Lately, the biggest news in Alzheimer’s has been around a new drug treatment that can slow cognitive decline by nearly 30% among people in the early stages of the disease. In coming months, the U.S. Food and Drug Administration is expected to make a decision about another such promising therapy.

But in addition to pharmaceutical interventions, which are expensive and require repeated infusions, making sustained lifestyle changes can also slow the progression of the disease, and possibly even prevent further decline, according to a new study.

In the trial, an intensive program of diet, exercise, stress reduction, and social interaction slowed the progression of cognitive decline as measured on standard tests for dementia, and even improved some people’s symptoms. The study was conducted by Dr. Dean Ornish, founder and president of the nonprofit Preventive Medicine Research Institute and professor of medicine at the University of California, San Francisco, and a team of scientists. It appeared in the journal Alzheimer’s Research and Therapy.

Previous studies have shown that moderate changes in lifestyle can lead to some slowing in cognitive decline, so Ornish and his team decided to test whether a more in-depth, formal program of behavior changes could slow brain changes even further. Ornish had previously developed the program to address heart disease risk and showed that the combination of improved diet, exercise, stress reduction, and social engagement could significantly lower the risk of atherosclerosis and heart disease.

“I have a unifying theory that many different chronic diseases share the same underlying biological mechanisms,” he says. “Those include inflammation, overstimulation of the sympathetic nervous system, changes in the microbiome…gene expressions, and immune system changes. That’s why what is good for the heart is good for the brain—these same mechanisms affect different conditions, and lifestyle choices can make them better or worse.”

In the study, 49 people with mild cognitive impairment or early Alzheimer’s dementia agreed to participate. Half made the lifestyle changes in Ornish’s program for 20 weeks, and the other half kept their normal habits (although the latter group was offered the opportunity to join the program after the study ended). Everyone provided blood samples so that the researchers could track changes in markers for Alzheimer’s and fecal samples to provide insight into their microbiome, or gut bacteria.

The program was easier to stick to in the study than it would be in real life. Twice a week, the researchers shipped three daily vegan meals and two snacks to people in the lifestyle change group and their partners. Those participants also did 30 minutes of aerobic exercise a day (mostly walking) and strength training at least three times a week. A stress-management specialist guided them in meditation, yoga, stretching, and relaxation exercises for an hour a day to improve their concentration and relaxation. Finally, these participants and their partners joined a support group three times a week to discuss any mental-health and emotional issues they were experiencing. They also took several vitamins and supplements, including omega-3 supplements, a multivitamin, and Lion’s mane mushrooms and probiotics for cognition.

Read More: Multivitamins Are Linked to Slower Brain Aging

By the end of the 20-week study, those who made the lifestyle changes showed statistically significant improvements in three of four standard cognitive tests and borderline statistically significant changes in the fourth test—compared to people in the control group, who showed worsening scores on all four tests.

While the improvements were small, Ornish says that 20 weeks is a relatively short period of time, and that other metrics further support the encouraging changes recorded on those tests. For one, the more closely people adhered to the lifestyle changes, the better their improvements; another was that blood markers for amyloid protein, which builds up in the brains of Alzheimer’s patients, showed positive changes similar to those recorded in people taking the new Alzheimer’s medication, lecanemab.

“This is the first step,” says Ornish. “This is not the study to end all studies. But it shows for the first time that intensive lifestyle changes can improve cognition and function in patients who have Alzheimer’s.”

Ornish hopes these results will encourage insurers to cover the program; Medicare already does for heart disease. He also hopes the findings will give more people access to a way to slow their disease or even prevent it from progressing. “This was designed as an intervention so anybody can do it,” he says. “We didn’t want concierge medicine. And we have data on 15,000 people who have done the cardiac program, which is exactly the same. Bigger changes in lifestyle can lead to better clinical outcomes, cost savings, and better adherence.”

Read More: Physicians Are Dramatically Underdiagnosing Early Cognitive Decline

To those who question whether people can stick to a vegan diet, exercise regimen, stress management, and support group schedule, Ornish points to the power of positive versus negative messaging when it comes to making behavior changes. “When people feel better and see changes, that reframes the motivation from fear of dying to joy of living, which is more sustainable,” he says. Anecdotally, some people participating in the program reported being able to pick up reading again, which they had to give up when their Alzheimer’s made it impossible to follow story lines and remember characters, Ornish says.

“When you make changes that make people feel so much better quickly, it gives them hope again that they can do things they were told they would never do again,” says Ornish.

His team next hopes to continue following this group of patients, as well as include more people from diverse backgrounds to bolster the data. He is also eager to see how the program might work together with lecanemab and any other drugs that may get approved for Alzheimer’s.