People who regularly eat ultraprocessed foods could be at a higher risk of developing Parkinson’s disease, a new study has suggested.
The additives in favourites like crisps, biscuits and supermarket, packaged bread can harm the trillions of beneficial bacteria in the gut.
These compromised bugs send signals to the brain that triggers damage seen in the degenerative condition, according to scientists.
Research has long shown that diets high in ultraprocessed food can disrupt the natural balance of bacteria in the gut, triggering inflammation that can trigger a host of health complications—including problems with brain activity.
Now, experts from King’s College London have explored the impact on the risk of Parkinson’s—which causes cognitive decline and mobility problems due to the death of nerve cells in the brain.
The researchers studied 88 participants with Parkinson’s and found they had a less diverse gut microbiome—the community of ‘friendly’ bacteria that live in the gut and communicate with the brain—than the healthy controls.
They also had higher levels of harmful bacteria in the gut, which has been linked to the degenerative disease.
Intriguingly, their experiments also showed that a good and consistent oral hygiene routine could potentially ward off this precursor the disease.
Research has long suggested that activity in the gut can impact the brain. Researchers have now found people with Parkinson’s have more harmful bacteria in the gut which could contribute to cognitive decline
Regularly eating ultraprocessed foods has been previously linked with Parkinson’s with the additives in the foods said to promote inflammation and oxidative stress in the brain
This is because harmful bacteria found in the mouth can migrate to the gut, where they have knock-on effects for the rest of the body, the scientists suggested.
It comes as studies show Parkinson’s is on the rise in the UK.
Currently, around 153,000 people are affected, but experts predict this figure will rise to 172,000 adults by 2030.
The staggering increase is thought to be a result of a combination of factors including environmental toxins and the rapidly aging population.
Writing in the journal Gut Microbes, researchers suggested a significant change in bacteria found in the gut and the mouth may promote inflammation, which damages neurons in the brain that create dopamine, a neurotransmitter that affects movement and mood and is lacking in Parkinson’s sufferers.
The researchers found that patients with mild cognitive impairment had more harmful bacteria in the gut, which could cause damage to dopamine-producing neurons in the brain.
Therefore, the experts suggested that eating a balanced, diverse diet low in ultraprocessed food could slash the risk of developing Parkinson’s and help delay the cognitive symptoms of the condition.
However, Dr Frederick Clasen, co-author of the study, said: ‘We don’t yet know if the bacteria are causing the cognitive decline or if changes in the body due to Parkinson’s allow these bacteria to grow.
Symptoms of Parkinson’s include uncontrollable tremors, slow movements and muscle stiffness. Thinking and memory changes including becoming more forgetful can also occur
Researchers said that a consistent oral hygiene routine could help ward off cognitive decline, with common gum diseases having been flagged as a potential driver of Alzheimer’s
‘But our findings suggests they [harmful bacteria] may play an active role in worsening symptoms’.
There are around 18,000 new diagnoses of Parkinson’s every year in the UK, mostly in people 45 and older.
Parkinson’s disease is a progressive movement disorder in which the brain cannot produce enough dopamine, a neurotransmitter that controls movement.
A lack of dopamine leads to issues like tremors and falls, and can contribute to cognitive changes.
In the study, saliva and stool samples were taken from two groups of Parkinson’s patients—41 showed signs of mild cognitive impairment and 47 suffered significant cognitive symptoms, akin to dementia.
There were also 26 healthy control participants with no Parkinson’s diagnosis.
The authors found a reduction in levels of three beneficial bacteria in Parkinson’s patients, including two that are known to be protective against dementia.
Researchers added that low levels of bacteroides uniformis—another type of bacteria associated with Parkinson’s and dementia—could be an indication of too little dopamine.
Actor Michael J Fox (pictured here) was diagnosed with Parkinson’s disease at just 29 years old. He now advocates for more research into the condition
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They also found that the migration of bacteria that is usually found in the mouth to the gut could be a risk factor for Parkinson’s.
However, researchers acknowledged that they failed to consider other lifestyle factors—such as diet, stress, sleep, and exercise—that are known to impact the gut microbiome.
According to the Parkinson’s Foundation, digestive issues are one of the most common symptoms in Parkinson’s, with constipation affecting up to 70 per cent of those diagnosed.
This symptom often begins before the onset of tell-tale movement delays and other early signs of the disease.
While research on Parkinson’s and the gut is in its infancy, it has long been suggested that activity in the gut influences the brain.
‘These toxins could be used as biological markers to identify patients at higher risk of Parkinson’s,’ explained Frederick Clasen, microbiome researcher and co-author of the study at King’s College London.
‘In the future, they might also be targets for new treatments that protect the brain by changing the gut environment,’ he added.
The findings come as Chinese scientists discovered those who regularly eat ultraprocessed foods have nearly triple the risk of developing Parkinson’s.
They found people who ate 11 or more servings of ultraprocessed foods a day—such as sugary condiments, sweets, and processed meat—were 2.5 times more likely to show early signs of the degenerative disease.
The researchers believe additives in ultraprocessed foods like emulsifiers and sweeteners may trigger chemical reactions that damage dopamine-creating neurons in the brain.