Folic acid -- a B vitamin also known as folate -- helps the body create new cells. Earlier studies have found that people with low intake of folic acid tend to have poor hearing.
To test whether dietary supplementation of folate could affect hearing loss in old age, researchers from the Nestle Research Center in Lausanne, Switzerland -- led by Dr. Jane Durga -- recruited 728 participants between the ages of 50 and 70.
The participants were screened for health conditions that affected their hearing, then were split into two groups. The researchers randomly assigned the study members to either receive 800 micrograms of folate per day for three years, or an inactive placebo every day.
At the study's conclusion, the group that had been supplemented with folic acid experienced an increase in their low-frequency hearing threshold of 1.0 dB. The participants in the placebo group experience a significantly smaller improvement in low-frequency hearing threshold.
However, both groups experienced similar declines in high-frequency auditory acuity, the researchers found.
Because study participants in the Netherlands -- where fortifying foods with folate is prohibited -- had roughly half the folic acid levels of typical American adults, the researchers were unsure if the study's results could be applied to Americans.