Dietary deficiencies in early childhood can lead to hearing problems, and type 2 diabetes (diet plays a big part) can lead to hearing loss. This I know, but general population diet?
(looks at some studies)
Ok, looks like most of this stuff is coming from cross sectional survey data, and not from longitudinal research that follows the same people over time. If you want my "studies health and medicine from a social science perspective take", it would be this:
poor diet is associated with worse health outcomes across the board.
Some studies:
(I am choosing links that should not be paywalled)
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To examine the associations between overall diet quality and hearing function among middle–older aged adults in the USA. Cross-sectional analysis. Diet quality was examined using the Mediterranean Diet Score (MDS), using data from a single 24 h ...
www.ncbi.nlm.nih.gov
Setting:
National Health and Nutrition Examination Surveys 2000–2006 and 2009–2012.
Participants:
Adults aged ≥50 years (
n 1639) with valid dietary and audiometry assessments.
Results:
After adjusting for potential confounders, a non-significant trend for a protective association of higher MDS was observed for hearing loss (OR = 0·78; 95 % CI 0·49, 1·23). A significant inverse association was observed for high-frequency hearing loss (OR = 0·64; 95 % CI 0·43, 0·95). No association was found for low-frequency hearing loss among women; however, higher MDS was significantly associated with higher odds of low-frequency hearing loss among men (OR = 2·63; 95 % CI 1·39, 4·95).
Conclusions:
Among middle–older aged adults, adherence to a Mediterranean-style diet was inversely associated with hearing loss, including those at high hearing frequencies, among older adults. However, a detrimental association was observed at low hearing frequencies among men. Future investigations with a longitudinal design are needed to clarify the associations between diet quality and hearing loss.
Here's one with a much larger sample from the UK:
Supplemental Digital Content is available in the text. Keywords: Diet, Dietary pattern, Hearing difficulties, Nutrients, Presbyacusis, Tinnitus
www.ncbi.nlm.nih.gov
Design:
The research was conducted using the UK Biobank resource. Tinnitus was based on report of ringing or buzzing in one or both ears that lasts more than five minutes at a time and is currently experienced at least some of the time. Identification of a hearing problem was based on self-reported difficulties with hearing. Usual dietary intake and dietary patterns (involving statistical grouping of intake to account for how foods are combined in real-life diets) were estimated based on between two and five administrations of the Oxford Web-Q 24-hour dietary recall questionnaire over the course of a year for 34,576 UK adult participants aged 40 to 69.
Results:
In a multivariate model, higher intake of vitamin B12 was associated with reduced odds of tinnitus, while higher intakes of calcium, iron, and fat were associated with increased odds (B12, odds ratio [OR] 0.85, 95% confidence interval [CI] 0.75 to 0.97; Calcium, OR 1.20, 95% CI 1.08 to 1.34; Iron, OR 1.20, 95% CI 1.05 to 1.37; Fat, OR 1.33, 95% CI 1.09 to 1.62, respectively, for quintile 5 versus quintile 1). A dietary pattern characterised by high protein intake was associated with reduced odds of tinnitus (OR 0.90, 95% CI 0.82 to 0.99 for quintile 5 versus quintile 1). Higher vitamin D intake was associated with reduced odds of hearing difficulties (OR 0.90, 95% CI 0.81 to 1.00 for quintile 5 versus quintile 1), as were dietary patterns high in fruit and vegetables and meat and low in fat (Prudent diet: OR 0.89, 95% CI 0.83 to 0.96; High protein: OR 0.88, 95% CI 0.82 to 0.95; High fat: OR 1.16, 95% CI 1.08 to 1.24, respectively, for quintile 5 versus quintile 1).
Conclusions:
There were associations between both single nutrients and dietary patterns with tinnitus and hearing difficulties. Although the size of the associations was small, universal exposure for dietary factors indicates that there may be a substantial impact of diet on levels of tinnitus and hearing difficulties in the population. This study showed that dietary factors might be important for hearing health.
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Note the second study uses self reports, the first uses measures of hearing. Most studies I looked at find similar results.
So eat well, that will help all health conditions not just hearing loss. But trying to take the results of these studies to do something like supplement with B12 is not really something I would ever consider.
And one reason is that longitudinal studies show cross sectional population study results often don't hold up:
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Background: With the aging population, the prevalence of age-related hearing loss will increase substantially. Prevention requires more knowledge on modifiable risk factors. Obesity and diet quality have been suggested to play a role in the etiology ...
www.ncbi.nlm.nih.gov
Methods: We performed cross-sectional and longitudinal analyses (follow-up: 4.4 years) in the population-based Rotterdam Study. At baseline (2006-2014), 2,906 participants underwent assessment of body composition, diet, and hearing. Of these 2,906 participants, 636 had hearing assessment at follow-up (2014-2016). Association of body composition and of diet quality with hearing loss were examined using multivariable linear regression models.
Results: Cross-sectionally, higher body mass index and fat mass index were associated with increased hearing thresholds.
These associations did not remain statistically significant at follow-up. We found no associations between overall diet quality and hearing thresholds. (emphasis added)
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This is a general pattern for research linking diet and health outcomes in terms of specific diseases or conditions. Population studies will show a significant but small effect, follow up longitudinal studies show much weaker or no effect. Happens all the time, for a variety of issues.
FWIW, that's my take on this specific issue. After a good 10 minutes of research, admittedly, but after close to 30 years looking at this kind of thing I should be pretty efficient at it!