Parkinson’s disease is a neurodegenerative disorder that affects millions worldwide. It’s characterized by motor symptoms like tremors and slow movement, but also includes non-motor symptoms such as cognitive decline and, surprisingly, hearing loss.
These non-motor symptoms often appear years before the more recognizable motor issues, making them valuable indicators of risk. A study published in Parkinsonism & Related Disorders, using data from the UK Biobank, revealed a 57% increase in Parkinson’s risk for every 10-decibel increase in baseline hearing impairment.1
This means that even slight difficulties understanding speech amidst other noise could signal a heightened risk for developing Parkinson’s. Previous research also showed that hearing loss doubles or even triples the risk of dementia.2 The “common cause hypothesis” suggests that both hearing loss and dementia arise from the same underlying disease processes.
These shared pathways, including mitochondrial dysfunction and changes in certain proteins, are also implicated in Parkinson’s disease. Therefore, the possibility that hearing loss is an early indicator of Parkinson’s becomes even more compelling.
How Is Hearing Impairment Linked to Parkinson’s Disease Risk?
The Parkinsonism & Related Disorders study investigated the relationship between hearing impairment, measured through a speech-in-noise test, and the development of Parkinson’s.3 The study revealed a strong correlation between poorer hearing and a higher likelihood of being diagnosed with Parkinson’s.
• Extensive data supports the findings — The researchers analyzed data from 159,395 individuals, tracking them over a period exceeding 14 years to see who developed Parkinson’s. One of the key strengths of this study is its large sample size and long follow-up period.
• Hearing loss as an independent risk factor — By adjusting for factors like age, sex and education, the study aimed to isolate the effect of hearing impairment on Parkinson’s risk, strengthening the argument that hearing loss could be an independent risk factor for the disease. This suggests that the connection between hearing and Parkinson’s is not merely coincidental but likely indicative of shared underlying mechanisms.
• Implications for early detection and care — According to study author Megan Readman from Lancaster University’s department of psychology:4
“These findings are incredibly important; first, this is one of the first studies to look at how hearing impairments may increase risk for Parkinson’s or be an early warning sign of Parkinson’s.
Secondly, as our findings suggest, hearing loss is intricately related to Parkinson’s so it may be beneficial for auditory functioning and the management of auditory impairment to be considered at the time of diagnosis and follow-up care.”
To learn more about Parkinson’s origins and its deeper connections to overall health, read “Research Shows Parkinson’s Disease Origins in the Gut.”
Does Parkinson’s Disease Affect Hearing and Auditory Processing?
A 2017 study published in BioMed Research International also explored the impact of Parkinson’s disease on both peripheral and central auditory functions.5 Here, the researchers compared hearing abilities between 35 individuals with Parkinson’s and a control group of 35 healthy adults of a similar age, focusing on how the disease affects not just hearing sensitivity but also the brain’s ability to process sounds.
• Hearing issues in Parkinson’s patients often go unnoticed — The findings of this study are important, as hearing tests are not routinely included in Parkinson’s evaluations,6 and assessments of central auditory processing are not likely to be administered at all. This means many patients experience hearing difficulties without proper diagnosis or intervention.
• Comprehensive hearing assessments — Participants underwent a series of assessments, including questionnaires about their hearing experiences, neuropsychological tests to evaluate cognitive function, standard audiometric testing to measure hearing sensitivity and a battery of tests designed to assess central auditory processing.7
This comprehensive approach allowed the researchers to examine hearing from multiple angles, looking at both the ear’s ability to detect sound and the brain’s ability to interpret it.
• Parkinson’s impacts speech comprehension — Both groups exhibited age-related hearing loss, which is a common finding. However, the Parkinson’s group reported significantly more difficulty hearing words spoken by people, a key aspect of communication.8 This suggests that Parkinson’s might be impacting their ability to understand speech, even beyond what could be explained by typical age-related changes in hearing.
• Central auditory processing difficulties — The study found Parkinson’s patients also struggled with processing sounds, particularly in understanding speech in noisy environments, distinguishing between similar sounds and processing auditory information quickly and accurately.9 These deficits suggest that Parkinson’s affects auditory pathways in the brain, impacting their ability to effectively process and interpret sounds.10
These findings highlight the significant impact of auditory challenges on daily life, making conversations challenging and contributing to social isolation.
What’s the Link Between Hearing Loss, Dementia and Parkinson’s Disease?
In related news, a 2024 study published in Medicina investigated the complex relationships among hearing loss, dementia, Parkinson’s and the APOE genotype, which raises Alzheimer’s disease risk.11 The researchers explored how hearing loss impacts cognitive impairment, Parkinson’s severity and the expression of the APOE gene, which plays a role in neuronal health. This study is unique because it directly compares these three conditions based on APOE gene expression.
