For many years, it has been stated as settled science that Americans need to cut back their sodium intake from the current averages of about 3400 mg/day to less than  2400 mg sodium (about 1 teaspoon of table salt). The 2400 mg figure is endorsed by the National Academies, as described in the 164-page (we’re from the government and we’re here to help) booklet Dietary Guidelines for Americans published by USDA and HHS. The reason given is that supposedly there is a roughly linear relationship between salt intake and blood pressure, with higher blood pressure correlating to heart disease. The World Health Organization (WHO) recommends less than 2000 mg.

The dietary salt boat has been rocked in the past several years by studies claiming that cutting sodium below about 3400 mg does not help with heart disease (except for patients who already incline toward hypertension), and that cutting it much below 2400 mg is actually harmful.

The medical establishment has come out swinging to attack these newer studies. A 2018 article (Salt and heart disease: a second round of “bad science”? ) in the premier British medical journal The Lancet acknowledged this controversy:

2 years ago, Andrew Mente and colleagues, after studying more than 130000 people from 49 different countries, concluded that salt restriction reduced the risk of heart disease, stroke, or death only in patients who had high blood pressure, and that salt restriction could be harmful if salt intake became too low. The reaction of the scientific community was swift. “Disbelief” was voiced that “such bad science” should be published by The Lancet.  The American Heart Association (AHA) refuted the findings of the study, stating that they were not valid, despite the AHA for many years endorsing products that contain markedly more salt than it recommends as being “heart healthy”.

This article went on to note that, “with an average lifespan of 87·3 years, women in Hong Kong top life expectancy worldwide despite consuming on average 8–9 g of salt per day, more than twice the amount recommended by the AHA recommendation. A cursory look at 24 h urinary sodium excretion in 2010 and the 2012 UN healthy life expectancy at birth in 182 countries, ignoring potential confounders, such as gross domestic product, does not seem to indicate that salt intake, except possibly when very high, curtails lifespan.”

A more recent (2020) article by salt libertarians, Salt and cardiovascular disease: insufficient evidence to recommend low sodium intake, stated in its introduction:

In 2013, an independent review of the evidence by the National Academy of Medicine (NAM) concluded there to be insufficient evidence to support a recommendation of low sodium intake for cardiovascular prevention. However, in 2019, a re-constituted panel provided a strong recommendation for low sodium intake, despite the absence of any new evidence to support low sodium intake for cardiovascular prevention, and substantially more data, e.g. on 100 000 people from Prospective Urban Rural Epidemiology (PURE) study and 300 000 people from the UK-Biobank study, suggesting that the range of sodium intake between 2.3 and 4.6 g/day is more likely to be optimal.

… In this review, we examine whether the recommendation for low sodium intake, reached by current guideline panels, is supported by robust evidence. Our review provides a counterpoint to the current recommendation for low sodium intake. We suggest that a specific low sodium intake target (e.g. <2.3 g/day) for individuals may be unfeasible, have uncertain consequences for other dietary factors, and have unproven effectiveness in reducing cardiovascular disease. We contend that current evidence, despite methodological limitations, suggests that most of the world’s population consume a moderate range of dietary sodium (1–2 teaspoons of salt) that is not associated with increased cardiovascular risk, and that the risk of cardiovascular disease increases when sodium intakes exceed 5 g/day.

The keepers of orthodoxy fired back the following year in an article with an ugly title Sodium and Health: Old Myths and a Controversy Based on Denial  and making ugly accusations:

Some researchers have propagated a myth that reducing sodium does not consistently reduce CVD but rather that lower sodium might increase the risk of CVD. These claims are not well-founded and support some food and beverage industry’s vested interests in the use of excessive amounts of salt to preserve food, enhance taste, and increase thirst. Nevertheless, some researchers, often with funding from the food industry, continue to publish such claims without addressing the numerous objections.

Ouch.

I don’t have the expertise to dig down and make a ruling on who is right here. But I do feel better about eating my tasty salty chips, knowing I have at least some scholarly support for my habit.