Body Fluid pH Balance in Metabolic Health and Possible Benefits of Dietary Alkaline Foods

Living cells have several mechanisms to avoid acidic conditions created by excess protons. The protons are extruded to the extracellular space via the plasma membrane by various types of transporters such as the Na + /H + exchanger and monocarboxylate transporters, which hereby contribute to the exclusion of protons in the cells of metabolic tissues including the liver, skeletal muscle, and adipose tissue. Disturbances in the functioning of the transporters cause abnormal intracellular fluid pH of the cells and dysfunction of metabolic homeostasis, leading to the development of metabolic diseases and a decrease in physical fitness level. In addition to the intracellular fluid pH regulation, growing evidence shows that the fluid pH in the interstitial space around metabolic tissues is easily reduced due to weaker pH buffering capacity than that in the cytosol and blood circulation. Therefore, pH reduction in the interstitial fluid may cause the onset of metabolic dysfunction. In contrast, several dietary foods have direct and indirect benefits in maintaining the interstitial fluid pH to the normal range by improving buffering capacities, suppressing proton production, and activating proton transporters, which strengthen the effect of appropriate diet on metabolic health.