Chris Hemsworth at high risk for Alzheimer’s from APOE4 genes

Chris Hemsworth’s “biggest fear” became a reality when the “Thor” actor found out he carries two copies of a dominant gene that puts him at a greater risk for Alzheimer’s.

Doctors say, however, that while the chances of the Australian developing the memory-stealing disease may be greater, he might be able to steer clear by maintaining a healthy lifestyle. 

The 39-year-old spoke of the shocking reveal in an interview with Vanity Fair, after undergoing a series of genetic tests.

The results showed that his DNA carries two copies of APOE4, the strongest risk factor gene for developing Alzheimer’s disease, according to the National Institute on Aging.

“It’s something that puts you at higher risk for developing Alzheimer’s disease. Most of us will have either none, one copy or two copies of APOE4. If you have two copies, you’re much more likely to develop Alzheimer’s, significantly more likely, but there are people who have two copies who still never get the disease,” Dr. Gayatri Devi, a neurologist at Lenox Hill Hospital, told The Post. 

Indeed, having two copies of the gene is rare — just one in four people carry a single copy, while 3% of the population have both, a study by the National Institutes of Health from 2021 found.

While particular genes can put someone at risk for developing dementia, including Alzheimer’s disease, APOE4 is the most significant gene for the progressive disease that destroys memory and other important mental functions. 

“Genetics is not your destiny — there are multiple other things besides genes [to consider] — environment, what you eat, how much you sleep, lifestyle, all of those go into the mix,” Devi said. “It’s cause for being more proactive to do things that prevent late onset of Alzheimer’s.”

Older age is the most common risk factor for Alzheimer’s, considering the number of people with the disease doubles about every five years for individuals older than 65, though many live until 90 without ever developing it, according to the National Institute on Aging.

Devi says preventive measures can include getting enough sleep every night, exercising for 45 minutes at least three times a week, getting ear and eye screenings, focusing on heart health and preventing bone fractures which can hinder mobility, socializing and put folks at risk for cognitive loss. 

Alzheimer’s hits close to home for Hemsworth, who is starring in the National Geographic show “Limitless.” The new docuseries explores the aging process.

His grandfather suffers with the disease, he told Vanity Fair.

“I haven’t seen him in a few years, but my other family members have and there’s some days where he’s quite joyful and gives you a big hug,” he told the magazine.

Finding out that he’s predisposed to Alzheimer’s has helped Hemsworth keep prevention top of mind.

“I went, ‘OK, great. I now have to work on this more.’ If you look at Alzheimer’s prevention, the benefit of preventative steps is that it affects the rest of your life. When you have preposition to cardiovascular heart disease, cancer, anything — it’s all about sleep management, stress management, nutrition, movement, fitness. It’s all kind of the same tools that need to be applied in a consistent way,” he said.