Man in blue shirt, black pants, and sneakers running outside on a track.

It may start with nothing more than a tremor in one hand. But Parkinson’s disease, caused by the death of dopamine-­producing nerve cells in the brain that help control movement and norepinephrine-­producing nerve endings that control body functions, is progressive—leading to ever-worsening symptoms.

These can include shaking or trembling, limb and trunk stiffness or rigid­ity, and difficulty walking, speaking, and even swallowing. Most people with the disorder will also eventually develop some degree of mental decline or dementia.

While some people, including the actor Michael J. Fox, first notice symptoms in middle age or earlier, most people who develop Parkinson’s disease are older than 60.

More on Senior Health

And the numbers are predicted to rise in the U.S. Nearly 1 million adults here will face a diagnosis of Parkinson's disease by 2020, up from 680,000 in 2010, according to a recent projection from the Parkinson’s Foundation Prevalence Project.

This might be in part because life expec­tancy has increased, going from 69.7 in 1960 to 78.8 in 2015, according to the Centers for Disease Control and Prevention.

“More people today are successfully living to an older age, in which Parkinson’s disease is more likely to ­develop,” says Allison Willis, M.D., a neurologist and neuroepidemiologist at the University of Pennsylvania.

Although Parkinson’s disease, which ­appears to affect about 50 percent more men than women, is incurable, a growing body of research points to lifestyle strategies that may help cut risk. Here’s what we know now.

Exercise and Diet Benefits

Several studies suggest that more physically active people may be less likely to ­develop Parkinson’s disease. “The strongest evidence we have for prevention has to do with physical exercise,” says Rodolfo Savica, M.D., a neurologist at the Mayo Clinic. So “make sure you’re getting at least 30 minutes of vigorous exercise (like brisk walking or cycling) five times a week.”

More may be better. An analysis published in JAMA last fall found that men who added 10 hours of moderate to vigorous exercise (such as jogging and tennis) a week cut their Parkinson’s risk by 10 percent. Those who ­increased exercise by another 10 hours a week cut their risk by 17 percent.

Several studies have linked the Mediterranean diet—rich in fruits, vegetables, healthy oils, and fish—to a lower risk of Parkinson’s disease.

And some research suggests that regular coffee drinkers might have a lower risk of Parkinson’s, but that’s far from definitive. “If drinking coffee is something you like doing, keep doing it, but there’s not strong evidence to recommend it specifically for Parkinson’s prevention,” Savica says.

Living With Parkinson's Disease

A neurologist will typically diagnose Parkinson’s disease based on medical history, symptoms, and an exam to evaluate movement and reflexes.

If you have the signs noted at the beginning of this article or sleep problems, “restless” legs, constipation, and a reduced sense of smell, tell your doctor.

The earlier it’s diagnosed and treated, the better, says Alessandro Di Rocco, M.D., director of Northwell Health’s Movement Disorders Program in Great Neck, N.Y. “With proper management, it is possible to maintain a good quality of life for many years,” he says.

Exercise can help. High-intensity exer­cise, such as running on a treadmill for 30 minutes three times a week, may improve motor symptoms. Drugs are also used to raise dopamine levels in the brain. Levodopa (Rytary, Sinemet, and generic) can help control movement problems for many years, Di Rocco says.

For advanced Parkinson’s, deep brain stimulation, a surgical procedure in which electrical signals are sent to areas responsible for movement, might provide some relief.

Be aware that certain anti­cholinergic drugs, which may be prescribed for tremors, can worsen cognitive problems and reduce the effectiveness of dementia drugs such as donepezil (Aricept and generic), according to a study by Willis that was recently published in JAMA Neurology.

Older adults are more susceptible to anticholinergic side effects such as confusion, dizziness, and falls, she says. And those with Parkinson’s may be even more vulnerable.

Editor’s Note: This article also appeared in the February 2019 issue of Consumer Reports On Health.