Thanks for the tag, Mathias and Spencer!

Hi Oscar, CEARCH recently put out a report on hypertension as a cause area: https://forum.effectivealtruism.org/posts/k7NjuGEKdRSrrJHmZ/deep-report-on-hypertension 

(1) TLDR: We expect advocacy for top sodium control policies (particularly regulating food manufacturers to reduce the sodium content on processed food), so as to reduce the disease burden of hypertension/high blood pressure, to be at least 10x GiveWell cost-effectiveness.

(2) The scientific evidence on more salt = worse health outcomes (heart attacks, strokes etc) is rock solid. There was a controversy some years back on the "J-Curve" hypothesis, which was the idea that at low levels of sodium consumption, maybe it's bad to further reduce sodium intake because that actually worsens health outcomes (hence a J-curve with sodium consumption on the X-axis and adverse health events on the Y-axis). However, the current scientific consensus is that the initial studies purportedly showing this were faulty, with poor methodology (particularly in relying on imperfect measures of sodium levels, rather than like 24-hour urine samples). All the meta-analysis we've read in full (e.g. Aburto et al, Ettehad et al, Strazzullo et al) or checked the abstracts of basically back the idea of a sodium-blood pressure-cardiovascular disease relationship.

(3) On potassium replacement - it's definitely promising (in fact, since writing the report, I have been persuaded to use salt with like 33% potassium chloride when cooking). The issue is cost - it's just more expensive, and it's not as if you can force consumers to pay more. Which brings us back to the need for regulatory interventions (e.g. aforementioned reformulation of food) or fiscal interventions (e.g. taxing salt), paired with consumer education (e.g. nutrition labelling and mass media campaigns) and  just governments changing the menus in public schools, hospitals and workplaces.