Carly Simon has largely stayed out of the public eye in recent years, and on Monday, she revealed why.
The You’re So Vain singer, 83, announced that she was diagnosed with Parkinson’s disease, and has been taking time to learn ‘how to live’ with the neurological disorder.
In a statement to People magazine, Simon also offered a message of hope: ‘I have not stopped living, and I have not stopped working.’
Her diagnosis shines a spotlight on Parkinson’s, a devastating disease that occurs when nerve cells in the brain that produce dopamine, the chemical that helps control movement, gradually die, leading to tremors, stiffness, balance problems and speech difficulties that worsen over time.
Around 90,000 Americans are now diagnosed each year, about 50 percent more than in the early 2000s, and an estimated 1.2 million people are expected to be living with the condition by 2030.
And Simon joins a number of celebrities to have also developed the disease, among them musician Neil Diamond, who was diagnosed with Parkinson’s in 2018, and actor Michael J Fox, who was diagnosed in 1991 at the age of 29.
While an ageing population explains some of the increase, scientists are also investigating whether factors including pesticides, smoking, head injuries and contact sports could be contributing to the rise.
So what is really driving America’s Parkinson’s epidemic?
Carly Simon announced that she was diagnosed with Parkinson’s disease
Why aging – and better diagnosis – aren’t the whole story
Parkinson’s disease affects a small area of the brain called the substantia nigra, where most of the dopamine involved in controlling movement is produced.
Dopamine is a chemical messenger that allows nerve cells to communicate, helping the brain coordinate smooth, controlled muscle movements. As we age, it is normal for dopamine-producing cells in the substantia nigra to die, but in most people this happens slowly.
In people with Parkinson’s, however, these cells are lost much more rapidly. Symptoms typically do not appear until around 50 to 60 percent of them have been destroyed.
The biggest single risk factor is age. The likelihood of developing Parkinson’s rises sharply after 50, with most people diagnosed between the ages of 60 and 70. Men are also more likely to develop the condition than women.
Genetics also plays a role. Having a parent or sibling with Parkinson’s increases the risk, and researchers have identified several gene mutations linked to the disease. However, experts estimate that only around ten to 20 percent of cases are primarily genetic, meaning the vast majority are considered idiopathic – with no single identifiable cause.
An ageing population and improved diagnosis can partly explain why Parkinson’s has become more common in recent decades.
But many scientists believe those factors do not fully account for the increase, particularly in younger patients, prompting researchers to investigate whether environmental ‘exposures’ may also be contributing.
As Dr Ted Dawson, director of the Institute for Cell Engineering at Johns Hopkins, puts it: ‘We think it’s probably a combination of environmental exposure – to toxins or pesticides – and your genetic makeup.’
How air pollution is driving the Parkinson’s explosion
Scientists have long known that air pollution damages the lungs and heart. Increasingly, evidence suggests it may also harm the brain.
One of the biggest concerns is fine particulate matter (PM2.5) – microscopic particles around 30 times thinner than a strand of human hair. Produced by vehicle exhausts, industry, wildfires and even wood-burning stoves, these tiny particles can be inhaled deep into the lungs before entering the bloodstream.
Scientists believe they may trigger inflammation throughout the body, including in the brain, damaging dopamine-producing neurons and increasing the risk of Parkinson’s.
Another theory is that pollution first causes inflammation in the gut, where the Parkinson’s-linked protein alpha-synuclein begins to clump before traveling to the brain via the vagus nerve.
‘There are theories that Parkinson’s can start either from the airways, from your nose, and then whatever you inhale can affect the brain,’ Mosier said.
Smoking rates in America have plummeted over the past 60 years. Just 11.6 percent of US adults now smoke, down from 43 percent in 1965, as overwhelming evidence has shown cigarettes cause lung cancer, heart disease and chronic lung conditions such as COPD.
Yet Parkinson’s researchers have long been puzzled by an unexpected finding: smokers consistently appear less likely to develop the disease.
Scientists are still trying to understand why.
One theory is that nicotine helps stimulate dopamine release and protects dopamine-producing neurons from dying.
Another is that the low levels of carbon monoxide inhaled by smokers may reduce the build-up of alpha-synuclein – the toxic protein that forms clumps in the brains of people with Parkinson’s.
In a 2024 study, researchers at Massachusetts General Hospital found carbon monoxide appeared to limit alpha-synuclein accumulation in laboratory experiments, suggesting it could delay the onset or progression of the disease.
But experts stress this is not a reason to light up.
‘Of course, there are so many negative side effects to smoking, we would never tell people to smoke,’ Mosier said.
The evidence is mounting. In one 2024 study of more than 300 Parkinson’s patients, researchers found those exposed to the highest levels of PM2.5 were 23 percent more likely to develop the disease than those exposed to the lowest levels. They were also 36 percent more likely to develop the akinetic-rigid form of Parkinson’s, which is linked to faster cognitive decline and more severe movement problems.
