Dietary glycemic load is a predictor of age-related hearing loss in older adults

Associations between Plant-Based Dietary Patterns and Sensory Impairments among Chinese Older Adults: Based on the Chinese Longitudinal Healthy Longevity Survey

INTRODUCTION

The aim of this study was to investigate the relationship between the plant-based dietary index and vision impairment (VI), hearing impairment (HI), and dual sensory impairment (DSI) among Chinese aged 65 and older.

METHODS

Based on the 2018 data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a cross-sectional study was conducted on 14,859 samples. The assessment of dietary quality utilized the plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI). Logistic regression analysis was used to examine the associations between PDIs and sensory impairments. Additionally, restricted cubic spline analysis was utilized to investigate the nonlinear association between PDIs and sensory impairments.

RESULTS

Participants in the highest quintile of PDI exhibited reduced prevalence of VI (OR 0.78, 95% CI: 0.67-0.90, ptrend <0.001), HI (OR 0.83, 95% CI: 0.70-0.99, ptrend <0.001), and DSI (OR 0.62, 95% CI: 0.51-0.77, ptrend <0.001) relative to those in the lowest quintile. Moreover, individuals who ranked in the highest quintile for hPDI exhibited a 25% reduced risk of VI disease. Conversely, those in the highest quintile of uPDI were associated with increased prevalence of VI (OR 1.37, 95% CI: 1.17-1.61, ptrend <0.001), HI (OR 1.36, 95% CI: 1.12-1.65, ptrend <0.001), and DSI (OR 1.56, 95% CI: 1.25-1.95, ptrend <0.001). The relationship between PDIs increasing by every 10 units and sensory impairments showed similar patterns. Notably, hPDI demonstrated a nonlinear relationship with HI (pfor nonlinearity = 0.001), while the others exhibited linear associations.

CONCLUSION

The increase in PDI and hPDI correlates with a reduced prevalence of one or more sensory impairments. Conversely, an increase in uPDI is associated with an elevated prevalence of multiple sensory impairments. Our study findings emphasize the significance of plant-based food quality, advocating for adherence to a plant-based dietary pattern while reducing the intake of less healthy plant foods and animal-based products.

Association between caffeine intake from foods and beverages in the diet and hearing loss in United States adults

Background

Hearing loss (HL) is the third most prevalent condition, significantly affecting individuals and society. Recent research has explored the potential impact of nutrition, particularly caffeine intake, on HL. While some studies focus on coffee, caffeine intake should be assessed across all dietary sources. This study examines the association between dietary caffeine intake and HL.

Methods

Our cross-sectional study included 6,082 participants from the National Health and Nutrition Examination Survey (NHANES). Participants were divided into two groups based on their median caffeine intake: low and high. The study investigated two types of HL: speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL). Binary logistic regression analyzed the correlation between caffeine intake and HL, and a restricted cubic spline (RCS) model assessed potential non-linear associations. Subgroup analyses were also conducted.

Results

High caffeine intake was associated with significantly higher rates of SFHL and HFHL compared to low intake (SFHL: 15.4% vs. 10%, HFHL: 30.5% vs. 20.6%, both p < 0.001). Unadjusted logistic regression showed a higher likelihood of SFHL (OR[95%CI] = 1.65[1.41-1.92]) and HFHL (OR[95%CI] = 1.69[1.50-1.90]) in high caffeine consumers. After adjusting for confounders, high caffeine intake remained significantly associated with SFHL (OR[95%CI] = 1.35[1.09-1.66]) but not HFHL (OR[95%CI] = 1.14[0.96-1.35]). The RCS model indicated a linear increase in the risk of SFHL and HFHL with higher caffeine intake (non-linear p = 0.229 for SFHL, p = 0.894 for HFHL). Subgroup analysis revealed that increased caffeine intake was linked to higher SFHL and HFHL risks in participants under 65 years but not in those 65 years and older (SFHL: p for interaction = 0.002; HFHL: p for interaction <0.001).

Conclusion

Our study indicates a strong correlation between dietary caffeine intake and the risk of HL in American adults, particularly those under 65. High caffeine intake was linked to an increased risk of SFHL, but not HFHL, after adjusting for relevant variables.

The significance of serum Klotho to hearing loss: a potential protector under noise pollution

The issue of hearing protection in the presence of noise pollution is of great importance in the fields of environmental science and clinical medicine. Currently, the clinical significance of Klotho in relation to hearing has not been revealed. The aim of this study was to examine the correlation between serum Klotho levels and Pure Tone Average (PTA) hearing thresholds among individuals in the U.S.. The analysis involved a sample of 1,781 individuals aged 20 to 69, obtained from the 2007-2012 National Health and Nutrition Examination Survey. Various methods were utilized for the analysis, including univariate and multivariate linear regression, stratified analysis, smooth curve fitting, a two-segment linear regression model, and log-likelihood ratio analysis. The results of the univariate analysis indicated that serum Klotho concentration, age, education level, hypertension, diabetes, and smoking all exhibited a significant influence on PTAs. After adjusting for potential confounding factors, it was observed that a decrease in serum Klotho was significantly associated with PTA thresholds at low frequency (β = -0.002; 95% CI: -0.003, -0.001; P = 0.004), speech frequency (β = -0.002; 95% CI: -0.003, -0.001; P = 0.007), and high frequency (β = -0.002; 95% CI: -0.003, -0.001; P = 0.045). Specifically, for every 1 pg/ml decrease in serum Klotho concentration, the PTAs increased by 0.002 dB. Moreover, age and gender-specific analyses revealed significant associations. For individuals aged 59-69, a significant association was found between serum Klotho concentration and high-frequency PTA (β = -4.153; 95% CI: -7.948, -0.358; P = 0.032). Additionally, among females, significant associations were observed between serum Klotho concentration and speech-frequency PTA (β = -1.648, 95% CI: -3.197, -0.099; P = 0.037) as well as high-frequency PTA (β = -3.046; 95% CI: -5.319, -0.772; P = 0.009). Finally, the results of smooth curve fitting and threshold effect analyses indicated a potential negative linear correlation between serum Klotho concentration and PTA thresholds. In conclusion, a lower level of serum Klotho was found to be associated with increased hearing thresholds, particularly among the elderly population. This finding has significant implications for the prevention and treatment of hearing damage.

