Folic Acid May Slow Hearing Loss
Editor: Here's some good news on the hearing loss prevention front. A
Dutch study shows that folic acid may reduce age-related hearing loss.
Here's the press release.
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Folic acid - a B vitamin already added to U.S. flour - may slow
age-related hearing loss, a Dutch study shows.
Folic acid is also known as folate. Folic-acid deficiency causes
birth defects and seems to contribute to heart disease and stroke.
The study looked at 728 Dutch men and women aged 50 to 70. Unlike the
U.S., the Netherlands does not require folic acid supplementation of
flour. Participants in the Dutch study had high blood levels of
homocysteine. Folic acid reduces homocysteine levels, so the Dutch study
participants apparently consumed very little folic acid.
Half the study participants got strong folic acid supplements - 800
micrograms per day, about twice what one would get in a multivitamin
pill. The other participants got an inactive placebo pill.
After three years, those who got folic acid pills had less
low-frequency hearing loss than did placebo recipients. The difference
was slight: 0.7 decibels. The smallest change in sound intensity most
people can notice is 1.0 decibels.
There was no slowing of high-frequency hearing loss. That may be
because high-frequency hearing loss begins earlier in life than age 50.
Researchers Jane Durga, Ph.D., of Wageningen University, Netherlands,
and colleagues suggest that by fortifying their flour with folic acid,
nations might lessen their citizens' age-related hearing loss.
If a little folic acid from flour is good, would more folic acid be
better? That's not known, suggests Robert A. Dobie, M.D., of the
University of California, Davis. Dobie's editorial accompanies the Durga
study in the Jan. 2 issue of Annals of Internal Medicine.
"If this [hearing] benefit applies to the entire population (a
big 'if') and continues to accrue each year (another big 'if'), one
might expect a 5-decibel reduction in age-related [hearing loss] over a
20-year period," Dobie calculates.
Such a shift would cut the percentage of 75-year-old men who need
hearing aids from 33% to 22%.
Dobie notes that much more study is needed to see whether the study
results - seen in people with low folic-acid intake - might apply to the
better-nourished U.S. population.
