Hearing Aids May Hold Key to Slowing Cognitive Decline in High-Risk Adults!
Recent research has provided valuable insights into an intriguing concept: addressing hearing loss directly may present an extraordinary approach to reducing the likelihood of cognitive decline and the development of dementia.
Dementia and hearing loss are commonly observed conditions that frequently affect older adults. This study aims to investigate the potential relationship between the use of hearing aids and the risk of developing all-cause and cause-specific dementia in middle-aged and older adults. This study was published in the Lancet on May 2023.
Emerging research indicates that addressing hearing loss may present a promising strategy for reducing the likelihood of experiencing cognitive decline and developing dementia. Hearing loss greatly influences an individual's well-being, affecting physical, cognitive, and emotional health. With an estimated 48 million Americans and over 1.5 billion individuals worldwide affected by various degrees of hearing loss, addressing this issue could serve as a crucial preventive measure in the global battle against the dementia epidemic.
The global prevalence of dementia currently stands at 50 million individuals, and projections indicate that this figure will triple by the year 2050. While there is a known association between hearing loss and cognitive decline, the precise underlying mechanisms remain incompletely understood. Because hearing loss is the most major modifiable risk factor related to the development of dementia, a study into the influence of hearing aids on cognitive function was critical. The study revealed that using devices and audiological support services did not yield any discernible effects on cognitive decline over three years among a diverse group of older adults in the general population.
Recent research has revealed that addressing hearing loss can positively impact cognitive decline, which encompasses the deterioration of memory and cognitive abilities, particularly in older individuals who face a higher risk of developing dementia.
The relationship between the treatment of hearing loss using hearing aids or cochlear implants and the potential impact on cognitive decline or dementia was the subject of a comprehensive review published. This review encompassed 25 observational studies and six clinical trials, providing valuable insights into this important area of research. Individuals with hearing loss who utilized hearing aids experienced a notable reduction in the risk of cognitive decline and dementia.
The review encompassed a meta-analysis of eight cohort studies involving a substantial participant pool of 126,903 individuals, with a follow-up period ranging from 2 to 25 years. The findings revealed that those who addressed their hearing loss through the use of hearing aids exhibited a 19% lower risk of cognitive decline and a 17% lower risk of developing dementia in comparison to individuals who did not correct their hearing loss. This finding was observed in individuals with hearing loss who did not utilize hearing aids compared to those who did. In the context of short-term studies, it was observed that individuals who utilized hearing aids experienced a modest improvement in their cognitive abilities. Unfortunately, the authors encountered a lack of long-term studies investigating the potential correlation between cochlear implants and the likelihood of developing dementia later in life.
According to Professor Frank Lin, a faculty member at Johns Hopkins University School of Medicine and Bloomberg School of Public Health in the United States, the findings of this study present strong evidence supporting the notion that addressing hearing loss can be an effective strategy for safeguarding cognitive function in older individuals. Furthermore, it is plausible that such interventions may even contribute to delaying the onset of dementia in the long run. However, it is important to note that the cognitive benefits of addressing age-related hearing loss are expected to differ based on an individual's specific risk of cognitive decline.
Age-related hearing loss is a prevalent condition that impacts a significant portion of the adult population worldwide, specifically affecting approximately two-thirds of individuals aged 60 and above.
However, the use of hearing aids remains low among individuals with hearing loss in low and middle-income countries, with less than 10% of the population utilizing them. Similarly, the usage rate in high-income countries is even lower, with fewer than three in 10 individuals utilizing hearing aids.
According to the 2020 Lancet Commission on Dementia, it has been observed that untreated hearing loss is linked to a more significant decline in cognitive function. This study estimated that approximately 8% of dementia cases globally, equivalent to 800,000 out of the nearly 10 million new cases diagnosed annually, can be attributed to untreated hearing loss.
There are several hypotheses proposed by experts regarding the potential correlation between untreated hearing loss and cognitive decline as well as dementia.
Hearing loss can exert additional cognitive demands on the brain, adversely affecting various mental functions such as cognitive processing, thinking, and memory.
There are two additional potential explanations to consider. Firstly, it is plausible that hearing loss accelerates the rate at which the aging brain undergoes shrinkage. Secondly, hearing loss may contribute to reduced social engagement, resulting in decreased cognitive stimulation and subsequent brain atrophy.
The Achieve trial, published in The Lancet, involved a sample of 977 adults between the ages of 70 and 84 with untreated hearing loss. These individuals were carefully selected to ensure they did not have significant cognitive impairments. The trial was conducted in four different communities across the United States.
The study included two distinct populations: older adults participating in a well-established observational study known as the ARIC study and were at a higher risk of experiencing cognitive decline, as well as a separate group of healthy volunteers.
The participants were divided into two groups, each receiving a specific intervention. One group received a hearing intervention, which included audiological counseling and the use of hearing aids. The other group received more generalized counseling focused on promoting healthy aging. The participants were then monitored and assessed twice a year for three years.
On average, individuals from the ARIC cohort exhibited certain demographic and health characteristics that differed from those of the volunteer group. Specifically, they tended to be older, predominantly female, possessed a higher number of risk factors associated with cognitive decline, and displayed lower cognition scores at the commencement of the study.
Both groups exhibited comparable hearing levels at the commencement of the study.
The study concluded that the hearing intervention did not reduce cognitive decline over time. There was no statistically significant disparity in cognitive changes observed between the group that received the hearing intervention and the group that received health education over three years.
In the ARIC group, the study observed a significant decrease of 48% in cognitive change over three years among participants who were provided with hearing aids compared to the other group.
According to Professor Lin, it is probable that individuals in the healthier group experienced a slower rate of cognitive decline compared to the participants in the ARIC study. This difference can be attributed to several factors, including the younger age of the healthier cohort, their lower risk factors for cognitive decline, and their superior initial cognitive scores. The relatively short three-year follow-up may have limited the potential impact of hearing aids in further mitigating the decline in cognitive function, which occurred at a noticeably slower rate.
According to Dr. Charles Marshall, a clinical senior lecturer at Queen Mary University of London, the findings indicate a potential advantage of using hearing aids in mitigating cognitive decline among individuals with hearing loss who are otherwise in good health. However, it is important to note that these findings do not definitively establish whether hearing aids can prevent dementia or enhance individuals' cognitive performance during testing.
Hearing loss is often misdiagnosed and undertreated. Hearing aid usage requires not just knowledge of hearing loss and access to technology; hearing aid use may be stigmatizing and unattractive.
There is evidence that hearing aids can be a powerful tool for reducing the risk of dementia in people with hearing loss is as strong as it can be without randomized controlled trials, which may not be practical or ethical because people with hearing loss should not be denied effective treatments. Dementia is not just a disease that affects the person and their family but may also be costly. Hearing aids, on the other hand, are cost-effective and cost-saving in preventing dementia. Hearing aids are now available for purchase over the counter in the United States, making them more accessible.
The research suggests that addressing hearing loss is a potential method of lowering dementia risk. This is the moment to raise hearing loss awareness and detection, as well as the acceptance and usage of hearing aids.