Associations of Dietary Intake With Self-Reported Hearing Loss: Findings From the Survey of the Health of Wisconsin

PURPOSE

The purpose of this study was to evaluate associations of dietary intake components with hearing loss.

METHOD

Participants were from the population-based Survey of the Health of Wisconsin. The Block food frequency questionnaire measured dietary intake of carbohydrates, fiber, protein, free (added) sugars, fruits, vegetables, saturated and trans fats, and glycemic index. Intake was categorized into quintiles (Q). Hearing loss was self-reported. Logistic regression models were used to evaluate associations of dietary determinants with hearing loss. Results are presented as odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs). Final models were adjusted for age, sex, total energy intake, race/ethnicity, education, smoking, and regular physical activity.

RESULTS

There were 2,839 participants (56% women; M_age = 48.2 [SD = 14.5] years) included. Higher consumption of trans fat (Q5: OR = 1.83, 95% CI [1.27, 2.64]) and higher glycemic index (Q5: OR = 1.34, 95% CI [1.00, 1.80]) were associated with increased odds of hearing loss. Hearing loss was associated with fruit, saturated- and trans-fat intake in women, and trans-fat intake and glycemic index in men.

CONCLUSIONS

Dietary intake was associated with self-reported hearing loss. Research on mechanistic pathways of associations and public health interventions to prevent hearing loss is needed.

A Narrative Review of Lifestyle Risk Factors and the Role of Oxidative Stress in Age-Related Hearing Loss

Age-related hearing loss affects a significant proportion of adults aged 60 years and above, with a prevalence of 65%. This condition has a negative impact on both physical and mental well-being, and while hearing interventions can help alleviate the effects of hearing loss, they cannot completely restore normal hearing or halt the progression of age-related hearing loss. Oxidative stress and inflammation have been identified as potential contributors to this condition. By addressing modifiable lifestyle risk factors that exacerbate oxidative stress, there may be an opportunity to prevent hearing loss. Therefore, this narrative review provides an overview of the major modifiable lifestyle risk factors associated with age-related hearing loss, that is, exposure to noise and ototoxic chemicals, smoking, diet, physical activity, and the presence of chronic lifestyle diseases, and offers an overview of the role of oxidative stress in the pathophysiology of this condition.

Association of dietary factors with noise-induced hearing loss in Korean population: A 3-year national cohort study

Noise-induced hearing loss (NIHL) is a hearing impairment (HI) caused by various clinical factors. Identifying the relationship between NIHL and nutrient consumption could help in reducing the prevalence of hearing loss. The aim of this study was to analyze the relationship between NIHL and dietary factors using data of the Korea National Health and Nutrition Examination survey (KNHANES). The data were collected from The Fifth KNHANES 2010-2012. The survey was taken by a total of 10,850 participants aged 20-65 years. Air conduction audiometry was measured at 500, 1000, 2000, and 4000 Hz in both ears. Metabolic syndrome, noise exposure, alcohol consumption, smoking, income level, marital status, and nutritional intake were evaluated. The differences between non-HI and HI participants in the noise-exposed group showed statistically significant differences in age, sex, marital and smoking status, alcohol consumption, and fasting glucose and triglyceride levels (p<0.05). In a multiple regression analysis of the noise-exposed group, age showed a significant association with HI (OR: 0.604; 95% CI: 0.538-0.678) after adjusting for confounders. In multivariate analysis for dietary factors affecting HI in noise-exposed groups, retinol (OR: 1.356; 95% CI: 1.068-1.722), niacin (OR: 1.5; 95% CI: 1.022-2.201), and carbohydrates (OR: 0.692; 95% CI: 0.486-0.985) showed a significant association with NIHL. Age was identified as the only factor significantly affecting NIHL. When the dietary factors of the noise-exposed group were analyzed, high intake of niacin and retinol and low intake of carbohydrates appeared to reduce the risk of hearing loss.

Effects of Diet and Lifestyle on Audio-Vestibular Dysfunction in the Elderly: A Literature Review

BACKGROUND

The world's age-related health concerns continue to rise. Audio-vestibular disorders, such as hearing loss, tinnitus, and vertigo, are common complaints in the elderly and are associated with social and public health burdens. Various preventative measures can ease their impact, including healthy food consumption, nutritional supplementation, and lifestyle modification. We aim to provide a comprehensive summary of current possible strategies for preventing the age-related audio-vestibular dysfunction.

