By Dr. Mercola
Approximately 20 percent of Americans, or 48 million people, report they experience some form of hearing loss.1 That percentage rises to nearly 33 percent among those over the age of 65. Unfortunately, hearing loss can have significant repercussions.
According to the Hearing Loss Association of America (HLAA), as hearing loss increases, so does a reduction in compensation in the workplace.2 Men experience hearing loss almost twice as much as women between the ages of 20 and 69.3
While noise is the leading reason for hearing loss, most people will wait up to seven years before seeking help.4 Hearing is integral to much of what you do each day. You rely on your hearing to communicate with people, interact with your environment and appreciate your relationship with the world around you.
Loss of this ability has a significant impact on mental and emotional health, as well as changing how you interact on a daily basis. Recent research suggests exercise may help preserve your hearing, or reduce hearing loss as you age.
How You Hear
How you hear is a unique integration of a complex system that starts with sound waves and ends in your brain. When you know how your body translates sound waves into words and recognizable noise, you have a better understanding of how to protect your hearing.
It all starts with the way your ears are shaped and molded on the outside of your head and ends with nerve endings that travel to your brain. This short video explains how hearing loss may develop.
When a sound is made, it creates waves in the air that are captured by your outer ear and funneled through your ear canal.5 The shape of your outer ear increases the amount of sound that then reaches your eardrum located at the end of your outer ear canal.
These waves cause the eardrum to vibrate, which stimulates three small bones in the inner ear into motion.6 The vibration of these three small bones, the largest of which is a mere 8 millimeters (0.3 inches) long, then reaches the tiny hairs in the cochlea.
This structure looks like a miniature snail shell and is filled with 25,000 tiny hairs along the surface that turn the vibrations into electrical impulses or signals.7 These signals travel along the auditory nerve to your brain, where it is interpreted and given meaning.
As there are several structures involved with hearing, there are also four different types of hearing loss you may experience.
In sensorineural hearing loss, the root problem exists within the cochlea and other surrounding structures. Many people who have this type of loss will say they hear sound, but their brain doesn't interpret it correctly and they don't understand what they're hearing.8
Conductive hearing loss is associated with problems related to the outer or middle ear. Mixed hearing loss is a mix of conductive and sensorineural loss. In some cases, individuals lose hearing in just one ear.
This is called single-sided deafness. The type of loss will determine the treatment options available, from hearing aids to cochlear implants or medication.
Research Links Exercise to Reduced Hearing Loss
The benefits of exercise range from weight loss, improved bone density and cardiovascular fitness to supporting your immune system.9 Now research has linked aerobic exercise with a reduced potential for developing hearing loss as you age.10
Using mice, researchers demonstrated sedentary mice lost important auditory structures, namely hair cells and strial capillaries, in the cochlea.11
Mice who exercised experienced a 5 percent hearing loss in their lifetime while sedentary mice suffered a 20 percent hearing loss on average. Researchers estimate that 70 percent of hearing loss in people over 70 is related to the loss of these structures.
Your hair cells sense sound waves and strial capillaries deliver essential oxygen to your auditory system. Also affected by age-related hearing loss are the spiral ganglion in your cochlear system, responsible for sending sound from the cochlea to your brain.
Your auditory system never stops working and doesn't shut down. This requires a high level of energy, which in turn requires a constant supply of oxygen and nutrients. Damage to the strial capillaries can trigger long-term damage to the cochlea, and therefore hearing loss.
Researchers separated mice into two groups and tracked their behavior and exercise over their lifetime. Mice who were given an exercise wheel ran for an average of 7.6 miles per day at 6 months of age and averaged 2.5 miles each day by their second birthday.
These mice were compared against the second group who did not have access to an exercise wheel and were sedentary. The researchers found exercise appeared to reduce the effect of age-related inflammation and hearing loss in the mice.
They postulate exercise in humans may help to reduce damage to the auditory structures with advancing age as well. Co-author Christiaan Leeuwenburgh, Ph.D., professor and vice chair of research for the Institute on Aging, commented:12
"Exercise likely releases some growth factors yet to be discovered that maintain capillary density as compared to the control animals who were not exercising. Also, exercise may release other beneficial factors, but can also attenuate and blunt negative factors, such as inflammation."
Hearing Loss Linked to Other Health Conditions
Hearing loss has a significant impact on the lives of sufferers. In addition to reducing their income potential, individuals who experience hearing loss are also at a greater risk for depression.13
A study conducted by the National Council on Aging (NCOA) found those with untreated hearing loss were more likely to report being depressed, anxious or paranoid. Researchers also found people who did not treat their hearing loss were less likely to participate in organized social activities. Social rejection, loneliness and avoidance or withdrawal from organized social situations increases the risk for depression.
Loss of hearing also reduces the ability to be alert to environmental cues that may signal dangerous situations, thereby increasing the risk of an accident.14 Hearing loss is an invisible handicap that is often ignored, and may even mask an increased risk of dementia. A strong link was found between the degree of hearing loss and the risk of dementia by researchers from Johns Hopkins University.15
Although researchers did not definitively link early treatment with hearing aids to a reduced risk of dementia, there was a correlation between the risk of dementia and the severity of hearing loss. Researchers have also identified hearing loss as a factor in a reduced quality of life perception in the elderly.16 The combination of poor quality of life and hearing loss may complicate the diagnosis and prognosis of individuals suffering from dementia.
