he said. “My concern was I just didn’t want to manipulate it and overdramatize it, and make it into some sort of hokey grab at empathy or whatever for entertainment."

“It’s not like I’ve been handed my resignation and this is what it is —and it’s up in a few months,” the actor said. “It’s not quite that situation, thankfully.”

“Limitless” is now streaming on Disney+.

This article was originally published on TODAY.com