Urinary Response to Consuming Plant-Based Meat Alternatives in Persons with Normal Kidney Function: The SWAP-MEAT Pilot Trial.

Background: Consuming excess animal meat may exacerbate kidney disorders, such as urinary stone disease and CKD. Plant-based meat alternatives imitate animal meat and replace animal with vegetable protein, but it is unclear whether eating plant-meat confers similar health benefits as eating whole vegetables. We hypothesized that eating plant-meat when compared with animal meat decreases dietary acid load but increases dietary phosphorus and nitrogen.

Methods: The Study With Appetizing Plantfood—Meat Eating Alternatives Trial was a randomized 8-week, crossover trial (NCT03718988) of participants consuming ≥2 servings/d of either plant-meat or animal meat for each 8-week phase. We measured urine sulfate, ammonium, pH, phosphorus, urea nitrogen (UUN), citrate, and creatinine concentrations and serum creatinine and bicarbonate concentrations from stored participant samples from each phase.

Results: At a single site, we enrolled 36 generally healthy participants (mean±SD age 50.2±13.8 years, 67% women, and 69% White). Eating the plant-meat diet versus eating the animal meat diet was associated with lower mean concentration of urine sulfate (−6.7 mEq/L; 95% confidence interval [CI], −11.0 to −2.4), urine ammonium (−4.2 mmol/L; 95% CI, −8.2 to −0.1), urine phosphorus (−9.0 mg/dl; 95% CI, −17.5 to −0.5), and UUN (−124.8 mg/dl; 95% CI, −226.9 to −22.6). Eating plant-meat compared with eating animal meat was associated with higher mean urine pH (+0.3 units; 95% CI, 0.2 to 0.5) and mean urine citrate/creatinine ratio (+111.65; 95% CI, 52.69 to 170.60). After participants consumed a plant-meat diet compared with when they consumed an animal meat diet, mean serum creatinine concentration was lower (−0.07 mg/dl, 95% CI, −0.10 to −0.04), whereas mean serum bicarbonate concentration was not different.

Conclusions: Eating plant-based meat products, compared with eating animal meat, was associated with lower urinary excretion of sulfate, ammonium, phosphorus, and UUN and higher urinary excretion of citrate. Our findings provide rationale for examining whether plant-based meat will benefit patients with kidney disease.