Cardiovascular benefits associated with higher dietary K+vs. lower dietary Na+: evidence from population and mechanistic studies.
The World Health Organization ranks hypertension the leading global risk factor for disease, specifically, cardiovascular disease. Blood pressure (BP) is higher in Westernized populations consuming Na+-rich processed foods than in isolated societies consuming K+-rich natural foods. Evidence suggests that lowering dietary Na+is particularly beneficial in hypertensive individuals who consume a high-Na+diet. Nonetheless, numerous population studies demonstrate a relationship between higher dietary K+, estimated from urinary excretion or dietary recall, and lower BP, regardless of Na+intake. Interventional studies with K+supplementation suggest that it provides a direct benefit; K+may also be a marker for other beneficial components of a "natural" diet. Recent studies in rodent models indicate mechanisms for the K+benefit: the distal tubule Na+-Cl-cotransporter (NCC) controls Na+delivery downstream to the collecting duct, where Na+reabsorbed by epithelial Na+channels drives K+secretion and excretion through K+channels in the same region. High dietary K+provokes a decrease in NCC activity to drive more K+secretion (and Na+excretion, analogous to the actions of a thiazide diuretic) whether Na+intake is high or low; low dietary K+provokes an increase in NCC activity and Na+retention, also independent of dietary Na+Together, the findings suggest that public health efforts directed toward increasing consumption of K+-rich natural foods would reduce BP and, thus, cardiovascular and kidney disease.
Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California mcdonoug@usc.edu.
Alicia A
AA
McDonough
Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California.
Luciana C
LC
Veiras
Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California.
Claire A
CA
Guevara
Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California.
Donna L
DL
Ralph
D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D017419:Potassium, Dietary; D012982:Sodium, Dietary
D017419:Potassium, Dietary; D012982:Sodium, Dietary
ENaC; NCC; dietary potassium; dietary sodium; hypertension