METHODS

A PubMed, Embase, and Cochrane review databases search was conducted to identify the relationship between diet, lifestyle, and audio-vestibular dysfunction. "Diet", "nutritional supplement", "lifestyle", "exercise", "physical activity", "tinnitus", "vertigo" and "age-related hearing loss" were used as keywords.

RESULTS

Audio-vestibular dysfunction develops and progresses as a result of age-related inflammation and oxidative stress. Diets with anti-inflammatory and antioxidant effects have been proposed to alleviate this illness. A high-fat diet may induce oxidative stress and low protein intake is associated with hearing discomfort in the elderly. Increased carbohydrate and sugar intake positively correlate with the incidence of audio-vestibular dysfunction, whereas a Mediterranean-style diet can protect against the disease. Antioxidants in the form of vitamins A, C, and E; physical activity; good sleep quality; smoking cessation; moderate alcohol consumption; and avoiding noise exposure are also beneficial.

CONCLUSIONS

Adequate diet or nutritional interventions with lifestyle modification may protect against developing audio-vestibular dysfunction in elderly individuals.

Prevalence of Self-Reported Hearing Loss and Associated Risk Factors: Findings From the Survey of the Health of Wisconsin

PURPOSE

The purpose of this study was to determine the prevalence of self-reported hearing loss and associated risk factors in a representative population-based study of Wisconsin residents.

METHOD

Survey of the Health of Wisconsin participants with data on self-reported hearing loss were included. We reported prevalence of self-reported hearing loss with corresponding 95% confidence intervals (CIs), overall, and stratified by age and sex. Age- and sex-adjusted and multivariable logistic regression models were used to evaluate determinants of self-reported hearing loss, and results are presented as odds ratios with corresponding 95% CIs.

RESULTS

There were 2,767 participants (50.7% men) with a mean age of 46 years (range: 21-74) in this study. Prevalence of self-reported hearing loss was 26.8% (24.4, 28.4) and was higher in men (30.3% [27.1, 33.4]) than in women (22.5% [19.9, 25.0]). Prevalence increased with age. After multivariable adjustment, age (per +1 year increase; 1.05 [1.04, 1.06]), male sex (1.57 [1.18, 2.08]), having two chronic diseases (vs. 0; 1.93 [1.16, 3.23]), occupational (2.47 [1.91, 3.19]) and recreational (1.58 [1.22, 2.04]) noise exposure, and poor diet (1.88 [1.28, 2.78]) were associated with higher odds of self-reported hearing loss.

CONCLUSIONS

Hearing loss is a highly prevalent public health concern and may be at least partially modifiable via interventions to reduce noise exposure and promote health. Statewide prevalence and risk factor data can be used to inform public health practice and promote hearing loss prevention.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19661130.

Multidimensional Risk Factors of Age-Related Hearing Loss Among Malaysian Community-Dwelling Older Adults

Purpose

This study evaluates the prevalence of and the multidimensional risk factors associated with age-related hearing loss (ARHL) among community-dwelling older adults in Malaysia.

Patients and Methods

A total of 253 participants aged 60 years and above participated in this cross-sectional study. The participants were subjected to pure tone audiometric assessment. The hearing threshold was calculated for the better ear and classified into pure-tone average (PTA) for the octave frequencies from 0.5 to 4 kHz and high-frequency pure-tone average (HFA) for the octave from 2 to 8kHz. Then, the risk factors associated with PTA hearing loss (HL) and HFAHL were identified by using multivariate logistic regression analysis.

Results

The prevalence of ARHL based on PTA and HFA among the community-dwelling older adults was 75.5% and 83.0%, respectively. Following multifactorial adjustments, being older (OR: 1.239; 95% CI: 1.062–1.445), having higher waist circumference (OR: 1.158; 95% CI: 1.015–1.322), lower intake of niacin (OR: 0.909; 95% CI: 0.831–0.988) and potassium (OR: 0.998; 95% CI: 0.996–1.000), and scoring lower in RAVLT T5 (OR: 0.905; 95% CI: 0.838–0.978) were identified as the risk factors of PTAHL. Meanwhile, being older (OR: 1.117; 95% CI: 1.003–1.244), higher intake of carbohydrate (OR: 1.018; 95% CI: 1.006–1.030), lower intake of potassium (OR: 0.998; 95% CI: 0.997–0.999), and lower scores on the RAVLT T5 (OR: 0.922; 95% CI: 0.874–0.973) were associated with increased risk of having HFAHL.

Conclusion

Increasing age, having higher waist circumference, lower intake of niacin and potassium, higher intake of carbohydrates and having lower RAVLT T5 score were associated with increased risk of ARHL. Modifying these risk factors may be beneficial in preventive and management strategies of ARHL among older persons.

Black Older Americans Have Lower Prevalence of Hearing Loss Than Their White Peers: Findings From Two Large Nationally Representative Surveys

PURPOSE

The purpose of this study was to investigate Black-White differences associated with hearing loss among older adults living in the United States.

METHOD

Secondary data analysis was conducted using the 2017 American Community Survey (ACS) with a replication analysis of the 2016 ACS. The ACS is an annual nationally representative survey of Americans living in community settings and institutions. The sample size of older Americans (age 65+ years) in 2017 was 467,789 non-Hispanic Whites (NHWs) and 45,105 non-Hispanic Blacks (NHBs). In the 2016 ACS, there were 459,692 NHW and 45,990 NHB respondents. Measures of hearing loss, age, race/ethnicity, education level, and household income were based on self-report. Data were weighted to adjust for nonresponse and differential selection probabilities.

