Reduced dietary acid load in U.S. vegetarian adults: Results from the National Health and Nutrition Examination Survey

Abstract

Dietary acid load (DAL) is an important determinant of systemic pH and acid–base homeostasis. Diets abundant in acidogenic foods, such as meat and meat products, induce a low‐grade metabolic acidosis state that has been associated with cardiovascular disease, type‐2‐diabetes, and an increased cancer risk. Fruits and vegetables have alkalizing properties and beneficially affect DAL. It has thus been suggested that a plant‐based diet (restricting or excluding animal products) may be a powerful tool in reducing DAL; yet studies in that particular field are scarce. To explore these associations in greater detail, we examined DAL in self‐identified vegetarians from the United States National Health and Nutrition Examination Survey (2007–2010). We compared dietary intake and two widely used markers of DAL (PRAL (potential renal acid load) and NEAP (net endogenous acid production; NEAPF and NEAPR)) among 8,398 nonvegetarians and 191 lacto‐ovo‐vegetarians with reliable dietary intake aged 18 years or older. Vegetarians had a more favorable body mass index and consumed fewer calories (1862.31 kcal/d) than nonvegetarians (2041.12 kcal/d). Vegetarians consumed fewer protein (34.17 g/1000 kcal) and phosphorus compared to nonvegetarians (39.50 g of protein/1000 kcal) but had a higher intake of magnesium and potassium. Nonvegetarians exhibited higher median DAL scores (PRAL: 11.90 mEq/d, NEAPF: 53.59 mEq/d, NEAPR: 55.67 mEq/d) than vegetarians (PRAL: −0.44 mEq/d, NEAPF: 39.60 mEq/d, NEAPR: 41.30 mEq/d). Vegetarians had more favorable DAL scores compared to nonvegetarians in this descriptive epidemiologic study. Future (interventional) trials are warranted to examine the varying acid load in different plant‐based dietary patterns.

Dietary Acid Load in Gluten-Free Diets: Results from a Cross-Sectional Study

“…Notably, there was an energy difference of almost 300 kcal/d between both groups. Total energy intake has been positively associated with PRAL scores in numerous studies and could also contribute to our findings [ 15 , 16 ].…”

“…The employed methods for DAL estimations have been discussed elsewhere in detail [ 16 ]. In brief, we used 3 established formulas to calculate DAL from daily nutrient intake: PRAL R (potential renal acid load—based on the Remer formula), NEAP R (net endogenous acid production based on the Remer formula) and NEAP F (net endogenous acid production based on the Frassetto formula).…”

“…However, the authors neither reported total energy intake nor protein intake [ 13 ]. Both are important determinants of DAL and necessary to understand the effects of a particular diet on acid–base homeostasis [ 14 , 15 , 16 ]. Replacing cereals with other cereals per se does hypothetically not affect DAL ( Table 1 ).…”

Observational and clinical evidence that plant-based nutrition reduces dietary acid load

“…Other diets, such as the DASH diet (Dietary Approaches to Stop Hypertension) resulted in substantially lower PRAL sums (about 11 mEq/d). PBDs are characterised by even lower PRAL sums (12) . The potential DAL-lowering mechanism of PBDs is discussed in detail hereafter.…”

“…We identified four observational studies investigating DAL scores in plant-based individuals (12,23,133,134) . Three studies investigated lacto-ovo-vegetarians (12,133,134) and two studies also investigated vegans (23,134) . The study characteristics may be obtained in a chronological order from Table 4.…”