CBS NEWS July 20, 2017

One-third of cases of dementia worldwide could potentially be prevented through better management of lifestyle factors such as smoking, hypertension, depression, and hearing loss over the course of a lifetime, according to a new report.

Across the globe, about 47 million people were living with Alzheimer's and other forms of dementia in 2015. That number is projected to triple by the year 2050 as the population ages. Health care costs associated with dementia are enormous, with an estimated $818 billion price tag in 2015.

The new study, published in The Lancet and conducted by the first Lancet Commission on Dementia Prevention and Care, brought together 24 international experts to review existing dementia research and provide recommendations for treating and preventing the devastating condition.

"Dementia is the greatest global challenge for health and social care in the 21st century," lead study author Professor Gill Livingston, of University College London, told CBS News. "The purpose of the commission was therefore to address it by consolidating the huge strides and emerging knowledge as to what we should do to prevent dementia and intervene and care for people with dementia."

There is currently no drug treatment to prevent or cure dementia. But the report highlights the impact of non-drug interventions and identifies nine modifiable risk factors through various stages of life — beginning in childhood — that affect the likelihood of developing dementia.

 To reduce the risk, factors that make a difference include getting an education (staying in school until over the age of 15); reducing high blood pressure, obesity and diabetes; treating hearing loss in mid-life; not smoking; getting physical exercise; and reducing depression and social isolation later in life. About 35 percent of dementia cases are attributable to these factors, the analysis found. Removing them could then theoretically prevent 1 in 3 cases.

In contrast, finding a way to target the major genetic risk factor, a gene called the apolipoprotein E (ApoE) ε4 allele, would prevent less than 1 in 10 cases – or about 7 percent.

"There's been a great deal of focus on developing medicines to prevent dementia, including Alzheimer's disease," commission member Lon Schneider, M.D., a professor of psychiatry and the behavioral sciences at the Keck School of Medicine of USC, said in a statement. "But we can't lose sight of the real major advances we've already made in treating dementia, including preventive approaches." Schneider presented the findings at the Alzheimer's Association International Conference (AAIC) 2017.

Of the nine risk factors, the researchers identified the three most common ones that could be targeted for dementia prevention.

The first is increasing education in early life, which the report estimated could reduce the total number of dementia cases by 8 percent if all people worldwide continued their education until over the age of 15.

The researchers note that not completing secondary education could raise dementia risk by reducing what's referred to as "cognitive reserve." It's believed that education and other mentally stimulating tasks help the brain strengthen its networks so it can continue to function at a higher level even if it starts to decline later in life.

For the first time, the researchers also identified hearing loss as a major modifiable risk factor for dementia. They estimated that reducing hearing loss in mid-life could also reduce the number of dementia cases by 9 percent if all people were treated.

 What's behind Americans' hearing loss? Livingston notes that research surrounding hearing loss and dementia is still in early stages and the link likely has something to do with the social isolation that can come with losing the ability to hear.

"They may work in similar ways as they reduce the chance of interactions and conversations, which are like exercise for the brain and enrich it and predispose to depression," she said.

Phonak Hearing Aid Accessories
Hearing Loss is independently associated with accelerated cognitive decline. Restated...cognitive function declines more rapidly in a person with untreated hearing loss than in a person with good hearing or a hearing impaired person who is 'corrected' with hearing aids. 
Additionally we know that auditory deprivation (hearing loss) can cause changes in the brain over time...the auditory areas of the brain that are deprived of 'sound' can be recruited for other purposes. 

A 25 year study, reported in the Journal of the American Geriatrics Society (October 2015), compared the cognitive decline in older adults with normal hearing to older adults who were using hearing aids and found no difference in the rates of cognitive decline with age.

Implication: Treat hearing loss early (with hearing aids) to avoid unnecessary complications.

New Research

Topic: Tinnitus

Scientists are close to identifying the molecular cause of  tinnitus...the ringing or buzzing sounds that are the most frequent side effect of hearing loss. Tinnitus affects one in ten people! 

Researchers at the Karolinska Institute have identified a neurotransmitter (glutamate) associated with tinnitus and are working on ways to remove excess levels of this compound. Abnormal glutamate transporters are also associated with seizures and ALS (Lou Gehrig's disease). More accurate standardization of diagnosis and treatment in combination human genetic studies may lead to effective drug therapy for tinnitus sufferers.
Hearing Loss & Dementia  

"Adults with moderate hearing loss are 3 times more likely to develop dementia.

"By 2025, the number of adults aged 65 and older with Alzheimer's disease or a related dementia is expected to increase by 40%.'