RESULTS

The prevalence of hearing loss was markedly higher among older NHWs (15.4% in both surveys) in comparison with NHBs (9.0% in 2017 and 9.4% in 2016, both ethnic differences p < .001). In the 2017 ACS, the age- and sex-adjusted odds of hearing loss were 69% higher for NHWs compared with NHBs, which increased to 91% higher odds when household income and education level were also taken into account (OR = 1.91; 95% confidence interval [CI; 1.85, 1.97]). Findings from the 2016 ACS were very similar (e.g., 65+ fully adjusted OR = 1.81; 95% CI [1.76, 1.87]).

CONCLUSIONS

NHWs have a much higher prevalence and almost double the odds of hearing loss compared with NHBs. Unfortunately, the ACS survey does not allow us to explore potential causal mechanisms behind this association.

Dietary Fibre Intake and the 10-Year Incidence of Tinnitus in Older Adults

Tinnitus is the phantom perception of sound in the ears or head that increases in prevalence as age increases. With strong evidence supporting the benefits of dietary fibre for vascular health and hearing loss, intake of dietary fibre may also have a role in the prevention of tinnitus symptoms. This longitudinal study aims to determine the association between the intake of dietary fibre and other carbohydrate nutrition variables including glycaemic index (GI), glycaemic load (GL) and total carbohydrate intakes, and incident tinnitus over 10 years. Of the 1730 participants (aged ≥50 years) from the Blue Mountains Hearing Study with complete baseline data on tinnitus symptoms and carbohydrate intakes, 536 (31%) cases of tinnitus were identified and excluded from further incidence analysis. Dietary data were collected using a validated semi-quantitative food frequency questionnaire to determine intakes of total dietary fibre and fibre contributions from cereals, vegetables, and fruit. A purpose-built database based on Australian GI values was used to calculate mean GI. Lower versus higher intakes of fruit fibre (≤3.6 g/day vs. >3.6 g/day) and cereal fibre (≤4.2 g/day vs. >4.2 g/day) were significantly associated with a 65% (HR = 1.65; 95% CI: 1.15–2.36) and 54% (HR = 1.54; 95% CI: 1.07–2.22) increased risk of developing tinnitus over 10 years, respectively. Associations between intake of other carbohydrate nutrients and incident tinnitus were mostly non-significant. In summary, our study showed modest associations between intake of dietary fibre and incident tinnitus. The protective effects of fibre, particularly insoluble fibre, could underlie observed associations by reducing the risk of tinnitus via vascular risk factors such as cardiovascular disease. Further longitudinal studies evaluating different types and sources of fibre and tinnitus risk are needed to confirm our study findings.

Relationship Between Diet, Tinnitus, and Hearing Difficulties

OBJECTIVES

Diet may affect susceptibility of the inner ear to noise and age-related effects that lead to tinnitus and hearing loss. This study used complementary single nutrient and dietary pattern analysis based on statistical grouping of usual dietary intake in a cross-sectional analysis of tinnitus and hearing difficulties in a large population study sample.

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.

Dietary Habits and Nutrient Intakes Are Associated to Age-Related Central Auditory Processing Disorder in a Cohort From Southern Italy

Objectives

Central auditory processing disorder (CAPD) commonly occurs in older age. However, few studies of a possible link between age-related CAPD and diet in an older population have been conducted. The objective of the present study was to investigate the relationship between eating habits and age-related CAPD in a population >65 years, using cross-sectional and retrospective data obtained in the same population-based study about 12 years ago.

Methods

We selected 734 participants (403 men) from a large population-based study. For age-related CAPD assessment, we used the Synthetic Sentence Identification with Ipsilateral Competitive Message test. Dietary habits were assessed by a Food Frequency Questionnaire. Associations between age-related CAPD and food groups/macro-and micronutrients were explored using adjusted logistic regression models.

Results

Age-related CAPD subjects consumed more dairy (111 vs. 98 g/d), olives and vegetable oil (63 vs. 52 g/d) and spirits (2 vs.1 g/d), and less fruits (536 vs. 651 g/d) in the cross-sectional analysis. Age-related CAPD subjects had a lower intake of potassium, vitamin C, and a higher fat intake. Further analyses identified dietary fiber as being inversely related to age-related CAPD.

Discussion

The present study provided evidence that the dietary hypotheses proposed for explaining the development of cognitive disorders in older age might also hold for age-related CAPD. Further data from other large and prospective population-based studies are needed for confirming these findings.

Body mass index, waist circumference, and risk of hearing loss: a meta-analysis and systematic review of observational study

BACKGROUND

Emerging evidence implicates excess weight as a potential risk factor for hearing loss. However, this association remained inconclusive. Therefore, we aimed to systematically and quantitatively review the published observational study on the association between body mass index (BMI) or waist circumference (WC) and hearing loss.

METHODS

The odds ratios (ORs) or relative risks (RRs) with their 95% confidence intervals (CIs) were pooled under a random-effects model. Fourteen observational studies were eligible for the inclusion in the final analysis.

