Tinnitus

Silencing the Ring

Susan J. Seidel, an otologist (hearing specialist) at the Greater Baltimore Medical Center, knows exactly how she developed the cicada-like chirp in her left ear.

"I was standing outside an airport, waiting to get on a plane, when a jet taxied toward our line," she recalls. "When it got close, it revved one of its engines to make a turn. The sound was so intense, I remember, that I clenched my teeth and thought 'Good grief, that's loud.' "

The blast lasted only a few seconds, but it set off the buzz that has pretty much stayed with her for more than 20 years. "I've gotten used to it, and lucky for me, it's in only one ear. But it has made me more interested in helping other people who have the same problem," she says.

Like Seidel, most of us have noticed that our ears can play their own tune for a time after being blasted by loud music or machinery, firecrackers or gunshots. Usually, the sound is barely noticeable, lasting anywhere from a few minutes to a couple of days.

For people with a condition called tinnitus, though, the ringing, hissing or buzzing becomes a persistent presence. Tinnitus, which in Latin means "tinkling like a bell," has been reported to reach volumes as high as 70 decibels. That's equivalent to having a vacuum cleaner in your head.

Tinnitus occurs when nerve cells in the cochlea, the tiny, snail shell-shaped inner ear, are damaged, explains Michael Seidman, M.D., director of the Tinnitus Center at the Henry Ford Hospital in Detroit. These nerves project hairlike endings into the cochlea, which is filled with fluid that moves in waves in response to sounds traveling through the ear. When a sound sends waves through the cochlea, the hairlike endings send a signal to the brain that gets interpreted as sound. When the sounds are too loud and the waves through the cochlea are too intense, the tiny nerve endings become damaged and may send abnormal signals that can cause hissing or buzzing.

Noise-induced spasms of the tiny arteries feeding the inner ears can also damage the tiny hairlike cells by cutting off their blood supply. The nerve cells can also be damaged by viruses, high blood pressure, high blood cholesterol and high insulin levels as well as by drugs, particularly aspirin and the
-mycin antibiotics. Aminoglycosides such as gentamicin, which are often used to treat pneumonia, are probably the number one offenders, says Dr. Seidman. Tinnitus is often one symptom of Ménière's disease, a condition that is caused by excess fluid pressure in the inner ear.

Finally, degeneration of the aging ear, usually because of poor circulation, accounts for a large percentage of cases.

If you develop tinnitus, it's important to see a doctor to make sure that you don't have a tumor on an ear nerve or a damaged ear membrane, Dr. Seidman says. Both are treatable conditions.

While most doctors don't yet use nutrition to treat tinnitus, there is some intriguing new research, mostly from Israel, that holds promise for some people with this condition. Here's what doctors say may help.

Vitamin B₁₂ Sheathes Ear Nerves

When it comes to nerves, vitamin B₁₂ plays a special role. The body needs this nutrient to manufacture myelin, the fatty sheath that wraps around nerve fibers, insulating them and allowing them to conduct their electrical impulses normally.

A vitamin B₁₂ deficiency can raise blood levels of homocysteine, an amino acid that is thought to be toxic to nerves. Low levels of B₁₂ have been linked to a number of nervous system disorders, including memory loss, decreased reflexes, impaired touch or pain perception--and, apparently, tinnitus and noise-induced hearing loss.

Researchers from the Institute for Noise Hazards Research and Evoked Potentials Laboratory at Chaim-Sheba Medical Center in Ramat Gan and from Tel Aviv University, both in Israel, looked at a group of 385 people with tinnitus and found that 36 to 47 percent suffered from vitamin B₁₂ deficiency. All of the people low in B₁₂ received injections of 1,000 micrograms weekly for four to six months. At the end of that time, their hearing and tinnitus were evaluated. Fifty-four percent reported improvement in their tinnitus, and approximately one-fourth reported reductions in the measured loudness of their tinnitus, according to Joseph Attias, D.Sc., head of the institute and one of the study's main researchers.

"Vitamin B₁₂ deficiency is somehow associated with chronic tinnitus," says Dr. Attias. "Long-term exposure to noise may deplete body levels of B₁₂ and so make the ears more vulnerable to noise-induced damage."

Most of the people in this study had tinnitus for six years or longer. "It's possible that people who are treated earlier for vitamin B₁₂ deficiency may have more improvement in their tinnitus than occurred in this study," says Dr. Attias.

If you have tinnitus, and especially if you also have memory problems, ask your doctor to check your blood level of vitamin B₁₂, he suggests.

Although most people get enough vitamin B₁₂ from foods, absorption problems can cause shortages, especially in older people. Strict vegetarians, who eat no meats, dairy products or eggs, are also at risk for deficiency, since B₁₂ comes only from animal foods.

If your doctor determines that you have absorption problems, you'll need vitamin B₁₂ shots for the rest of your life. If you don't have absorption problems, experts say that it's safe to take about 1,000 micrograms of B₁₂ a day.

Magnesium May Shield Sensitive Ears

It's true that you won't find laboratory animals handling heavy artillery or using chain saws. But you can thank these creatures for another dietary recommendation for protecting ears: magnesium.

