The association between dietary acid load and odds of non-alcoholic fatty liver disease: A case-control study

Dietary acid load in health and disease

Maintaining an appropriate acid-base equilibrium is crucial for human health. A primary influencer of this equilibrium is diet, as foods are metabolized into non-volatile acids or bases. Dietary acid load (DAL) is a measure of the acid load derived from diet, taking into account both the potential renal acid load (PRAL) from food components like protein, potassium, phosphorus, calcium, and magnesium, and the organic acids from foods, which are metabolized to bicarbonate and thus have an alkalinizing effect. Current Western diets are characterized by a high DAL, due to large amounts of animal protein and processed foods. A chronic low-grade metabolic acidosis can occur following a Western diet and is associated with increased morbidity and mortality. Nutritional advice focusing on DAL, rather than macronutrients, is gaining rapid attention as it provides a more holistic approach to managing health. However, current evidence for the role of DAL is mainly associative, and underlying mechanisms are poorly understood. This review focusses on the role of DAL in multiple conditions such as obesity, cardiovascular health, impaired kidney function, and cancer.

Dietary acid load and cirrhosis-related mortality: a prospective cohort study

As a global health concern, cirrhosis contributes significantly to morbidity and mortality. This prospective cohort study aimed to investigate the association between dietary acid load (DAL) and cirrhosis-related mortality. Present study was conducted on 121 patients with newly diagnosed cirrhosis who were followed up for 48 months. Anthropometric measures, nutritional status and dietary intakes were assessed and DAL was estimated based on potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores. Crude and multivariable-adjusted hazard ratios (HR) with 95% confidence intervals (CI) were estimated using Cox proportional hazard analyses. Participants in the high PRAL and NEAP scores had significantly higher intakes of grains and lower intakes of fruits and vegetables. Also, the intake of dairy products and legumes, nuts and seeds decreased significantly with increasing NEAP score. After adjustment of all the confounders, the risk of mortality in the second and third tertiles of PRAL was 5.9 times and 10.97 higher than those in the first tertile, respectively (P trend: 0.006). Similarly, comparing the risk of mortality in the second and third tertiles with the first tertile of NEAP showed a 4.46-fold and 12.3-fold increased risk, respectively (P trend: 0.010). Our findings suggested that DAL was significantly associated with cirrhosis-related mortality and highlight the need for further research to understand the underlying mechanisms and establish optimal DAL levels in cirrhotic patients.

Association of Dietary Acid Load with Nonalcoholic Fatty Liver Disease and Advanced Liver Fibrosis in US Adults: Evidence from NHANES 1999-2018

Background

Evidence for an association between dietary acid load (DAL) and non-alcoholic fatty liver disease (NAFLD) is scarce and controversial. We aimed to address whether an association exists between DAL and NAFLD/advanced liver fibrosis (AHF) among US adults in a nationally representative study.

Methods

This was a cross-sectional study. We included adult participants from the National Health and Nutrition Examination Survey 1999-2018. Potential renal acid load (PRAL) and estimated net endogenous acid production (NEAP) was calculated from the literature and NAFLD/AHF was diagnosed by noninvasive markers. We comprehensively explored these relationships using multivariate adjusted regression models, restricted cubic spline, stratification analysis, and sensitivity analysis.

Results

We enrolled a total of 18,855 participants. All DAL metrics were positively and nonlinearly associated with NAFLD (all p-values < 0.0001), whereas NEAPF and NEAPR may be associated with AHF. In the stratified analysis, we found that the correlation between DAL and NAFLD exists in all ages and genders, but the effect of DAL seems to be more obvious in middle-aged, elderly and women. Similarly, we found that the effect of DAL on AHF was more significant in 45-60-year-olds and women. Sensitivity analyses revealed stability of all results.

Conclusion

DAL including PRAL and NEAP were positively associated with NAFLD in a large nationally representative cross-sectional study. NEAPF and NEAPR may be associated with increased odds of AHF. Adjustment for diet-dependent DAL requires age- and sex-specific strategies. Future prospective studies are needed to validate our findings.

International diet quality index and revised diet quality index relationship with non-alcoholic fatty liver disease: a case-control study

BACKGROUND/OBJECTIVES

Recent studies show the potential role of dietary quality and quantity in predicting the risk of chronic diseases, such as liver disease, therefore, in the present study, we aimed to assess the association of diet quality index International (DQI-I) and diet quality index revised (DQI-R) and their main components with the odds of non-alcoholic fatty liver disease (NAFLD) in adult populations.

METHODS

The current case-control study was conducted on 225 patients with NAFLD and 450 controls. Dietary intake was assessed using a validated 168-item food frequency questionnaire, and DQI-I and DQI-R were calculated in participants. Multi-variable logistic regression was used to examine the association of DQI-I and DQI-R and their components with the odds of NAFLD.

RESULTS

The mean (SD) age and BMI of participants (53% men) were 38.1 (8.8) years and 26.8 (4.3) kg/m2, respectively. In the final model, each one SD increment in the DQI-I score was associated with decreased odds of NAFLD (OR = 0.63; 95%CI = 0.40-0.98) (P = 0.040). Also, of DQI-I components, high adequacy score was related to lower odds of NAFLD (OR = 0.16; 95%CI = 0.06-0.40) (P < 0.001). Also, our findings showed that participants in the highest tertile of DQI-R score had lower odds of NAFLD compared to the lowest tertile of DQI-R (OR = 0.24; 95%CI = 0.10-0.53) (P < 0.001). Furthermore, of DQI-R components, high moderation score are linked to a lower risk of NAFLD (OR = 0.17;95%CI = 0.07-0.43) (P < 0.001).

CONCLUSION

Our findings suggested that greater adherence to diet with a higher score of DQI-I and DQI-R may be associated with lower odds of NAFLD.