The WHO’s (mis)guidance on sodium

From the desk of
Robb Wolf
ScienceThe WHO’s (mis)guidance on sodium

The World Health Organization (WHO) recently re-provoked the war on salt. In a 99-page report, they claim that too much sodium is responsible for nearly 2 million deaths per year. They’ve concluded that capping sodium intake at 2 grams per day reduces blood pressure, improves heart health, and could save 7 million lives around the world by 2030.

The WHO’s claims, supporting data, and broad-sweeping recommendations are irresponsible—dangerous, even. For starters, their limit is way too low, especially for active people. 2 grams of sodium per day would spell headaches, muscle cramps, and brain fog for just about anybody following a moderate workout regimen—far be it from promoting a healthy heart, brain, or bones.

And the 7 million saved lives? This figure comes from cherry-picked correlations and non-peer-reviewed modeling that uses funky assumptions, including that most of the world has high blood pressure. I’ll dive into this and other fallacies later.

For now, simply recognize that a blanket restriction on an essential mineral is a bad idea. Yes, it’s possible to overdo salt (as with anything). But the biological sweet spot for sodium is at least double what the WHO recommends.

Don’t take my word for it here, though. Let’s first address the report and review the data. Then, I’ll share some solid research that shows how sodium actually relates to blood pressure, heart health, and mortality.

The New WHO Guidance on Sodium

The WHO’s 2023 report urges governments worldwide to reduce their constituents’ sodium intake by:

  • Reformulating foods to contain less sodium 
  • Highlighting low-sodium content in packaging
  • Limiting sodium-rich foods in public institutions, such as in hospitals, schools, and government buildings
  • Launching mass media campaigns against salt

So that’s what the report advises, but how do they justify these policy recommendations? 

4 Problems With the WHO Report

After reading the full WHO report, I have a minor headache but I also understand where its analysis and recommendations went wrong. I hope you’re wearing long sleeves because we’re about to get into the weeds – here’s 4 areas where the report’s analysis and recommendations went wrong.

#1: The central claims aren’t supported by peer-reviewed sources

Peer review is a foundational self-regulation mechanism for scientific papers. When other scientists have to sign off on findings, it (in theory, although not always in practice) helps prevent the spread of spurious data.

Early on, the report cites that 1.89 million deaths per year are linked to excess sodium intake. Unfortunately, the reference for this claim isn’t a peer-reviewed source, but rather an independent research organization called the Institute for Health Metrics and Evaluation. 

The WHO’s splashiest claim—that its sodium policies may save over 2 million deaths by 2025 and 7 million by 2030—also comes from a non-peer-reviewed source. That source is a WHO-developed model called NCDprime.

#2: The model is skewed toward those with high blood pressure

The WHO model has many squirrely assumptions. Here is one such chain of logic articulated on page 17 of the report:

  1. WHO policies will lead to a significant reduction in sodium intake (measured by sodium excretion) globally
  2. This sodium reduction will translate to a 5.56 mmHg average reduction in systolic blood pressure 
  3. This reduction in blood pressure will save millions of lives globally

For now, let’s focus on #2, the heart of the argument. This claim originates from a 2021 review of 85 sodium and blood pressure studies. Of these 85 studies:

  • 65 studies were exclusively on hypertensives (people with high blood pressure)
  • 11 studies were exclusively on normotensives (people with normal blood pressure)
  • 9 studies included both hypertensives and normotensives

This reveals a fundamental flaw in the claim that people would realize an average reduction in systolic blood pressure of 5.56 mmHg. One peer-reviewed estimate suggests that just 31.1% of adults had high blood pressure as of 2010. But the review chosen by the WHO mostly examined hypertensives, and so their data engulfed the data on normotensives. This is important because the data on normotensives indicated sodium restriction has very little effect on blood pressure. It’s hypertensives who see a drop in blood pressure with sodium restriction.

Why? Many hypertensives tend to be salt sensitive due to underlying metabolic issues. So I’ll concede that for these folks, it makes sense to moderate sodium intake while they work on improving their metabolic health. But a blanket recommendation to restrict sodium intake is irresponsible. And even in those that are hypertensive, we see strong clinical data to support higher levels of sodium intake than the WHO recommendation.

#3: Sodium intake data are unreliable

In the report, the authors admit “there is no comprehensive reporting of population sodium intake.” Much of the data comes from notoriously unreliable dietary surveys, and many countries lack this data to begin with. Without a reliable starting point, how can we talk about the effects of reducing global sodium intake?

#4: The report excludes data that doesn’t suit its purpose

The WHO report is an exhibition in cherry picking, omitting tons of evidence that show 2 grams of sodium per day isn’t optimal for heart health and longevity – and often even much worse. A global health authority should be more forthcoming than that.

Unlike the WHO, I’ll address both sides’ data. First, we’ll explore the genesis of the anti-salt movement. Then we’ll examine a few peer-reviewed papers the WHO omitted.

Is Salt Bad for Blood Pressure?

For context, the report pegs our current average daily sodium intake at 4.3 grams. So when the WHO recommends capping it at 2 grams, they’re trying to cut our sodium intake by more than half. Why? It’s all in the name of blood pressure, and this has quite a misguided story behind it.

