Coffee and other products containing caffeine may help lower chances of developing tinnitus, a ringing or buzzing sound heard when none is present.

Brigham and Women's Hospital (BWH) researchers examined 65,000 women, aged 30 to 44. None of these subjects had ever experienced tinnitus in 1991, the time of the earliest data, used as a baseline for the report.

The Nurses' Health Study 2 used data from self-reported health and lifestyle reports. These included information about the condition, and these records from 2009 were used to determine onset rates. A total of 5,289 cases of tinnitus were reported over 18 years of follow-up surveys.

"We observed a significant inverse association between caffeine intake and the incidence of tinnitus among these women... [although] the reason behind this observed association is unclear," Gary Curhan, professor of medicine at Harvard Medical School and senior author of an article announcing the results of the study, said.

Women who consumed between 0.016 and 0.02 ounces a day of caffeine (the amount in four to five cups of coffee) developed tinnitus 15 percent less often than subjects in the study consuming one-third of that amount of the stimulant.

Caffeine stimulates the central nervous system, and affects physiology in the inner ear in both humans and other animals. That action may play a role in lowering incidence of tinnitus, but researchers are unable to isolate an underlying mechanism behind their findings.

Tinnitus usually occurs in younger and middle-aged women. It is not a condition in itself, but a symptom of an underlying disorder. Roughly one in five people are afflicted by it, for one reason or another. It can become more serious with age, but can often be treated, revealing the symptom.

Medical reports were created every two years and questionnaires about food choices were collected every four years.

Caffeine consumed by the women in the study was primarily in the form of coffee. Effectiveness of the stimulant on the disorder was nearly identical among subjects of all ages.

Curhan and his team told the press additional study will be needed to determine whether or not caffeine could reduce or eliminate symptoms of the condition. Researchers were quick to point out that despite this finding, people should not start consuming large quantities of the stimulant, which comes with its own set of risks. These include irregular heartbeat, nausea and vomiting. In extreme cases, overdoses of the stimulant can lead to death.

Study of the effect of caffeine on tinnitus was published in the American Journal of Medicine.