This is the key to staving off dementia, according to an MIT neuroscientist

It comes down to discipline.

That's according to MIT Professor Li-Huei Tsai, a neuroscientist who focuses on diseases like Alzheimer's and directs The Picower Institute for Learning and Memory. She told Insider that the keys to maintaining healthy brain function and memory as you age are no secret.

"I think people actually know what they should be doing to stay healthy and to preserve their memory," Tsai said.

She said that common expert advice — exercise, be socially and intellectually active, and maintain a healthy diet — are important to implement into our lives. The harder part is maintaining those habits.

"I think that if you just keep a routine, you know, you do it," Tsai said. "I mean, I think that's the only way to do it."

A recent study published in The BMJ that followed almost 30,000 people in China for 10 years found that those who followed more "healthy lifestyle factors" had slower memory decline than those who did not.

Researchers in the study looked at many of the same factors that Tsai called out: a healthy diet, regular exercise, regular social contact, cognitive activities, and abstaining from both smoking and alcohol.

Tsai is now working on a medical device that's intended to slow the progression of Alzheimer's disease. It creates a show of light and sound for the wearer, and is designed to stimulate their brain.

Tsai said she knows it's important to maintain her routine even when conditions are less than favorable.

"I just have to really discipline myself," she said. "For instance, exercise in the winter: it's really painful when you look at outside temperature below zero and there's ice and snow on the ground. I just try to discipline myself."