A systematic review and meta-analysis has identified potentially associations between certain dietary factors and reduced tinnitus incidence.
In the study, published in BMJ Open, investigators examined 15 common dietary elements across 10 observational studies involving over 300,000 participants. Four dietary components emerged as statistically significant negative correlations with tinnitus prevalence: fruit intake, dietary fiber, caffeine consumption, and dairy product consumption. No statistically significant associations were found between the other examined dietary factors (carbohydrates, varied diets, eggs, fat, margarine, meat, sugar, protein, fish, vegetables, and water) and tinnitus.
"Existing evidence suggests that consuming fruit, dietary fiber, caffeine, and dairy may be associated with a reduced incidence of tinnitus," the study authors emphasized. "The primary underlying mechanisms may involve the protective effects of these diets on blood vessels and nerves as well as their anti-inflammatory and antioxidant properties," they continued.
The investigators quantified these potential protective effects, noting reductions in tinnitus occurrence of 35.1% (20.7%–46.8%) for fruit intake, 9.2% (1%–14.9%) for dietary fiber, 17.3% (10.8%–23.4%) for dairy products, and 10.2% (6.5%–13.8%) for caffeine intake. The findings remained consistent through sensitivity analyses.
Tinnitus, characterized by perceived sounds without external stimuli, affects approximately 14.4% of adults globally. The condition is associated with distress, depression, anxiety, and decreased quality of life. Current treatments vary widely, including psychological counseling, cognitive-behavioral therapy, sound therapy, pharmaceutical interventions, and various nonpharmacologic approaches—yet no universally effective treatment currently exists.
The study's methodology followed PRISMA guidelines, utilizing a mixed-effect model to aggregate maximally covariate-adjusted odds ratios across included studies. The investigators searched PubMed, Embase, Web of Science, and Cochrane Library databases for observational studies examining tinnitus presence or severity in adults. Two independent evaluators assessed study quality using the Newcastle-Ottawa Scale.
The investigators proposed several mechanisms by which these dietary components might influence tinnitus pathophysiology. Dietary fiber may improve insulin sensitivity, potentially protecting against inner ear disturbances caused by hyperinsulinemia. Fruit and dairy products could enhance blood vessel function, while caffeine's proposed benefits might stem from adenosine receptor blockade, dopamine release promotion, acetylcholinesterase activity inhibition, and sympathetic nerve stimulation.
The investigators acknowledged several limitations of their study, including the relatively small number of included articles, which may have prevented certain widely accepted beneficial dietary factors (such as vegetables and eggs) from demonstrating significant associations. Additionally, the predominance of cross-sectional studies in the analysis limited causal inference.
"It is crucial to interpret our findings cautiously because of the overall low quality of the evidence available," the study authors cautioned. They called for "further well-designed, large-scale, cross-population cohort studies" to verify these associations and better understand dosage effects.
This research, registered on PROSPERO (CRD42023493856), represented the first comprehensive attempt to systematically examine the epidemiologic relationship between dietary patterns and tinnitus incidence.
The authors declared having no competing interests.