This anti-salt movement originated from Lewis Dahl’s research in the 1960s. Dahl showed that salt sensitivity was a genetic trait by breeding salt-sensitive rats. Big surprise, injecting megadoses of sodium into rats with a salt-sensitive lineage significantly increased their blood pressure. This says nothing about how reasonable sodium intake affects human blood pressure, but nobody seemed to care. Fast forward two decades, and the 1980 US Dietary Guidelines officially admonished the public to avoid salt.

The bulk of the scientific data suggests otherwise. Consider the following:

  • The INTERSALT Study (1988) found ZERO correlation between salt consumption and high blood pressure in 10,000 people across 48 global populations.
  • A meta-analysis (2014) shows that sodium intakes fewer than 2.6 grams per day were associated with increased cardiovascular disease events and all-cause mortality, compared to intakes of 2.6–5 grams (PMID: 24651634).
  • The Framingham Offspring Study (2017) found that folks without hypertension had HIGHER blood pressure on low sodium diets (under 2.5 grams per day) than those exceeding that amount.
  • A Cochrane Collaboration Review (2020) found that low-salt diets correlated with a measly 0.4 mmHg reduction in mean arterial pressure in white populations, with scant evidence that other ethnicities fare better. Hypertensive white people, however, showed an average drop of about 4 mmHg after salt restriction. This drop is in line with another source from earlier and my stance on salt sensitivity. But here’s the take-home point: The authors of the Cochrane review concluded that the numerous adverse side effects of salt restriction were “more consistent” than the effects on blood pressure.

If moderate sodium intake—over 2.5 grams and within reason—caused hypertension in most people most of the time, it would appear in the INTERSALT, Cochrane, and Framingham results, but it simply doesn’t. The theory that sodium restriction is a surefire way to reduce blood pressure is flawed.

The Latest Science on Sodium, Heart Health, and Mortality

Irrespective of blood pressure, does sodium restriction result in fewer heart attacks, strokes, and death? A 2018 review in the Journal of American Medicine Association (JAMA) concluded that “Despite broad advocacy, uncertainty about the robustness of advice to reduce salt intake in patients with heart failure remains.”

Beyond that, sodium restriction appears to be—not just inconsequential—but dangerous for heart health. Here are two reputable studies that back that up:

  1. A 2011 JAMA study found that people limiting sodium to 3 grams per day had MORE heart attacks and strokes than those consuming 4–6 grams per day.
  2. A 2014 meta-analysis tells a similar story: Mortality and cardiovascular events were HIGHER in folks consuming less than 2.6 grams of sodium per day vs. intakes between 2.6–5 grams per day.

In other words, the WHO’s recommended daily sodium intake is likely less than the ideal range for optimal heart health.

As to why low-sodium diets are bad for your health, read on.

The Dangers of Sodium Restriction

Sodium isn’t a toxin. It’s an essential nutrient for hydration, performance, and energy. When you restrict dietary sodium, your body enters a sodium-retention mode whereby hormones—aldosterone, renin, and angiotensin—spike to help your kidneys retain sodium. The problem? The hormones also raise your blood pressure. This hypertensive action likely explains the increased blood pressures at lower salt intakes in the Framingham data.

Other side effects of low-sodium diets can be subtle. Brain fog, lethargy, irritability, weakness, muscle cramps, and headaches all have a variety of causes. Sodium deficiency is commonly the culprit, but thanks to the war on salt it’s rarely ever a suspect. And when we combine salt restriction with excessive fluid intake (that health-conscious person lugging around a gallon of water, for instance), we have a recipe for a life-threatening condition of low blood sodium: hyponatremia.

Another problem with low-salt diets? Your body will break down bone to maintain sodium levels in the blood. This can even occur at daily sodium intakes of 3 grams in an average-weight adult—a full gram more than the WHO recommendation! Your body would rather have osteoporosis than low blood sodium. I would rather have neither.

Based on the data I’ve been summarizing—and my personal experience speaking with thousands of health-conscious people—the sweet spot is between 4 and 6 grams of sodium per day. And that’s just a baseline. If you’re active, sweaty, eat a low-carb diet, practice intermittent fasting, or some combination of these factors, you may need much more!

Salt Isn’t the Problem – It’s the Modern Diet

The WHO is about as close to nailing sodium guidance as I am to landing a triple axel. Today, we’ve sampled enough scientific literature to make that clear. But why do some data—cherry-picked by the WHO—correlate high-sodium diets with health problems?

It’s the same reason I can claim that short people can’t read well. Three-foot tall toddlers may not be able to read novels, but height is not the causative factor. Age is.

Similarly, sodium isn’t the causative factor in many health studies. Yes, the modern diet is salty, but it’s also sugary and hyperpalatable. People who eat an ultra-processed diet full of packaged foods and refined sugar tend to consume the most sodium. It’s no secret that overeating refined foods leads to insulin resistance, diabetes, high blood pressure, obesity, and many other health issues that increase cardiovascular mortality.

If we want to save lives, we should spare the energy spent scraping together a 99-page compendium against an essential nutrient that most healthy people need more of, not less. That effort, teamwork, and money would be much more wisely spent on a campaign against the sugary modern diet. The solution is simple: celebrate nutritious whole foods, make them accessible, and promote a healthy weight and metabolism.

That’s my take on the new WHO report. I hope you find it useful as you navigate the bizarre world of public health recommendations.

Comments are closed.