• Thorough participant evaluation — The study enrolled 72 outpatients diagnosed with either Parkinson’s or hearing loss. Participants underwent a thorough hearing assessment, cognitive function tests and an evaluation of Parkinson’s severity. Blood samples were also collected to analyze APOE gene expression.
• Hearing loss progresses alongside cognitive and motor decline — Patients with dementia had significantly worse hearing thresholds compared to those without dementia. Similarly, individuals with severe Parkinson’s also exhibited poorer hearing thresholds and a higher prevalence of dementia compared to those with mild Parkinson’s.
• APOE ε4 allele and cognitive decline — The researchers found that individuals carrying the APOE ε4 allele, a specific variant of the gene, had a higher prevalence of dementia. This finding aligns with previous research highlighting the APOE ε4 allele as a risk factor for cognitive decline.12
While the study didn’t find a direct link between the APOE ε4 allele and Parkinson’s severity, its association with dementia suggests a broader impact on neurodegenerative processes.
To learn more about how sensory impairments relate to dementia, read “The Curious Link Between Dementia and Sensory Impairments.”
Five Proactive Strategies to Protect Your Hearing and Brain Health
The research is clear — hearing impairment is linked to an increased risk of Parkinson’s. This connection highlights the importance of taking proactive steps to protect both your hearing and your brain health. Mitochondrial dysfunction, a key driver of neurodegeneration, is a central factor in this relationship.
By focusing on supporting your mitochondria, you improve cellular energy, a cornerstone of chronic disease prevention. Here are five steps to boost your cellular power and protect your long-term health.
1. Eliminate processed foods and vegetable oils — I recommend steering clear of vegetable oils like corn, soybean, safflower and canola. These oils, found widely in processed foods, are high in linoleic acid (LA), which interferes with mitochondrial function, hindering your cells’ ability to produce energy.
Focus on whole foods, like fresh fruits, grass fed butter or tallow, and collagen-rich proteins, instead. When dining out, always ask what oils are used and avoid dishes made with vegetable oils. This dietary shift helps safeguard your mitochondria from accumulating damage, supporting long-term brain health.
2. Make smart carb choices — The right carbohydrates are key for consistent energy, especially for your brain cells. If your gut health is compromised, start with easily digestible options like white rice or whole fruits.
Gradually introduce more fiber-rich carbs as your gut heals. Aim for around 250 grams per day, adjusting as needed to match your activity level. Very active individuals require more carbohydrates to support energy production. This helps prevent mitochondrial stress caused by a low-carb diet.
3. Minimize toxin exposure — Endocrine-disrupting chemicals (EDCs) in plastics, excess estrogen and constant exposure to electromagnetic fields (EMFs) interfere with cellular energy production. These toxins build up over time, reducing mitochondrial efficiency, so it’s important to take steps to limit your exposure.
Consider switching to natural household products, storing food in glass containers and creating an EMF-free sleep environment to allow your cells to rest and recharge overnight. Reducing your overall toxin load lessens the burden on your body and brain.
4. Embrace the sun safely — Regular sun exposure is important for cellular energy production. It stimulates mitochondrial melatonin, a potent antioxidant. However, until you’ve been seed-oil free for at least six months, avoid direct sun exposure during peak hours (10 a.m. to 4 p.m. in most U.S. areas), as the LA stored in your tissues makes you more susceptible to sunburn.
5. Boost NAD+ levels — Supplement with niacinamide (50 milligrams, three times a day) to boost NAD+ levels. NAD+ is important for mitochondrial energy production, healthy cell death signaling and a robust immune response, helping your body identify and eliminate damaged cells.
Frequently Asked Questions (FAQs) About Parkinson’s Disease and Hearing Loss
Q: Is hearing loss an early warning sign of Parkinson’s disease?
A: Yes. Research shows that hearing loss appears years before motor symptoms. A study found that for every 10-decibel increase in hearing impairment, Parkinson’s risk increased by 57%.
Q: How does Parkinson’s affect hearing and speech comprehension?
A: Parkinson’s impairs both hearing sensitivity and the brain’s ability to process sounds. Patients often struggle to understand speech in noisy environments and distinguish between similar sounds, even when standard hearing tests appear normal.
Q: What’s the connection between hearing loss, dementia and Parkinson’s?
A: Hearing loss is a well-known risk factor for dementia. A study also found that individuals with severe Parkinson’s had a higher prevalence of dementia and worse hearing thresholds, suggesting overlapping neurodegenerative mechanisms.
Q: How can I improve my hearing and brain health naturally?
A: Avoid ultraprocessed foods and vegetable oils, eat nutrient-dense carbohydrates, limit toxin exposure, get safe sun exposure and supplement with niacinamide to boost your mitochondrial function and protect against neurodegeneration.
