A new study found that taking as few as 3,000 to 5,000 steps daily can slow the decline of Alzheimer’s disease in people at increased risk by as much as three years. The study, published in Nature Medicine, involved older patients who had biological signs of the illness, but no cognitive symptoms.

The researchers also found that walking 5,000 to 7,000 steps daily slowed cognitive decline by 7 years, illustrating how exercise can benefit the brain, according to Nature.

“The very encouraging takeaway is that even a little bit of exercise seems to help,” said Dr. Wai-Ying Wendy Yau, a neurologist at Mass General Brigham and the study’s first author. She added that her research shows you don’t need to take 10,000 steps a day to reap the cognitive benefits of walking.

The 14-year study involved 300 participants between the ages of 50 and 90 years, some of whom had elevated levels of amyloid, a protein that forms toxic plaque in the brains of Alzheimer’s sufferers, according to the Financial Times. The more active participants who had amyloid plaque had slower cognitive decline and a slower buildup of tau during the study in which they were closely monitored. Tau is a protein found in neurons that forms tangles inside brain cells, which disrupts communication and contributes to cognitive decline in Alzheimer’s patients.

Physical activity didn’t slow the buildup of amyloid, however, but experts say that tau appears to play a more direct role in cell damage and death.  The study also showed that the cognitive benefit of exercise seems to plateau between 5,001 and 7,500 steps daily.

“We’re all working on better treatments, better drugs, but we can’t underestimate the value in these lifestyle factors that people can implement on their own to protect their brain health,” said Yau.

Nearly 7 million people live with Alzheimer’s in the U.S., and that’s projected to double by 2060. The disease is among the 10 leading causes of death in the U.S., according to the Centers for Disease Control and Prevention.

There is growing evidence that exercise is a modifiable risk factor for Alzheimer’s disease, along with other lifestyle factors such as nutrition. The new study adds to this research and although it doesn’t answer exactly why exercise reduces tau buildup and slows cognitive decline, Yau suggests that increased blood flow to the brain may play a role.