If you're middle-aged or older, you've probably heard about—or experience for your self—"age-related" hearing loss. Many people do lose some of their hearing with advancing age. That's the bad news.
The good news is that recent research has shown that much of this hearing loss can be prevented with certain nutrients. The right foods and supplements actually can help you hear better.
Exposure to loud noises over a lifetime is a major cause of presbycusis, hearing loss that is associated with age and heredity. A structure in the inner ear called the cochlea is lined with thousands of tiny hairs that translate sound vibrations into electrical signals. Noise can damage these hairs and, over time, may result in hearing loss.
Why this happens: Loud noises trigger the production of free radicals, molecules produced in the inner ear that damage the cochlear hairs. Prolonged exposure to noise also causes a constriction of blood vessels and reduces circulation to the inner ear.
In laboratory studies at the University of Michigan, animals were exposed to sounds measuring 120 decibels, about the volume of a rock concert.
During this research, some animals were given the antioxidant-rich nutrients magnesium, beta-carotene (the body converts beta-carotene to vitamin A) and vitamins C and E one hour prior to the noise exposure and then once daily for five days. The test animals had 75% to 80% less hearing loss than animals given their normal food.
Why Nutrition Helps
The antioxidants in fruits, vegetables, whole grains and other plant foods help fight free radicals and inflammation throughout the body, including in the inner ear. People who consume a lot of these nutrients on a regular basis get the most protection because free radical damage persists even when the noise is gone.
The largest spike in free radicals occurs while the noise is present. After that, free radicals intermittently decline and spike again. This cycle continues for five to seven days after the initial exposure, probably because free radicals are produced by the body as it attempts to heal noise-related damage within the inner ear. Recommended nutrients…
Taken together, the combination of nutrients beta-carotene, magnesium and vitamins C and E seems to be most effective at preventing cell damage. Each one inhibits the formation of free radicals in cells in different parts of the body. Vitamin E and beta-carotene reduce free radicals that are formed in the lipid (fatty) portions of cells, while vitamin C acts in the watery compartments. Magnesium dilates blood vessels, improves inner-ear circulation and prevents a noise-induced reduction in blood flow followed by a rebound increase (which would lead to an additional increase in free radicals).
Recommended doses: 18 milligrams (mg) beta-carotene. 500 mg vitamin C...267 mg vitamin E (in the form of alpha-tocopherol)... and 312 mg magnesium. These doses are the equivalents of those used in the studies and are only slightly different from the minimum recommended levels.
Studies have shown that the best time to take nutritional supplements to protect your hearing is about 24 hours before an anticipated noise exposure, such as a concert or a car race.
When you're exposed to loud noises that you didn't anticipate, you can gain protection by increasing your antioxidant intake afterward. Antioxidants have been shown to reduce noise damage in animals when taken as much as three days following noise exposure-although protection was greater when taken one day after the noise.
The Blue Mountains Hearing Study (a survey of age-related hearing loss) collected data on dietary habits and measured levels of hearing loss in nearly 3,000 participants. Those with the lowest blood levels of folate were 39% more likely to experience hearing loss than those with the highest levels. Folate—the supplemental form is folic acid-is an antioxidant that also lowers levels of homocysteine, an amino acid that indicates the presence of inflammation in the body. Reducing homocysteine with folate or folic acid may reduce inflammatory damage and possibly improve circulation to the inner ear.
Recommended dose: I advise patients to get 400 micrograms (mcg) daily. You can get this much in one or two servings of many fortified breakfast cereals. Most multi-nutrient supplements also include folic acid. Foods rich in folate include spinach (100 mcg in one-half cup cooked) and asparagus (85 mcg in four spears).
Omega-3 Fatty Acids
In the Blue Mountains Hearing Study, those who ate fish two or more times a week were 42% less likely to suffer from age-related hearing loss than those who ate less than one weekly serving of fish.
Recommended: The omega-3 fatty acids in fish are among the healthiest nutrients you can eat. Two or more fish servings a week are probably ideal.
This mineral is a chelator that binds to iron and helps remove it from the body. This process is important for hearing because iron plays a role in the formation of free radicals.
Recommended dose: The recommended daily allowance (RDA) is 11 mg zinc for men and 8 mg for women. A serving of beef can supply nearly 9 mg of zinc. Oysters, the richest source, provide 76.7 mg in a half-dozen.