Separate research from the Barrow Neurological Institute found people living in areas with higher PM2.5 concentrations were 56 percent more likely to develop Parkinson’s.
One of the biggest challenges is that the damage may begin decades before symptoms appear, making it difficult to identify the trigger until long after the exposure has occurred.
Pesticides in food and golf courses raise the risk
Pesticides have long been suspected of playing a role in Parkinson’s disease, and recent research has strengthened that link.
Earlier this year, scientists at UCLA focused on chlorpyrifos – an insecticide used on crops, forests and grassy areas such as golf courses.
After analyzing pesticide exposure in 800 people with Parkinson’s and testing the chemical in zebrafish – which are widely used in medical research because they share around 70 percent of their genes with humans – they found chlorpyrifos was associated with a 2.5-fold increased risk of the disease.
Introduced in 1965, chlorpyrifos was once among the most widely used pesticides in the US. In 2021, the Environmental Protection Agency announced a ban on its use on food after studies linked even low-level exposure to neurological harm.
However, a 2023 court ruling overturned the decision, allowing agricultural use to continue. Several states, including California, Hawaii and New York, have since introduced their own bans, but the chemical can still be used on golf courses.
Musician Neil Diamond was diagnosed with Parkinson’s in 2018. He is pictured in 2022 with wife Katie McNeil Diamond
Michael J Fox was diagnosed with Parkinson’s disease in 1991 at the age of 29. He is pictured with his wife, Tracy Pollan, in June 2026
Another chemical under scrutiny is paraquat, a herbicide that studies suggest can trigger inflammation and damage dopamine-producing neurons. Although banned in around 70 countries, it remains legal in the US as a restricted-use pesticide, meaning only licensed applicators can use it.
‘These are common pesticides used in farming, so not only are the people applying them at high risk, but also the people living nearby – and all of us eating foods treated with these pesticides,’ Mosier said. ‘They’ve really gotten into our whole food supply.’
More than half of food sold in the US contains detectable residues of at least one pesticide.
Blows to the head that leave lasting damage
Boxing legend Muhammad Ali’s Parkinson’s diagnosis in 1984 raised a question that scientists are still trying to answer today: can repeated blows to the head increase the risk of the disease? The boxing legend was just 42 when he was diagnosed and lived with Parkinson’s for more than 30 years.
More recently, former NFL quarterback Brett Favre revealed he had also developed Parkinson’s, saying he believes repeated head trauma during his career may have played a role.
The concern extends beyond professional sport. Mosier also points to military veterans exposed to explosions and repeated impacts.
‘There has been a correlation for a long time,’ she said.
The research is compelling. Scientists at Mass General Brigham estimate former NFL players are around four times more likely to die from Parkinson’s than the general population. Meanwhile, a 2020 study of nearly 50,000 people found that even a single concussion was associated with a 57 percent higher risk of developing the disease, as well as a 72 percent increased risk of dementia.
Researchers believe repeated head injuries encourage the build-up of the protein alpha-synuclein, causing it to misfold and clump together. At the same time, trauma damages the brain’s microglia, cells responsible for clearing away waste, allowing the toxic clumps, known as Lewy bodies, to accumulate and ultimately destroy dopamine-producing neurons.
Head trauma has also been linked to amyotrophic lateral sclerosis, another progressive neurological disease that damages the nerve cells controlling muscle movement.
Former NFL quarterback Brett Favre revealed his Parkinson’s diagnosis in 2024 at the age of 54
Is there anything you can do to prevent it?
While there is no guaranteed way to prevent Parkinson’s disease, experts say several lifestyle changes may help lower the risk or delay its onset.
Chief among them is regular exercise. Mosier, whose organization Power for Parkinson’s provides free exercise classes for people with the disease, says she sees the benefits every day.
‘Exercise has been proven to be medicine for someone with Parkinson’s,’ she said. ‘People are not progressing, and many times I see their symptoms improve.’
Studies back that up: a 2024 Yale University study found high-intensity exercise helped preserve dopamine-producing neurons, while UCLA researchers reported that physical activity triggered DNA changes linked to reduced inflammation in the brain.
Exercise is thought to boost neuroplasticity, the brain’s ability to adapt and form new neural connections, allowing it to compensate for some of the damage caused by Parkinson’s.
Mosier also recommends limiting exposure to pesticides where possible, such as by thoroughly washing fruit and vegetables or choosing organic produce when practical, and protecting the head during contact sports and activities with a high risk of falls.
Finally, she says recognizing the early warning signs can make a difference. Parkinson’s often develops gradually, with symptoms such as a softer voice, smaller handwriting, slower walking, a reduced sense of smell or constipation appearing years before the more familiar tremor.