Benefits of Exercise Beyond Better Hearing
According to the U.S. Centers for Disease Control and Prevention (CDC), only 20 percent of Americans get adequate amounts of exercise.17 While exercise is a noteworthy way of helping to prevent age-related hearing loss, it has many other important benefits to your overall health and wellness as well.
✓ Boosts Your Brain Health
Neuroimaging has demonstrated the value of exercise on improving cognitive functions.18 Aerobic activity reduces age-related loss of brain tissue and improves the functional aspects of higher order thinking.
Individuals who are active are also capable of assigning attention to the environment and process information more quickly than those who are sedentary. They also have a lower risk of dementia.19
✓ Improves Your Mood
Short-term and long-term mood improvements are noted in individuals who routinely exercise, as well as a reduction in anxiety. Exercise is also linked with lower rates of depression, and is recommended as treatment for those suffering from clinical depression.22
✓ Improves Your Skin
Reduction in stress and the production of cortisol from your adrenal glands may also affect your skin. Increased circulation and blood flow from exercise means additional oxygen and nutrients reach your skin. By increasing lean muscle mass under the skin, it appears more taut. You accomplish this best through incorporating resistance training into your schedule.
✓ Slows the Aging Process
Exercise improves your flexibility, your sleep quality and lowers your risk of many chronic diseases. It also induces changes to your mitochondrial enzyme content and activity that increases energy production in the cells and the formation of new mitochondria, which is important to energy at the cellular level.23 These changes significantly slow or reverse several age-associated decline in mitochondrial mass.
✓ Faster Recovery From Chronic Illness
✓ Improves Weight Loss Efforts
One of the benefits of using a consistent high-intensity interval training (HIIT) program is that your body begins to use fat as its primary fuel source. Researchers have also demonstrated that when inactive and healthy people exercise briefly and intensely, it produces an immediate DNA change, some of which promotes fat burning.24
✓ You Can Get Fit in Minutes Each Day
You don't have to be training for the Olympics to reap the benefits of exercise. In fact, research has shown that overweight inactive middle-aged men could improve their level of fitness by working out hard for as little as 12 minutes a week, or four minutes three days a week.25
The researchers compared people who exercised for 16 minutes three times a week against a group who exercised four minutes three times a week. They found marked improvements in both groups. Other research demonstrated improvements in insulin sensitivity with as little as three minutes of HIIT per week. 26
Starting an Exercise Program
Begin with the knowledge that it is better to exercise hard for a short period of time than spend an hour doing cardiovascular work. While your initial motivation to exercise may be related to losing weight, you may find you continue the program to experience the benefits to your physical and mental health.27
To get the most out of any planned workouts, I recommend you participate in a comprehensive program that includes HIIT, strength training, stretching and core work. One of the most important pillars to better health this year is to also stay in motion as much as possible during your day. Walking approximately 10,000 steps is a good daily goal to include as non-exercise movement is essential to good health.
If you have an underlying medical condition or have been sedentary, you may want to see your physician to ensure your heart and body can perform hard exercise in the HIIT program.
Using HIIT Effectively
In this video I demonstrate doing a HIIT program on an elliptical machine The key to using a HIIT program is to raise your heart rate to your anaerobic threshold, or the point at which your body is burning oxygen faster than you can deliver it to the cells. You'll know you've reached this threshold as you get very out of breath and can only hold this pace for a short time.
You can do a HIIT program at home using your own equipment, including a bike, rowing, running or any other aerobic exercise. If you don't have equipment at home to use, you can do this same program outside on your bike, rowing on the lake or running on the road. Here's a summary of the key points:
1. Warm up for three minutes.
2. Exercise as hard and fast as you can for 30 seconds. By the end of this 30-second period, you should reach these markers:
• You will be in oxygen debt, and will have difficulty breathing
• You will begin to sweat profusely. Typically, this occurs in the second or third repetition, unless you don't sweat much normally, which could be an indication of a thyroid issue
• There will be a rise in your body temperature
• You will feel a muscle "burn" as your lactic acid increases
3. Recover for 90 seconds.
4. Repeat the high-intensity exercise and recovery five to seven more times. If you're out of shape, start with just two or three repetitions, and work your way up to eight.
Protect Your Hearing
Exercise may help reduce age-related hearing loss, but there are other preventive measures you can take to protect your hearing as you age.
• Avoid loud noise. Approximately 18 percent of adults with a speech-frequency hearing loss between the ages of 20 and 69 report five or more years of exposure to loud noise at work, as compared to 5.5 percent of adults with hearing loss who report no noise exposure at work.28
Noise-induced hearing loss (NIHL) may be immediate or take a longer time to present symptoms.29 In some cases, loss may be temporary, such as after a loud explosion. However, the damage after one incident may also be permanent.
• Eat a healthy diet. Among the nutrients found to be most beneficial for protecting and improving hearing are carotenoids (astaxanthin and vitamin A),30 folate,31 zinc32 and magnesium.33 These nutrients may support hearing by protecting against oxidative stress in the cochlea, improving blood flow, improving homocysteine metabolism and preventing free radical damage.
• Practice listening skills. Hearing sound and interpreting the meaning in your brain require two different skills. By training your brain to distinguish sound more effectively, you may also help to reduce listening fatigue. Three areas of your brain are connected with your ability to hear and interpret sound. These are Broca's area (producing speech), Wernicke's area (understanding speech) and your temporal lobe that manages hearing.
With hearing loss, your brain has to work harder and concentrate more to achieve the same results you did before hearing loss, which increases the challenges of communication and leads to fatigue.34 Practicing and sharpening your listening and understanding skills may help to reduce this fatigue if you experience mild hearing loss.