Macroalgae as Alkalizing Marine Drugs with a Low Potential Renal Acid Load

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base perspective. Their unique biochemical composition suggests a low potential renal acid load (PRAL), which is a commonly used estimate for the amount of acid or base a certain food produces in humans. Here, we analyzed the PRAL value of n = 106 macroalgae. Results suggested a strong alkalizing potential, with a mean PRAL value of −86.76 mEq/100 g. The lowest PRAL values were found for Laminaria ochroleuca (−286.78 mEq/100 g), Gelidium micropterum (−268.46 mEq/100 g), and Palmaria palmata (−259.16 mEq/100 g). We observed a strong inverse relationship of PRAL with algae’s potassium content (Spearman’s rho = −0.79, p < 0.001) and a moderate relationship with algae’s calcium content (Spearmen’s rho: −0.34, p < 0.001). Our data point at a potential role for several macroalgae as potent alkalizing marine drugs and suggest that a 10 g edible portion of some algae alone could contribute to a substantial PRAL reduction of up to −28.68 mEq. This might be of particular importance for individuals who benefit from a more alkaline diet and warrants further investigation in future studies.