RESULTS

In the meta-analysis of cross-sectional studies, the ORs for prevalent hearing loss were 1.10 (95% CI 0.88, 1.38) underweight, 1.14 (95% CI 0.99, 1.32) for overweight, OR 1.40 (95% CI 1.14, 1.72) for obesity, 1.14 (95% CI 1.04, 1.24) for each 5 kg/m2 increase in BMI, and 1.22 (95% CO 0.88. 1.68) for higher WC. In the meta-analysis of longitudinal studies, the RRs were 0.96 (95% CI 0.52, 1.79) for underweight, 1.15 (95% CI 1.04, 1.27) for overweight, 1.38 (95% CI 1.07, 1.79) for obesity, 1.15 (95% CI 1.01, 1.30) for each 5 kg/m2 increase in BMI, and 1.11 (95% CI 1.01, 1.22) for higher WC.

CONCLUSIONS

In summary, our findings add weight to the evidence that elevated BMI and higher WC may be positively associated with the risk of hearing loss.

Role of nutrition in the development and prevention of age-related hearing loss: A scoping review

Age-related hearing loss (ARHL) is a major and increasingly prevalent health problem worldwide, causing disability and social isolation in the people who present it. This impairment is caused by genetic and environmental factors. Nutritional status has been identified as a related risk associated with hearing loss (HL). This scoping review aimed to characterize the links between HL and nutritional status. PubMed, Embase, Cochrane and Scopus databases were searched up to December 2019. Studies examining the relation between nutrition and dietary habits and HL were included. After screening 3510 citations, 22 publications were selected for inclusion in the current review, all of which were published between 2010 and 2019. Diets rich in saturated fats and cholesterol have deleterious effects on hearing that could be prevented by lower consumption. Conversely, greater consumption of fruit and vegetables, and of polyunsaturated fatty acids (omega-3) and anti-oxidants in the form of vitamins A, C, and E, prevent the development of ARHL. The current literature suggests a possible association between nutritional status and hearing loss. More studies are needed to better characterize the clinical consequences of this association.

The role of diet in vulnerability to noise-induced cochlear injury and hearing loss

The influence of dietary nutrient intake on the onset and trajectory of hearing loss during aging and in mediating protection from challenges such as noise is an important relationship yet to be fully appreciated. Dietary intake provides essential nutrients that support basic cellular processes related to influencing cellular stress response, immune response, cardiometabolic status, neural status, and psychological well-being. Dietary quality has been shown to alter risk for essentially all chronic health conditions including hearing loss and tinnitus. Evidence of nutrients with antioxidant, anti-inflammatory, and anti-ischemic properties, and overall healthy diet quality as otoprotective strategies are slowly accumulating, but many questions remain unanswered. In this article, the authors will discuss (1) animal models in nutritional research, (2) evidence of dietary nutrient-based otoprotection, and (3) consideration of confounds and limitations to nutrient and dietary study in hearing sciences. Given that there are some 60 physiologically essential nutrients, unraveling the intricate biochemistry and multitude of interactions among nutrients may ultimately prove infeasible; however, the wealth of available data suggesting healthy nutrient intake to be associated with improved hearing outcomes suggests the development of evidence-based guidance regarding diets that support healthy hearing may not require precise understanding of all possible interactions among variables. Clinical trials evaluating otoprotective benefits of nutrients should account for dietary quality, noise exposure history, and exercise habits as potential covariates that may influence the efficacy and effectiveness of test agents; pharmacokinetic measures are also encouraged.

Diet quality and hearing loss among middle-older aged adults in the USA: findings from National Health and Nutrition Examination Survey

OBJECTIVE

To examine the associations between overall diet quality and hearing function among middle-older aged adults in the USA.

DESIGN

Cross-sectional analysis. Diet quality was examined using the Mediterranean Diet Score (MDS), using data from a single 24 h dietary recall. Hearing function was objectively measured by audiometry assessments and hearing loss, including high- and low-frequency hearing loss, was defined as pure-tone averages at specific ranges of hearing frequencies >25 dB. Weighted logistic regression analyses were performed to examine the associations of MDS (scored 0-9, categorized at the median as ≤3 or >3) with hearing loss and high- and low-frequency hearing loss.

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.

Association of Nutritional Factors with Hearing Loss

Hearing loss (HL) is a major public health problem. Nutritional factors can affect a variety of diseases, such as HL, in humans. Thus far, several studies have evaluated the association between nutrition and hearing. These studies found that the incidence of HL was increased with the lack of single micro-nutrients such as vitamins A, B, C, D and E, and zinc, magnesium, selenium, iron and iodine. Higher carbohydrate, fat, and cholesterol intake, or lower protein intake, by individuals corresponded to poorer hearing status. However, higher consumption of polyunsaturated fatty acids corresponded to better hearing status of studied subjects. In addition to malnutrition, obesity was reported as a risk factor for HL. In studies of the relationship between middle ear infection and nutrition in children, it was reported that lack of vitamins A, C and E, and zinc and iron, resulted in poorer healing status due to vulnerability to infection. These studies indicate that various nutritional factors can affect hearing. Therefore, considering that multifactorial nutritional causes are responsible, in part, for HL, provision of proper guidelines for maintaining a proper nutritional status is expected to prevent some of the causes and burden of HL.

