Though we like to focus on how growing older can look, it’s hard not to have Alzheimer’s disease on your radar. Maybe you’re witnessing its devastating impact on a family member, or you’re worried about your own risk as years pass—or both. Unfortunately, the fear is not unfounded: “Forty percent of all Americans will suffer from Alzheimer’s disease by the time they’re 85,” says Mark Liponis, M.D., . That number is hard to ignore. If we can leave you with one takeaway, however, it’s that Alzheimer’s is not simply the price you pay for having more birthdays.

Yes, it’s true that part of the reason for this grim statistic is that Alzheimer’s is a complicated, poorly understood disease that doesn’t have a single, easy-to-identify cause. It’s the description of a brain that has become damaged and scarred, resulting in memory problems, behavior changes and other cognitive issues. But more and more evidence shows that chronic inflammation, a process in which one’s immune system gets stuck in the “on” position and causes damage, could be behind some Alzheimer’s cases. For example, women who have the highest levels of a particular inflammation biomarker in their blood are 10 times more likely to develop Alzheimer’s disease than women with the lowest levels. And researchers have found that some anti-inflammatory medications can reduce the likelihood of Alzheimer’s by 70 percent.

While some reasons for elevated inflammation levels are in your control, others are not. Brain injuries and systemic infections may cause inflammation in the brain that contributes to Alzheimer’s, for example. And inadequate blood flow to tissues (a condition known as ischemia) is also closely tied to the disease: “If circulation is impaired, tissues can be deprived of adequate oxygen and nutrients, causing them to become inflamed,” Dr. Liponis explains. We don’t know exactly know how inflammation promotes Alzheimer’s. But in the brain, inflammatory cells (microglia) appear to be playing an active role in brain inflammation, which is a hallmark of the disease.

The symptoms of inflammation in the brain are often silent until a large number of cells are damaged and memory loss is noticeable. The key, therefore, is to act before symptoms are evident. Perhaps the most important thing you can do is exercise. It has long been reported that people who are physically active have less inflammation and a lower chance of developing Alzheimer’s disease than those who are sedentary. Exercise helps keep blood flowing, counters age-related reductions in neural connections and promotes the release of chemicals that protect the brain.

Exercise doesn’t have to be strenuous or a giant commitment to be effective. Aim to work out for 30 to 60 minutes several times a week, and pair that routine with an inflammation-fighting diet that’s rich in colorful produce and omega-3 fatty acids. There’s an added benefit to a healthy diet and exercise plan: weight loss. Fat cells, particularly those that settle around the belly, promote inflammation. If you lose some weight, you’ll lower your levels of inflammation and your risk of Alzheimer’s, heart disease and other health concerns.

“In medical school we were taught that the brain reaches maturity, then it begins a slow process of decline,” Dr. Liponis says. “Now we know that if inflammation can be reduced or eliminated, healing and regeneration in the brain can follow—and that’s great news for the future of Alzheimer’s disease.”