Magnesium-deficient lab animals exposed to noise have much more damage to the nerve cells in their cochleas than animals fed a diet adequate in magnesium, Dr. Attias says. What happens to these cells when the noise level gets too high? "The tiny hairs on these cells fuse or disappear, and they and their supporting cells eventually disintegrate, along with the nerve fibers going to these cells," explains Dr. Attias. Low levels of magnesium combined with noise exposure eventually deplete the cells' energy stores, leading to exhaustion, damage and death of the inner ear cells, he explains.

Low magnesium levels can also cause blood vessels, including the tiny arteries going to the inner ears, to constrict. (Remember, noise-induced vasospasm is thought to play a role in tinnitus.)

Human ears, even young, healthy, normal-hearing ones, can benefit from extra magnesium, Dr. Attias says. He found that Israeli soldiers who got an additional 167 milligrams of supplemental magnesium daily had less inner ear damage than soldiers getting placebos (blank look-alike pills). According to Dr. Attias, a more recent study showed that supplemental intake has this same protective effect against long-term noise exposure.

If you're faced with a noisy environment, you'll want to make sure that you're getting the Daily Value of magnesium, which is 400 milligrams, Dr. Attias says. Most people fall short in that regard, with men getting about 329 milligrams a day and women averaging 207 milligrams a day. Green vegetables, whole grains, nuts and beans are packed with magnesium. (If you're considering taking magnesium supplements, be sure to talk to your doctor first if you have heart or kidney problems.)

If your tinnitus includes a sensation of fullness in your ear and balance problems, experts recommend that you get adequate amounts of calcium and potassium as well. These additional symptoms could be a sign of Ménière's disease. (For the full details on treating Ménière's with nutrients, see page 381.)

Antioxidants May Help Spare Ears

Tinnitus is sometimes caused by impaired blood flow to the ears, which can happen in two ways, Dr. Seidman says. First, the tiny artery leading to the inner ear can get clogged with cholesterol, causing a kind of stroke in the ear, he explains. Second, loud noises can send this artery into spasm, reducing blood supply to the cochlea. In either case, an interrupted blood supply can lead to hearing problems.

That's where the antioxidant nutrients--vitamin C, vitamin E, beta-carotene and others--come in. "Antioxidants work by helping to prevent oxygen-caused damage to cell membranes," Dr. Seidman explains. Antioxidants also help keep arteries open and free of plaque buildup, experts say.

Dr. Seidman and some other ear doctors suggest that you consider a smorgasbord of antioxidant nutrients: 400 international units of vitamin E daily, 250 milligrams of vitamin C twice daily, 50 to 200 micrograms of the mineral selenium daily and about 50,000 international units of beta-carotene twice daily. Doses of selenium exceeding 100 micrograms daily can be toxic and should be taken only under medical supervision.

Zinc Can Make a Difference

Some parts of the body have much higher concentrations of certain vitamins and minerals than other parts. That's the case with the inner ear, which, like the retina of the eye, has a high concentration of zinc. That finding has led some doctors to speculate that zinc deficiency may play a role in inner ear problems such as tinnitus.

"We don't know much about how zinc works in the inner ear, but it's evident that the cochlea needs zinc to function properly," explains George E. Shambaugh, Jr., M.D., professor emeritus of otolaryngology and head and neck surgery at Northwestern University Medical School in Chicago. "Animals fed a diet low in zinc partially lose the ability to hear, and apparently, even the kind of marginal zinc deficiency often seen in older people worsens the hearing loss associated with ear damage from noise or aging." Zinc is involved in a wide array of functions, including helping to maintain healthy cell membranes and protecting cells from oxygen-related damage.

Dr. Shambaugh estimates that about 25 percent of the people he sees with severe tinnitus are zinc-deficient. Sometimes they also have poor appetite, hair loss, diminished taste or smell or skin problems. All of these symptoms are related to zinc deficiency. For these people, he recommends supplemental zinc, along with a potent multivitamin/mineral that supplies other nutrients.

Although Dr. Shambaugh and other ear, nose and throat specialists may initially give large doses of zinc, up to 150 milligrams a day, it's important to take no more than about 15 milligrams a day without medical supervision. Doctors monitor blood levels of zinc when they prescribe higher amounts. That's because zinc can be toxic in large doses. Zinc also interferes with copper absorption, so if you're taking high doses of zinc, you may need to take supplemental copper (the ratio that's generally recommended is 1 milligram of copper for every 10 milligrams of zinc). Copper, too, can be toxic, so follow your doctor's advice on this.

The Daily Value for zinc is 15 milligrams. According to Dr. Shambaugh, few people get 10 to 15 milligrams a day in their diets, while people over age 75 rarely get as much as 7 milligrams a day. Look to meats and shellfish for zinc; cooked oysters, beef, crab and lamb all offer good amounts.

Vitamin A May Aid Hearing

Like zinc, vitamin A is found in high concentrations in the cochlea. "All special sensory receptor cells, including the retina of the eye and the hair cells of the inner ear, depend upon vitamin A and zinc to function properly," Dr. Shambaugh says.

In one study, low blood levels of vitamin A were associated with decreased ability to hear. And in several studies, from 24 to 74 percent of people with tinnitus reported at least partial relief with vitamin A supplements.

"I recommend beta-carotene, which you can take without worrying about toxicity," Dr. Shambaugh says. (The body can use beta-carotene to make vitamin A.) He recommends taking 30 milligrams (about 50,000 international units) of beta-carotene twice a day.