Dietary patterns and hearing loss in older men enrolled in the Caerphilly Study

The association between dietary patterns (DP) and prevalence of hearing loss in men enrolled in the Caerphilly Prospective Study was investigated. During 1979-1983, the study recruited 2512 men aged 45-59 years. At baseline, dietary data were collected using a semi-quantitative FFQ, and a 7-d weighed food intake (WI) in a 30 % subsample. Five years later, pure-tone unaided audiometric threshold was assessed at 0·5, 1, 2 and 4 kHz. Principal component analysis (PCA) identified three DP and multiple logistic and ordinal logistic regression models examined the association with hearing loss (defined as pure-tone average of frequencies 0·5, 1, 2 and 4 kHz &gt;25 dB). Traditional, healthy and high-sugar/low-alcohol DP were found with both FFQ and WI data. With the FFQ data, fully adjusted models demonstrated significant inverse association between the healthy DP and hearing loss both as a dichotomous variable (OR=0·83; 95 % CI 0·77, 0·90; P&lt;0·001) and as an ordinal variable (OR=0·87; 95 % CI 0·81, 0·94; P&lt;0·001). With the WI data, fully adjusted models showed a significant and inverse association between the healthy DP and hearing loss (OR=0·85; 95 % CI 0·73, 0·99; P&lt;0·03), and a significant association between the traditional DP (per fifth increase) and hearing loss both as a dichotomous variable (OR=1·18; 95 % CI 1·02, 1·35; P=0·02) and as an ordinal variable (OR=1·17; 95 % CI 1·03, 1·33; P=0·02). A healthy DP was significantly and inversely associated with hearing loss in older men. The role of diet in age-related hearing loss warrants further investigation.

Age-Related Hearing Loss Associations With Changes in Brain Morphology

Age-related hearing loss has been associated with varied auditory cortex morphology in human neuroimaging studies. These findings have suggested that peripheral auditory system declines cause changes in brain morphology but could also be due to latent variables that affect the auditory periphery and brain. The current longitudinal study was designed to evaluate these explanations for pure-tone threshold and brain morphology associations. Thirty adults (mean age at Time 1 = 64.12 ± 10.32 years) were studied at two time points (average duration between visits = 2.62 ± 0.81 years). Small- to medium-effect size associations were observed between high-frequency pure-tone thresholds and auditory cortex gray matter volume at each time point. Although there were significant longitudinal changes in low- and high-frequency hearing measures and brain morphology, those longitudinal changes were not significantly correlated across participants. High-frequency hearing measures at Time 1 were significantly related to more lateral ventricle expansion, such that participants with higher measures exhibited larger increases in ventricle size. This ventricle effect was statistically independent of high-frequency hearing associations with auditory cortex morphology. Together, these results indicate that there are at least two mechanisms for associations between age-related hearing loss and brain morphology. Potential explanations for a direct hearing loss effect on brain morphology, as well as latent variables that likely affect both the inner ear and brain, are discussed.

Interplay between Nutrition and Hearing Loss: State of Art

Hearing loss has been recently ranked as the fifth leading cause of years lived with disability, ahead of many other chronic diseases such as diabetes, dementia, or chronic obstructive pulmonary disease. Moreover, according to the World Health Organization, moderate-to-profound hearing loss affects about 466 million people worldwide. Its incidence varies in each population segment, affecting approximately 10% of children and increasing to 30% of the population over 65 years. However, hearing loss receives still very limited research funding and public awareness. This sensory impairment is caused by genetic and environmental factors, and among the latter, the nutritional status has acquired relevance due its association to hearing loss detected in recent epidemiological studies. Several experimental models have proved that the onset and progression of hearing loss are closely linked to the availability of nutrients and their metabolism. Here, we have reviewed studies focused on nutrient effects on auditory function. These studies support the potential of nutritional therapy for the protection against hearing loss progression, which is especially relevant to the aging process and related quality of life.

Progression of Hearing Loss in the Aging Population: Repeated Auditory Measurements in the Rotterdam Study

We quantified changes in the auditory acuity of 675 aging adults (mean age 71.1 years, 52.0% female, mean follow-up 4.4 years ± 0.2) of an ongoing cohort study with a pure-tone audiogram and a speech-in-noise test. Generalized estimating equation models were used to study the association between hearing loss and the progression with age, sex, education, cognition, BMI, blood pressure, having type 2 diabetes mellitus, cholesterol ratio, smoking and alcohol consumption. The mean progression of hearing loss was 0.29 and 1.35 dB/year (low and high frequencies). Progression of hearing loss was associated with baseline hearing thresholds. Besides, the presence of type 2 diabetes, smoking, age, sex and time were associated with worse hearing at baseline, but there was no statistical evidence that the tested determinants were associated with progression of hearing loss. This finding indicates that the 4-year progression of hearing loss in older adults in this study is not influenced by the measured determinants. More research with multiple follow-up rounds is desired.

Adherence to Healthful Dietary Patterns Is Associated with Lower Risk of Hearing Loss in Women

Background

Specific nutrients have been associated with hearing status, but associations between healthful dietary patterns and risk of hearing loss have not been prospectively evaluated.

Objective

We sought to prospectively examine the relations between adherence to the Alternate Mediterranean diet (AMED), the Dietary Approaches to Stop Hypertension (DASH), and the Alternative Healthy Eating Index-2010 (AHEI-2010), and risk of hearing loss.

Methods

We conducted a longitudinal cohort study (1991-2013) of 81,818 women in the Nurses' Health Study II, aged 27-44 y at baseline. We assessed diet every 4 y with the use of food frequency questionnaires and calculated AMED, DASH, and AHEI-2010 adherence scores. Baseline and updated information from validated biennial questionnaires was used in Cox proportional hazards regression models to examine independent associations between adherence scores and risk of self-reported moderate or worse hearing loss.

