What’s Causing the Parkinson’s Belt?

Parkinson’s Disease is about as bad as it gets.

The neurodegenerative disease takes away your control over your own body.

It’s so devastating that one of the only ways it can get worse is by affecting more people.

And unfortunately, that’s happening.

Globally, the number of people with Parkinson’s has more than doubled in 25 years.

And in some locations like the U.S. Midwest, the number is much higher.

For something that tends to be age-related or genetic, that’s weird.

But the scientific community has some pretty solid evidence about what’s different in those places.

So here’s what’s causing a dramatic uptick in Parkinson’s cases, and what we can do about it.

[ INTRO ] In general, as we age, things don’t work as well as they used to.

There are a number of diseases that can come from the gradual loss of function in your brain and body with age, and Parkinson’s is one of them.

So it makes sense that as humans live longer, we see an increase in the rate of diagnosis for those things.

But if the dramatic surge in Parkinson’s could be explained that way, this would be a pretty short video.

Sadly, the number of cases rose far more than it would if the increase were just related to longevity.

And it probably isn’t due to better diagnostics either.

During the time period that Parkinson’s has been on the rise, iagnostics have improved at the same rate for Parkinson’s as for several other neurological disorders like multiple sclerosis, whose rates of diagnosis haven’t increased as much.

And even though some Parkinson’s patients have a family history of the disease, this increase also probably isn’t due to genetics.

Because similar rates have been observed in identical and fraternal twins.

If genetics were to blame, we’d expect to see more diagnoses among identical twins.

And we don’t.

So researchers needed to look for another cause.

And they found it in geography.

Well, the environmental contaminants that dominate certain areas more than others.

Like, you know the stretch of land across the US midwest where so much manufacturing took place that it was later dubbed the “rust belt?” In 2010, researchers observed that this area was abnormally high in Parkinson’s cases.

Up to ten times higher than other parts of the US.

It was so extreme that it got a new name: the Parkinson’s belt.

And they think this geographical anomaly comes from the products of industrialization that are common along that corridor, like air pollution.

There’s an association between more particulate matter in the air and a higher risk of Parkinson’s.

That’s been observed in the US, but also across the world.

A meta-analysis pooled results from countries as far away as Italy and Taiwan, and found that all sorts of air pollutants were linked to Parkinson’s.

Not just particulate matter, but also nitric oxide, carbon monoxide, and ozone.

Each of those air pollutants can damage or destroy dopamine neurons, and those are the main brain cells harmed in Parkinson’s Disease.

So air pollution seems to be tied to Parkinson’s in the Midwest … with a triple knot.

But before I get to the other places this is happening, an ad

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Unfortunately, the Rust Belt isn’t the only place where Parkinson’s is on the rise.

A study in Iowa and North Carolina found a strong connection between Parkinson’s diagnoses and pesticide use.

People in this study who used the common pesticides paraquat and rotenone at least once in their lives were more likely to be Parkinson’s patients than those who never used them.

Now, lots of people use pesticides.

But this factor might go hand in hand with rural areas where there tends to be more of them.

One study looked across France and found the most Parkinson’s cases where the vineyards were.

Probably not coincidentally, vineyards use a ton of pesticides.

In that study, they sampled almost 70,000 people, in a variety of professions and locations.

And the effects weren’t just among farmers, but generally people who lived near vineyards.

They also saw that as the number of goats went up, so did the Parkinson’s cases.

But they really had no idea what that was about.

Sometimes in science, you find valuable new insights into the association between pesticides and Parkinson’s.

And sometimes, there’s random inexplicable goats.

It’s all part of the process.

While they didn’t have an explanation for how goats might influence Parkinson’s development, they had some solid ideas about pesticides.

Paraquat and rotenone are known to inhibit the mitochondria in your cells, and they can lead to oxidative stress.

Both of those things generally raise an alarm that something is going wrong.

They can even cause problems with a gene called alpha synuclein, which usually helps your brain cells use chemicals like dopamine.

So there are a few ways that pesticides could spur on Parkinson’s.

And as bad as paraquat and rotenone are on their own, the effects can get even worse when you’re exposed to multiple toxins.

Just imagine what would happen if you were in a place that used a lot of environmental contaminants and you were next to another place that did the same.

That’s how we learned that you don’t need to live in the rust belt or in a rural area to be at risk.

You could be on a military base next to a dry cleaner.

I’m talking about Marine Corps Base Camp Lejeune in North Carolina.

Listen, the military doesn’t tell us everything they’re up to.

So was the dry cleaner next door really involved in this story at all, or was the underground fuel storage leaking on a base that happened to be next to a dry cleaner?

We have limited intel.

We just know that a chemical called trichloroethylene, or TCE, was found in the water there in the early 1980s.

TCE is in degreasers, dry cleaning solvents, and tons of other stuff … and has been associated with Parkinson’s Disease.

When all of this was going down, the drinking water on the base was tested and it had 70x the maximum amount of TCE that the Environmental Protection Agency is okay with.

So regardless of where it came from, people needed to investigate the health effects of so much contamination.

But TCE isn’t generally the kind of thing that makes a third ear grow on the back of your head the next day.

It takes time for the effects to manifest.

So it wasn’t until 2023 that a study showed some of the results of that contamination.

Researchers compared more than 100,000 people who had been stationed at Camp Lejeune in the 70s and 80s with more than 100,000 people who had been stationed at Camp Pendleton in California during roughly the same period.

And they followed up with them to check on any Parkinson’s status through 2021.

I’m sure you saw this coming, but they found significantly higher rates of Parkinson’s and its precursor symptoms among military members at Camp Lejeune compared to their peers at Camp Pendleton.

This is probably because, at least in rats, TCE kills the brain cells that make dopamine, which are super involved in Parkinson’s disease.

And you know those mitochondria problems related to those other contaminants?

Let's just say that TCE is looking pretty suspicious for that stuff, too.

So whether you’re in the throes of industrialization, tending to your grape vines, or on a toxic military base, you might be in one of the Parkinson’s pockets sprinkled throughout the world.

And since contamination-proof bunkers aren’t practical, let me offer some hope for reversing the rise in Parkinson’s.

A study published in 2016 followed residents of Rotterdam in the Netherlands between 1990 and 2010.

During a time when the Netherlands decreased their toxic chemical use, this study found a significant reduction in new Parkinson’s cases.

This seems like a simple fix.

Don’t spew environmental pollutants into the world, and we can lower our global Parkinson’s rates.

But it’s not as simple as it sounds.

First of all, convincing people not to use cars, pesticides, and other pollutants has proven pretty tough.

And not everyone is completely sold that this finding is air-tight evidence of a solution.

Maybe reducing contamination is a factor in reducing Parkinson’s rates, but not sufficient to solve the problem alone.

Also, the Netherlands study didn’t gather data on pesticide rates or other causes.

They were mostly just looking at Parkinson’s rates in Rotterdam.

So other researchers connected the dots between their findings and the reduction in chemical usage d uring the same period.

All of that’s to say, we don’t have a perfect solution that we know 100% will work.

But even if that data isn’t related to environmental pollutants, we know that Parkinson’s is, so reducing them as a potential solution still stands.

Worst case scenario: we have a cleaner world to live in.