A 25 year study, reported in the Journal of the American Geriatrics Society (October 2015), compared the cognitive decline in older adults with normal hearing to older hearing impaired adults who were using hearing aids and found no difference in the rates of cognitive decline with age.
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More New Research

Topic: Understanding Speech in NoiseUnderstanding speech in noise is the "olympic event" for hearing and is most often cited as the biggest problem facing patients with hearing loss. 
A study conducted at the Massachusetts Eye and Ear Institute  have discribed hearing in noise as the "hidden hearing loss". They studied subjects with normal hearing for quiet tones and put them into 2 groups: subjects who wore hearing protection during loud sound exposures and subjects with loud sound or noise exposure on a regular basis (who didn't use hearing protection). Loud sound or noise exposure can damage the sensory connections in the organ of hearing and auditory nerve (auditory synaptopathy) and results in poor understanding of speech when there is noise even... when the subject's hearing for quiet tones is not affected! 
Topic: Fatigue. Can better hearing help beat fatigue. The answer is a clear yes! Hearing loss does play a role and the fatigue is caused by "cognitive load". Struggling to hear in everday listening situations can be very tiresome. The additional effort required to hear conversation puts stress and anxiety on the listener...and can make you feel extremely fatigued by the end of the day.

This topic is also discussed at the bottom of the Phonak Hearing Aid page in an article that discusses Listening Effort and the benefits of Narrow Directionality (Note Phonak and Unitron utilize this technology).
Heart Healthy Life: Heart Disease is the number one cause of death in America. It is estimated that 80 million people have some form of cardiovascular disease The good news is that it is never too late to make lifestyle changes that will lower your risk for heart disease. Include hearing exams as part of your routine physical exams. Studies show that a healthy cardiovascular system has a positive effect on your hearing!

Help prevent dementia by treating hearing loss

Just last week, a study published by The Lancet Commission on Dementia Prevention and Care called dementia “the greatest global challenge for health and social care in the 21st century.” The commission noted that 50 million people have dementia worldwide — and the number is expected to triple by 2050.

The commission identified nine modifiable risk factors that could “reduce the incidence of dementia or substantially delay its onset.” One of these factors is treating hearing loss in mid-life.

This study reinforces what we’ve known for a long time; Hearing better means living better!

Hearing loss is not just an ailment of old age. It can strike at any time and at any age…even childhood. For a child, even mild or moderate hearing loss can cause speech and language problems, learning problems, and can lead to social and psychological problems. (continued below).

Many adults are aware that their hearing has deteriorated, but they are reluctant to seek help. Unfortunately, too many adults wait years, even decades, to address their hearing loss before getting treatment. This is unfortunate because mild to moderate hearing loss is easily treated, and the longer the patient deprives themselves auditorally, the more difficult it is to treat. 

  • Irritability 
  • Negativism 
  • Anger
  • Fatigue 
  • Tension 
  • Stress 
  • Depression 
  • Avoidance or withdrawal from social situations 
  • Social rejection and loneliness 
  • Reduced alertness and increased risk to personal safety 
  • Impaired memory and ability to learn new tasks 
  • Reduced job performance and earning power 
  • Reduced psychological and overall health 


  • Three in ten people over the age of sixty have hearing loss. 
  • One in six baby boomers, ages 49-59, have hearing problems. 
  • One in fourteen young adults, ages 29-40, have hearing loss. 
  • At least 1.4 million children, 18 years or younger, have hearing problems. 
  • It is estimated that 3 in 1,000 infants are born with serious hearing loss. 
  • Hearing loss is very common. Approximately 48 million Americans report some degree of hearing loss. 
  • By age 65, about 1 in 3 adults are affected by hearing loss. 
  •  Tinnitus, a ringing or buzzing sound that can be constant or intermittent; tinnitus is one of the most common side effects of damage to the inner ear.


MYTH: Hearing loss “affects only old people,” and is merely a sign of aging. Actually, the prevalence of hearing loss is the reverse of what most people think. The majority of people with hearing loss (65%) are younger than the age of 65. There are more than 6 million people in the United States alone between the ages of 18 and 44 with hearing loss, and nearly one and a half million of those people are still in school.
MYTH: If I had a hearing loss, my family doctor would have told me. Although 13% of primary care physicians routinely screen for hearing loss, most people with hearing loss hear relatively well in a quiet doctor’s office. Therefore, it can be virtually impossible for your physician to recognize the extent of your problem. Accurate hearing evaluation really requires the expertise of an audiologist.


With recent advancements, it is now possible to perform comprehensive hearing testing to determine:
  • If hearing loss exists, even for our youngest patients. 
  • The amount and nature of the hearing loss. 
  • The benefits that are possible through treatment. 
Breakthroughs in identification in audiologic identification techniques include:
  • Testing the hearing of babies within the first 48 hours of life; now required in most states. Testing can identify hearing loss in children so that a follow-up evaluation and treatment can be performed as soon as possible. 
  • Auditory Brainstem Response (ABR) Testing: This assessment technique can be used with difficult-to-test populations and for medical diagnosis of auditory disorders. The ABR test can be performed on individuals of any age, even the youngest infant. 
  • Immittance testing performs objective and comprehensive evaluation of middle ear function. 
  • Otoacoustic Emissions testing can provide information regarding the health status of the inner ear. 
  • Other specialized tests can identify the exact location of the auditory impairment. 


