In the United States, age-related hearing loss affects

about a quarter of those in their 60s, more than half of those in their 70s,

and 80 percent of those in their 80s.

More than 95 percent of centenarians have been found to have severe hearing loss.

Because of impaired communication, this may lead to social isolation,

loneliness, and depression.

It may even threaten one's life

due to an associated increase in motor vehicle accidents.

What can we do to prevent age-related hearing loss?

It's said to be a natural part of the aging process,

but that's what we used to think about pathological conditions

like high blood pressure.

The vast majority of people eventually develop hypertension,

just like the vast majority of people eventually lose their hearing;

so, it must just be an inevitable consequence of growing old, right?

But then it was discovered that there were rural populations

living in Africa and Asia that ate and lived healthier,

that didn't experience an inexorable rise in blood pressure as they aged.

So, it appeared hypertension was more a lifestyle choice

than an aging effect—and the same may be true for hearing loss.

The Mabaan tribe living in the Sudanese desert

was found to retain their hearing into old age.

Other studies on isolated native populations

found that exposure to modern civilization

appeared to undercut their hearing advantages.

What is it about our modern world that appears to be leading

to a loss of hearing as we grow older?

Age-related hearing loss is a result of the premature death

of the sensory hair cells in our inner ear

which turn vibrations to electric signals to the brain.

Once they're lost they don't grow back; so, prevention is critical.

The question is: What's killing them?

A study of more than 2,000 twins found that the heritability

of age-related hearing impairment was only 25 percent;

so, most of risk is due to nongenetic influences.

Risk factors include repeated exposure to loud noises, smoking,

and ototoxic (or hearing-damaging) medications.

Noise exposure early in life appears to render the inner ear

more vulnerable to aging.

Animal studies suggest exposure to low level

but constant noise over 60 decibels may also be harmful.

This has not been demonstrated in humans,

but if you use a white noise generator to sleep

it can't hurt to check that it's under 50.

Medications known to be ototoxic include aminoglycoside antibiotics

(like streptomycin, amikacin, neomycin, and kanamycin)

which are among the highest risk medications for hair cell toxicity.

But NSAIDS, anti-inflammatory drugs like aspirin, ibuprofen,

and naproxen, and loop diuretics (for example furosemide sold as Lasix)

have also been linked to progressive hearing loss.

However, the key to the preservation of old-age-hearing

of the Mabaan tribe may be their diet.

The reason the Mabaan researchers concluded that their diet

likely accounted for their lack of age-related hearing loss

is because they also appeared to lack something else:

coronary artery disease.

What kills more of us in the industrialized world than anything else

doesn't appear to touch them at all.

Their blood pressures are also perfect their whole lives

at about 110 over 70 into their 70s while we, on average, become hypertensive,

exceeding 130/80, starting in our 40s.

And no wonder—their diet is “almost free of animal protein”

and centered around whole grains.

So, they suggested, in addition to the absence of loud noise,

that atherosclerosis clogging the small blood vessels

feeding their inner ears may be the underlying cause

of age-related hearing loss in most of the rest of the world.

But you don't know until...you put it to the test,

which I'll cover next, after dealing with a supplement

shown to slow age-related hearing loss.