Here’s one, full text.
Article Highlights
Over several million years, physiology and metabolism of humans evolved to retain Na+ and excrete K+ in response to a diet that was low in Na+ and high in K+. With the onset of agriculture and industrialization, there has been a precipitous drop in dietary K+ consumption and an equal rise in dietary salt consumption, contributing to disease onset. This is further supported by the fact that the newest Dietary Guidelines for Americans have listed K+ as a “nutrient of public health concern” because of its inadequate consumption. Low K+ intake is then implicated in various chronic diseases including hypertension, cardiovascular disease, osteoporosis, and nephrolithiasis.
The authors contend:
… The changes in K+ and Na+ intake over time reflect a shift from traditional plant-based diets high in K+ and low in Na+ (characterized by fruits, leafy greens, roots, and tubers) to processed foods high in Na+ and low in K+. The transition to processed foods began approximately 10,000 years ago with the onset of agriculture.
I think they are incorrect about the sources of potassium… But, however we got the high potassium and low sodium, they discuss the physiology of why they think humans evolved in a potassium-high and sodium-low environment. And “…our current diet represents a mismatch between what our body has the capability to metabolize and what we are actually consuming”. The authors provide a very detailed physiological discussion to support their contention. Worth the long read.
@PaulL
Conclusion
There are abundant data suggesting that ingestion of K+-rich foods is beneficial and may reduce the incidence of stroke, hypertension, nephrolithiasis, and osteoporosis. The data on dietary consumption indicate that Western diets are high in processed foods, high in Na+ content, and low in K+. The kidney is designed to handle significantly higher K+ loads than are currently consumed in our diet. Furthermore, patients who could most benefit from increasing their intake of K+-rich foods are the very same patients who are unable to do so because of reductions in renal function.
One of their sources is the following. Unfortunately full text available to subscribers only:
Another source, again unfortunately behind an subscriber wall:
…The genetically conditioned nutritional requirements of human beings established themselves over millions of years in which ancestral hominins, living as hunter-gatherers, ate a diet markedly different from that of agriculturally dependent contemporary human beings. In that context, we sought to quantify the ancestral-contemporary dietary difference with respect to the supply of one of the body’s major mineral nutrients: potassium. In 159 retrojected Stone Age diets, human potassium intake averaged 400 ± 125 mEq/d, which exceeds current and recommended intakes by more than a factor of 4. We accounted for the transition to the relatively potassium-poor modern diet by the fact that the modern diet has substantially replaced Stone Age amounts of potassium-rich plant foods (especially fruits, leafy greens, vegetable fruits, roots, and tubers), with energy-dense nutrient-poor foods (separated fats, oils, refined sugars, and refined grains), and with potassium-poor energy-rich plant foods (especially cereal grains) introduced by agriculture (circa 10,000 years ago).
Again, I disagree with the source of potassium, but otherwise I find the argument persuasive. It seems logical to me that so many ailments/diseases being related to potassium deficiency (and/or elevated sodium) that evolution in a period of potassium abundance and sodium dearth makes sense.