Results

During >1 million person-years of follow-up, 2306 cases of moderate or worse hearing loss were reported. Higher cumulative average AMED and DASH scores were significantly inversely associated with risk of hearing loss. For women with scores in the highest compared with the lowest quintile, the multivariable-adjusted relative risks (MVRRs) of hearing loss were 0.70 (95% CI: 0.60, 0.82) (P-trend <0.001) for AMED and 0.71 (95% CI: 0.61, 0.83) (P-trend <0.001) for DASH. Higher recent AHEI-2010 score was also associated with lower risk [MVRR = 0.79 (95% CI: 0.69, 0.91); P-trend <0.001]. Among participants with additional hearing-related information (n = 33,102), higher cumulative average adherence scores for all 3 dietary patterns were associated with lower risk; the MVRR was 0.63 (95% CI: 0.49, 0.81) for AMED, 0.64 (95% CI: 0.50, 0.83) for DASH, and 0.71 (95% CI: 0.56, 0.89) for AHEI-2010.

Conclusion

Adherence to healthful dietary patterns is associated with lower risk of hearing loss in women. Consuming a healthy diet may be helpful in reducing the risk of acquired hearing loss.

Relationship Between Objectively Measured Physical Activity, Cardiovascular Disease Biomarkers, and Hearing Sensitivity Using Data From the National Health and Nutrition Examination Survey 2003-2006

PURPOSE

Limited research has examined the interrelationships among cardiometabolic parameters, physical activity, and hearing function, which was this study's purpose.

METHOD

Data from the National Health and Nutrition Examination Survey (NHANES) 2003-2006 were used in the path analyses. Physical activity and hearing function were both objectively measured. Various cardiometabolic parameters were assessed from a blood sample. Adults 30-85 years (N = 1,070) constituted the analytic sample.

RESULTS

Physical activity was negatively associated with triglycerides (β = -0.11, p < .05) and insulin (β = -0.27, p < .05); triglycerides (β = 0.01, p < .05), and insulin (β = 0.05, p < .05) were positively associated with high-frequency pure-tone average (HPTA). The direct path from physical activity to HPTA was nonsignificant (β = 0.01, p = .99).

CONCLUSION

Physical activity was associated with select cardiovascular disease risk factors. Several cardiovascular disease risk factors were associated with hearing function.

Age-related hearing impairment and the triad of acquired hearing loss

Understanding underlying pathological mechanisms is prerequisite for a sensible design of protective therapies against hearing loss. The triad of age-related, noise-generated, and drug-induced hearing loss displays intriguing similarities in some cellular responses of cochlear sensory cells such as a potential involvement of reactive oxygen species (ROS) and apoptotic and necrotic cell death. On the other hand, detailed studies have revealed that molecular pathways are considerably complex and, importantly, it has become clear that pharmacological protection successful against one form of hearing loss will not necessarily protect against another. This review will summarize pathological and pathophysiological features of age-related hearing impairment (ARHI) in human and animal models and address selected aspects of the commonality (or lack thereof) of cellular responses in ARHI to drugs and noise.

Association of dietary factors with presence and severity of tinnitus in a middle-aged UK population

OBJECTIVE

The impact of dietary factors on tinnitus has received limited research attention, despite being a considerable concern among people with tinnitus and clinicians. The objective was to examine the link between dietary factors and presence and severity of tinnitus.

DESIGN

This study used the UK Biobank resource, a large cross-sectional study of adults aged 40-69. 171,722 eligible participants were asked questions specific to tinnitus (defined as noises such as ringing or buzzing in the head or ears). Dietary factors included portions of fruit and vegetables per day, weekly fish consumption (oily and non-oily), bread type, cups of caffeinated coffee per day, and avoidance of dairy, eggs, wheat and sugar. We controlled for lifestyle, noise exposure, hearing, personality and comorbidity factors.

RESULTS

Persistent tinnitus, defined as present at least a lot of the time, was elevated with increased: (i) fruit/vegetable intake (OR = 1.01 per portion/day), (ii) bread (wholemeal/wholegrain, OR = 1.07; other bread, 1.20) and (iii) dairy avoidance (OR = 1.27). Persistent tinnitus was reduced with: (i) fish consumption (non-oily, OR = 0.91; oily, 0.95), (ii) egg avoidance (OR = 0.87) and (iii) caffeinated coffee consumption (OR = 0.99 per cup/day). Reports of “bothersome” tinnitus (moderate-severe handicap) reduced with wholemeal/wholegrain bread intake (OR = 0.86) [corrected].Reports of less frequent transient tinnitus increased with dairy avoidance (OR = 1.18) and decreased with caffeinated coffee (OR = 0.98 per cup/day) and brown bread (OR = 0.94).

CONCLUSIONS

This is the first population study to report the association between dietary factors and tinnitus. Although individually dietary associations are mostly modest, particular changes in diet, such as switching between foodstuffs, may result in stronger associations. These findings offer insights into possible dietary associations with tinnitus, and this may be useful when discussing management options in combination with other lifestyle changes and therapies.

