A Vegan Diet Is Associated with a Significant Reduction in Dietary Acid Load: Post Hoc Analysis of a Randomized Controlled Trial in Healthy Individuals.

Alexander Müller, Amy Marisa Zimmermann-Klemd, Ann-Kathrin Lederer, Luciana Hannibal, Stefanie Kowarschik, Roman Huber, Maximilian Andreas Storz

Journal: International journal of environmental research and public health 2021;18(19):9998

PMID: 34639299

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Plain Language Summary

Diets high in meat and cheese, which are acidogenic and low in fruits and vegetables, which are alkalising, increase the dietary acid load (DAL) of the diet. Diets with a high DAL have been associated with poor health outcomes and the development of heart disease and type 2 diabetes. Plant-based diets have been associated with a lower DAL, however very little research exists on this. Individuals following a vegan diet have been shown in previous studies to have a reduced DAL, however it is unclear whether this was due to a reduced calorie intake or because of the diet composition. This post-hoc study aimed to investigate this and determine whether eating a vegan diet for 4-weeks reduced DAL and how this compares to 4-weeks of a diet rich in meat. The results showed that after 3-weeks, the vegan diet significantly reduced the DAL compared to the meat-rich diet, which increased the DAL. Interestingly all the participants in this study were put on the same balanced diet for 7 days prior to commencing the trial, reducing the chance that results would be affected by a prior diet. It was concluded that a vegan diet as opposed to a meat-rich diet may be of benefit to health outcomes through lowering DAL. This study could be used by healthcare professionals to understand that a balanced vegan diet may be of benefit to those who have heart disease and/or type 2 diabetes. However as this trial did not measure indicators of type 2 diabetes or heart disease, these associations are speculative.

Abstract

The composition of diet strongly affects acid-base homeostasis. Western diets abundant in acidogenic foods (meat and cheese) and deficient in alkalizing foods (fruits and vegetables) increase dietary acid load (DAL). A high DAL has been associated with numerous health repercussions, including cardiovascular disease and type-2-diabetes. Plant-based diets have been associated with a lower DAL; however, the number of trials exploring this association is limited. This randomized-controlled trial sought to examine whether an isocaloric vegan diet lowers DAL as compared to a meat-rich diet. Forty-five omnivorous individuals were randomly assigned to a vegan diet ( = 23) or a meat-rich diet ( = 22) for 4 weeks. DAL was determined using potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores at baseline and after 3 and 4 weeks, respectively. After 3 weeks, median PRAL (-23.57 (23.87)) and mean NEAP (12.85 ± 19.71) scores were significantly lower in the vegan group than in the meat-rich group (PRAL: 18.78 (21.04) and NEAP: 60.93 ± 15.51, respectively). Effects were mediated by a lower phosphorus and protein intake in the vegan group. Our study suggests that a vegan diet is a potential means to reduce DAL, whereas a meat-rich diet substantially increases the DAL burden.

Address: Centre for Complementary Medicine, Department of Internal Medicine II, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany.; Medical Center, Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany.

DOI: 10.3390/ijerph18199998