Your environment. It’s basically everything other than your genes, the pieces you inherit from your parents that make you who you are, from your hair color to your risk for disease, including Parkinson’s. And in people who live with Parkinson’s, environment and genes combine to cause disease.
You can’t change your genes, but you can modify your environment. Beate Ritz, MD, PhD, an MJFF-funded researcher who studies environment and Parkinson’s, tells us how.
Dr. Ritz is distinguished professor and vice chair of the Epidemiology Department at University of California Los Angeles (UCLA), where she holds appointments in the environmental health and neurology departments as well. She also co-directed, for a decade, the National Institute of Environmental Health Sciences (NIEHS)-funded UCLA Center for Gene-Environment Studies of Parkinson’s disease.
The Michael J. Fox Foundation (MJFF): Tell us about yourself. How’d you get into environmental research?
Beate Ritz (BR): I’ve always been interested in the environment because those are the risks you can change. Genetics, you can’t do anything about. What happened in your childhood is done. But at a societal level, we can control our environment. And that gives us a great chance for preventing disease and impacting experience of people living with disease.
MJFF: Both environment and genetics play a role in Parkinson’s. What’s the relative contribution of the environment compared to genetics?
BR: We’re trying to figure this out. Right now, we’re working to estimate how much lifetime air pollution exposure contributes to Parkinson’s. Essentially how much Parkinson’s is due to air pollution. These are averages across whole populations.
But it’s not just genes or environment. There are also gene-environment interactions. There are people for whom an environmental risk is much higher because of their genetics. And there are people for whom a genetic risk is much higher because of their environment. You might not get Parkinson’s if you have just the genetic or just the environmental risk factors. But when the two come together, you have a much higher chance of getting Parkinson’s.
MJFF: A lot of our environment — where we live or work, or the quality of the air around us — can feel out of our control.
BR: It can feel this way. But there is a lot you can do to create awareness of the issues and to influence political discussions. I serve as an expert on panels for the U.S. Environmental Protection Agency (EPA). I advocate. I share the data. You can too. Whenever the EPA rules on pesticides or air pollution standards, you can comment. You can encourage them to take Parkinson’s into account in their rulings. You can help them understand why this is important to you and encourage the agencies to help insulate your and other people from these risks.
MJFF: Apart from advocacy, which is so important, what can you do?
BR: I always recommend to people — whether living with Parkinson’s or at risk for the disease: live as healthy as you can. Exercise. Eat an antioxidant, anti-inflammatory diet, like the Mediterranean or MIND diet. Protect yourself from exposures. If you live near a busy road, don’t open your windows. Use air conditioning instead to keep your indoor air as clean as possible. If you live in areas with wildfires, use air purifiers during the fires and stay indoors.
MJFF: You mentioned exercise, which is critical for all of us, Parkinson’s or not. What about outdoor exercise? Could air pollution and other exposures cancel out benefits?
BR: Researchers have looked at this question. They’ve compared indoor to outdoor exercise, and they’ve studied healthy, young athletes to see whether running or biking near busy roadways still brought benefits. Outdoor exercise does increase exposures, especially because you breathe faster and more deeply with activity. But it’s not clear how harmful that increased exposure might be.
Exercise brings a lot of benefits. And outdoor exercise may bring additional benefits — people may exercise longer and with more social interaction.
I’d say try not to run right next to a busy road. At least have some bushes or greenery between you and the cars. That helps capture some of the pollutants. Go earlier in the morning when exposures may be less. Watch air quality and workout indoors if the air is especially bad.
Download a guide on exercise for brain health and Parkinson’s.
MJFF: You also recommended a healthy diet. Along the same lines, could pesticides cancel out benefits of a good diet?
BR: Pesticides do increase the risk of Parkinson’s, speed progression and contribute to cognitive changes or depression in people with Parkinson’s. To limit pesticides, eat organic fruits and veggies where you can. Don’t live near a golf course, if possible. Don’t use pesticides in your yard or garden. Pay to have the weeds pulled for you, if possible. Or, better yet, pull the weeds yourself for exercise.
Get information on diet for brain health and Parkinson’s.
Read about MJFF and advocate efforts to ban the harmful herbicide paraquat.
MJFF: Water is a key component of a healthy diet. But could water contain harmful substances?
BR: It depends on where you live and your water system. What I worry about most in water are trichloroethylene (TCE) and heavy metals, like lead. Your water should have no or low amounts of these. You can check what’s in your water online, through the city website or where you pay your water bill. You can also have your water tested. And you can filter tap water with an activated carbon or reverse osmosis filter.
One thing to note is that TCE can vaporize or get in the air. This can happen when you take a shower or bath, or even from contaminated groundwater seeping into buildings. That means you breathe it in, too. If there are high TCE levels, you’d have to get a system that filters TCE out of all the water in your home and advocate for cleaner water, in general.
Read about MJFF and advocate efforts to ban TCE.
MJFF: You mentioned lead. Outside of water, where might we be exposed?
BR: People with the highest lead exposure work in occupations like construction, paint removal or the auto industry. As a population, our highest exposure was from lead-based gasoline. Lead was removed from gas 30 plus years ago, but it’s still in “road dust.” When cars drive over this, it gets kicked back up into the air. So those near busy roadways may have higher exposure.
Another place is near small, private airports. Engines in small airplanes — not the commercial ones most of us fly on — use lead-based fuel. So regularly flying or working on these planes or living near a small airport can increase lead exposure.
MJFF: It seems like the main thing we can do is learn about our personal environment and take charge of the main exposures.
BR: That’s true. You can’t avoid every exposure. You might live or work near a place where there is contamination. Look at your heaviest exposures and try to curb those. Outside of that, the best you can do, no matter what the exposure, is live as healthily as you can to limit the impact of toxins.
MJFF: Does that advice — to live as well as we can — differ whether we live with risk, like aging, or we have a diagnosis of Parkinson’s?
BR: Research shows that, in people who have Parkinson’s, environmental exposures can influence the rate of progression and even whether you develop other non-motor symptoms, like depression or cognitive changes.
But the advice is the same for people with disease and at risk: Stay as active as you can, eat as healthy as you can. A lot of environmental factors contribute to disease through a process called oxidative stress. Antioxidants, like you get in a good diet, can fight that stress.
MJFF: As an environmental expert, what gives you most concern?
BR: What keeps me up at night is that toxic agents are constantly replaced by newer agents that we don’t know much about. Will we have to wait several decades to see how toxic they are? We’ve been bringing down air pollution levels substantially, which is great. But there are still sources, namely car exhaust. We’re taking positive steps with electric engines. But brakes and tire wear still bring harmful exposures including toxic metals. We need better public and private transportation concepts and, in general, fewer cars.
MJFF: And what gives you most hope?
BR: I have the most hope that, most immediately, we can get rid of some of the bad actor pesticides. And that what we’ve already learned can help our work toward prevention of Parkinson’s.
Watch a webinar on environment and Parkinson’s, featuring Dr. Ritz and other experts.
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