Noise is one of the most common causes of hearing loss and one of the most common occupational illnesses in the United States. A single shot from a shotgun or rifle, at close range, may permanently damage your hearing in an instant. Repeated exposures to loud machinery over an extended period of time can present serious risks to hearing.
  • Ten million Americans have already suffered irreversible damage from loud noise.
  • Thirty million Americans are exposed to hazardous noise every day. 
  • The risk and harmful effects on hearing are often under-estimated because the damage takes place so gradually. 


  • Consult with an audiologist at the first signs of hearing loss. Remember: ringing or buzzing in the ears (tinnitus) is one of the most common indicators of damage to the ears.
  • Be aware of recreational sources of hazardous noise like firearms, fire crackers, power tools, music concerts, sporting events, motorcycles, motorboats, snowmobiles, and power boats. We have even seen significant hearing loss and significant tinnitus caused by something as “benign” as a parade when fire engines go by with their sirens wailing. Do not be embarrassed to plug your ears with your fingers when there is unexpected noise. Please purchase soft foam earplugs or ear muffs for any planned event or activity where there is going to be excessive sound or noise. Please also remember that, while it is easy for an adult to plug their ears, children will also be at great risk if they are exposed to loud sounds. It is of course the parents’ responsibility to avoid these situations and protect their children


According to the National Institute on Deafness and other Communication Disorders (NIDCD), 36 million Americans have hearing loss… This includes 17% of our adult population. The incidence of hearing loss increases with age. Approximately 1/3 of Americans between the age of 65 and 74, and nearly half of those over age 75, have hearing loss. Hearing loss is the third most chronic health condition facing older adults. Unfortunately, only 20% of those individuals who might benefit from treatment actually seek help. Most tend to delay treatment until they cannot communicate even in the best listening situations. On average, hearing aid users wait over ten years after their initial diagnosis to be fit with their first set of hearing aids.  


Hearing loss in an adult has a number of contributing factors... including age, genetics, noise exposure and chronic disease (eg, diabetes, chronic kidney disease, and heart disease). Age related hearing loss, or presbycusis, is generally a slow progressive hearing loss that affects both ears equally. Presbycusis begins in the high frequencies and later affects the mid and lower frequencies. One of the first signs of hearing loss is often the inability to hear and understand speech in noisy environments. Because of this slow progression, adults with presbycusis do not readily acknowledge their hearing loss, considering it to be a normal condition of aging. As audiologists, we are not surprised to hear that the spouse or significant other has been frustrated by the hearing loss long before the individual with the hearing loss even acknowledges it. It is this insidious nature of presbycusis that allows many adults to ignore their hearing loss for years or even decades. 


Several studies have documented the impact of untreated hearing loss. An often cited survey was commissioned by the National Council on Aging in 1999. This national survey of nearly 4,000 adults with hearing loss and their significant others, showed significantly higher rates of depression, anxiety and other psycho-social disorders in individuals with hearing loss who are not wearing hearing aids. This survey looked at the positive benefits of amplification (hearing aids), and showed that hearing aid use positively affected the quality of life for both the hearing aid wearer and his/her family. These findings were consistent with the findings of a large randomized and controlled study that determined that hearing loss was associated with decreased psycho-emotional well-being, decreased social/emotional well-being, decreased communication and decreased cognitive function, in addition to increased depression for subjects who do not use hearing aids (as compared to those who had received hearing aids). These conditions were all improved after hearing aids were fitted. More recently, Dr. Frank Lin and his colleagues at Johns-Hopkins University found a strong link between the degree of hearing loss and the risk for developing dementia. Individuals with mild hearing loss were twice as likely to develop dementia as those with normal hearing; those with moderate hearing loss were three times more likely; and those with severe hearing loss had five times the risk. While this study could not definitively conclude that early treatment with hearing aids would reduce the risk of dementia, there was a strong positive correlation between the degree of hearing loss and the risk of dementia (Lin 2011).

Regeneration of 'hair cells' (sensory cells) in the inner ear is something that human babies and mice can only do for a short period after birth. Dr. Ksenia Gnedea and her colleagues at the A. James Hudspeth's Laboratory of Sensory Neurosciences have made some progress in activating sensory regeneration of these hair cells in mature mice. (Proceedings of the National Academy of Sciences. Oct. 2015).

Scientists at the National institue on Deafness and other Communication Disorders have recently had success in treating mice with defective inner ears with gene therapy. A particular mutated gene (whirlin) can cause defects in the inner ears of humans and mice. Although not effective in mature mice, newborn mice with the the defective whirlin gene developed normal inner ear stereocilia (hair cells) when injected with the normal whirlin gene. (Molecular Therapy. October 2015)

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