Associations between dietary quality, noise, and hearing: data from the National Health and Nutrition Examination Survey, 1999-2002

OBJECTIVE

A statistically significant relationship between dietary nutrient intake and threshold sensitivity at higher frequencies has been reported, but evidence conflicts across studies. Here, the potential interaction between noise and diet in their association to hearing was examined.

DESIGN

This cross-sectional analysis was based on Healthy Eating Index data and audiological threshold pure-tone averages for low (0.5 to 2 kHz) and high (3 to 8 kHz) frequencies.

STUDY SAMPLE

Data were drawn from the National Health and Nutrition Examination Survey, 1999-2002.

RESULTS

Controlling for age, sex, race/ethnicity, education, diabetes, hypertension, and smoking we found statistically significant relationships between dietary quality and high-frequency threshold sensitivity as well as noise exposure and high-frequency thresholds. In addition, there was a statistically significant interaction between dietary quality and reported noise exposure with respect to high-frequency threshold sensitivity in participants, where greater reported noise exposure and poorer diet were associated with poorer hearing (p's < 0.05).

CONCLUSIONS

The current findings support an association between healthier eating and better hearing at higher frequencies; the strength of this relationship varied as a function of participant noise history, with the most robust relationship in those that reported military service or firearm use.

Association between diet quality with concurrent vision and hearing impairment in older adults

OBJECTIVES

Published literature shows that individual nutrients could influence the risk of developing vision and hearing loss. There is, however, a lack of population-based data on the relationship between overall patterns of food intake and the presence of concurrent vision and hearing impairment. We aimed to assess the associations between diet quality with the prevalence and 5-year incidence of dual sensory impairment (DSI).

DESIGN

Cross-sectional and 5-year longitudinal analyses.

SETTING

Blue Mountains, Sydney, Australia.

PARTICIPANTS

2443 participants aged ≥50 from baseline were examined and followed over 5 years.

MEASUREMENTS

Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet score (TDS). Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average pure-tone air conduction threshold greater than 25 dB HL (500-4000 Hz, better ear).

RESULTS

After adjusting for age, sex, education, noise exposure, current smoking, and type 2 diabetes, participants in the lowest compared to the highest quintile of TDS had a 2-fold increased likelihood of having prevalent DSI, odds ratio, OR, 2.62 (95% confidence intervals, CI, 1.08-6.36), P-trend=0.04. Significant associations were not observed between TDS and the prevalence of having a single sensory impairment (vision or hearing loss). Baseline TDS was not significantly associated with the 5-year incidence of DSI. Adherence to dietary guidelines was associated with a reduced likelihood of having DSI in cross-sectional, but not in longitudinal analyses.

CONCLUSIONS

Further studies with adequate power are warranted to assess the prospective relationship between diet quality and DSI.

Healthy diets, healthy hearing: National Health and Nutrition Examination Survey, 1999-2002

OBJECTIVE

A significant relationship between dietary nutrient intake and susceptibility to acquired hearing loss is emerging. Variability in the outcomes across studies is likely related to differences in the specific metrics used to quantify nutrient intake and hearing status. Most studies have used single nutrient analysis. Although this analysis is valuable, interactions between nutrients are increasingly recognized and could modify modeling of single nutrient effects. Therefore, we examined the potential relationship between diet and hearing using a metric of overall dietary quality.

DESIGN

This cross-sectional analysis was based on healthy eating index data and audiological thresholds.

STUDY SAMPLE

Data for adults between the ages of 20 to 69 years of age were drawn from the National Health and Nutrition Examination Survey, 1999-2002.

RESULTS

Controlling for age, race/ethnicity, sex, education, diabetes, and noise exposure, we found a significant negative relationship (Wald F = 6.54, df = 4, 29; p ≤ 0.05) between dietary quality and thresholds at higher frequencies, where higher dietary quality was associated with lower hearing thresholds. There was no statistically significant relationship between dietary quality and threshold sensitivity at lower frequencies.

CONCLUSIONS

The current findings support an association between healthier eating and better high frequency thresholds in adults.

Dietary intake of cholesterol is positively associated and use of cholesterol-lowering medication is negatively associated with prevalent age-related hearing loss

We aimed to assess associations between dietary intake of fats (saturated and monounsaturated fats and cholesterol) and certain food groups (butter, margarine, and nuts) with the prevalence, incidence, and progression of age-related hearing loss. We also aimed to investigate the link between serum lipids and cholesterol-lowering medication (statins) and hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss. Hearing loss was measured in 2956 participants (aged ≥50 y) and was defined as the pure-tone average (PTA) of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level (PTA(0.5-4 kHz)). Dietary data were collected using a semiquantitative FFQ. After multivariable adjustment, the likelihood of prevalent hearing loss increased from the lowest (reference) to the highest quartile of dietary cholesterol intake (P-trend = 0.04). Among persons self-reporting statin use (n = 274), a 48% reduced odds of prevalent hearing loss was observed after multivariable adjustment [OR = 0.52 (95% CI = 0.29-0.93)]. Participants in the second and 3rd quartiles of dietary monounsaturated fat intake compared with those in the first quartile (reference) had a significantly reduced risk of hearing loss progression 5 y later [multivariable-adjusted OR = 0.39 (95% CI = 0.21-0.71)] and [OR = 0.51 (95% CI = 0.29-0.91)], respectively. Our results suggest that a diet high in cholesterol could have adverse influences on hearing, whereas treatment with statins and consumption of monounsaturated fats may have a beneficial influence.