Associations between dietary indices and hearing status among middle-older aged adults - results from the Baltimore Longitudinal Study of Aging

BACKGROUND

Hearing loss, a public health issue in older populations, is closely related to functional decline.

OBJECTIVE

To investigate the longitudinal associations between 4 dietary indices and hearing status.

METHODS

Data from the Baltimore Longitudinal Study of Aging were used and included 882 participants ≥45 y of age. Dietary intake was assessed using a validated food frequency questionnaire, and 4 dietary scores (Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay diet [MIND], Mediterranean style diet score [MDS], Alternative Healthy Eating Index [AHEI], and Healthy Eating Index [HEI]) were calculated as averages over time. Hearing status was examined using pure-tone audiometry, and pure-tone average (PTA) of hearing thresholds were calculated at speech-level (PTA(500, 1000, 2000, 4000 Hz)), low (PTA(500, 1000 Hz)), and high (PTA(4000, 8000 Hz)) frequencies, with lower thresholds indicating better hearing. Multivariable linear mixed-effect models were used to examine associations between dietary indices and hearing threshold change over time adjusted for confounders.

RESULTS

At baseline, the mean age of participants was 67 y and 55% were female. Over a median of 8 y of follow-up, MDS ≥7 was associated with 3.5 (95% CI: -6.5, -0.4) and 5.0 (95% CI: -9.1, -1.0) dB lower PTA(500, 1000, 2000, 4000 Hz) and PTA(4000, 8000 Hz), respectively, compared with MDS ≤3; the highest tertile of the AHEI was associated with 2.3 (95% CI: -4.6, -0.1) and 5.0 (95% CI: -8.0, -2.0) dB lower PTA(500, 1000, 2000, 4000 Hz) and PTA(4000, 8000 Hz); and each standard deviation increment in HEI was associated with 1.6 dB (95% CI: -2.7, -0.6), 1.1 dB (95% CI: -2.1, -0.1), and 2.1 dB (95% CI: -3.5, -0.6) lower PTA(500, 1000, 2000, 4000 Hz), PTA(500, 1000 Hz), and PTA(4000, 8000 Hz), respectively.

CONCLUSIONS

Adherence to healthy dietary patterns was associated with better hearing status, with stronger associations at high frequencies. Am J Clin Nutr 20xx;x:xx.

Associations of dietary patterns with risk of incident atrial fibrillation in the REasons for Geographic And Racial Differences in Stroke (REGARDS)

BACKGROUND

We examined whether the risk of incident atrial fibrillation (AF) in a large, biracial, prospective cohort is lower in participants who adhere to heart-healthy dietary patterns and higher in participants who adhere to less heart-healthy diets.

METHODS

Between 2003 and 2007, the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort study enrolled 30,239 Black and White Americans aged 45 years or older. Dietary patterns (convenience, plant-based, sweets, Southern, and alcohol and salads) and the Mediterranean diet score (MDS) were derived based on food frequency questionnaire data. The primary outcome was incident AF at the follow-up visit 2013-2016, defined by either electrocardiogram or self-reported medical history of a physician diagnosis.

RESULTS

This study included 8977 participants (mean age 63 ± 8.3 years; 56% women; 30% Black) free of AF at baseline who completed the follow-up exam an average of 9.4 years later. A total of 782 incident AF cases were detected. In multivariable logistic regression analyses, neither the MDS score (odds ratio (OR) per SD increment = 1.03; 95% confidence interval (CI) 0.95-1.11) or the plant-based dietary pattern (OR per SD increment = 1.03; 95% CI 0.94-1.12) were associated with AF risk. Additionally, an increased AF risk was not associated with any of the less-healthy dietary patterns.

CONCLUSIONS

While specific dietary patterns have been associated with AF risk factors, our findings fail to show an association between diet patterns and AF development.

A pilot study to investigate if New Zealand men with prostate cancer benefit from a Mediterranean-style diet

Carcinoma of the prostate is the most commonly diagnosed malignancy and the third leading cause of mortality in New Zealand men, making it a significant health issue in this country. Global distribution patterns suggest that diet and lifestyle factors may be linked to the development and progression of this cancer. Twenty men with diagnosed prostate cancer adhered to a Mediterranean diet, with specific adaptations, for three months. Prostate-specific antigen, C-reactive protein and DNA damage were evaluated at baseline and after three months of following the diet. Dietary data were collated from diet diaries and an adaptation of a validated Mediterranean diet questionnaire. A significant reduction in DNA damage compared to baseline was apparent, with particular benefit noted for overall adherence to the diet (p = 0.013), increased intake of folate (p = 0.023), vitamin C (p = 0.007), legumes (p = 0.004) and green tea (p = 0.002). Higher intakes of red meat and dairy products were inversely associated with DNA damage (p = 0.003 and p = 0.008 respectively). The results from this small feasibility study suggest that a high-antioxidant diet, modelled on Mediterranean traditions, may be of benefit for men with prostate cancer. Protection against DNA damage appears to be associated with the diet implemented, ostensibly due to reduction in reactive oxidant species. These findings warrant further exploration in a longer trial, with a larger cohort.