The salt myth: why healthy eaters often need more sodium, not less

"Reduce your salt intake." You've heard it from your doctor. It's on every government health website in Europe. The WHO says keep it under 5 grams of salt per day (about 2,000 mg of sodium). The European Commission broadly agrees.

And for a large portion of the population, that advice makes perfect sense. But there's a problem: these guidelines were built for people eating a modern Western diet dominated by processed food. If that's not you — if you eat mostly whole, unprocessed foods, cook your own meals, and avoid junk — the recommendation might actually be steering you in the wrong direction.

Where your sodium actually comes from

Here's the number that puts everything in context: in Western diets, 70–75% of dietary sodium comes from processed and restaurant foods. Not from the salt shaker. Not from electrolyte supplements. From packaged meals, cured meats, bread, sauces, ready-made soups, and fast food.

This has been documented extensively. Data from Harvard's School of Public Health and the US Centers for Disease Control and Prevention (CDC) consistently shows that ultra-processed foods are the dominant source of sodium in Western diets. A controlled trial comparing ultra-processed vs. unprocessed diets (matched for calories) found dramatically higher sodium intake on the processed diet.

This means the government recommendation to "reduce sodium" is essentially telling people to eat fewer processed foods. That's good advice. But for the person who already avoids processed foods, the implication is very different.

If you cook your own meals from whole ingredients — fresh vegetables, meat, fish, eggs, rice, potatoes — you're probably getting far less sodium than the average person. The sodium recommendations assume you're getting 3,000–4,000 mg per day from food and telling you to cut back. If you're getting 1,500 mg from your clean diet, being told to "reduce sodium" makes no sense.

The J-shaped curve: when less sodium is worse

This is where it gets really interesting. One of the largest and most significant studies on sodium and health outcomes was published in 2014 in the New England Journal of Medicine. It was part of the PURE study — a massive global research project that tracked over 100,000 people across 17 countries.

The finding: the relationship between sodium intake and cardiovascular risk isn't linear. It's J-shaped. Both very high sodium intake (above 7 grams per day) and very low sodium intake (below 3 grams per day) were associated with increased risk. The lowest risk zone? Between 3 and 6 grams of sodium per day.

Read that again. The optimal range, according to this study, starts at 3 grams per day — which is 50% higher than what most European guidelines recommend as the maximum. And the risk of going too low appears to be real.

Low sodium increases cardiovascular risk

Three years before the PURE study, a study published in JAMA examined the relationship between urinary sodium excretion and cardiovascular events. The researchers followed nearly 29,000 patients with cardiovascular disease or diabetes.

Their finding: sodium excretion below 3 grams per day was associated with an increased risk of cardiovascular death and hospitalisation for heart failure, compared to moderate excretion (4–6 grams per day).

This doesn't mean everyone should start eating more salt. But it does suggest that aggressive sodium restriction — particularly for active people who are already eating clean — may not be as universally beneficial as the standard advice implies.

Chronic dehydration ages you faster

A 2023 study published in eBioMedicine (part of The Lancet family) added another dimension to the conversation. Researchers examined the relationship between serum sodium levels (a proxy for hydration status) and biological aging.

Adults with serum sodium at the higher end of the normal range — indicating chronic, low-grade dehydration — were more likely to develop chronic diseases and showed signs of accelerated biological aging. Higher serum sodium was also associated with premature mortality.

The active, healthy eater's paradox

Here's the uncomfortable truth: the people who are most likely to be sodium-deficient are often the people who care most about their health. They eat whole foods (low sodium). They exercise regularly (high sodium loss through sweat). They drink lots of water (which can dilute sodium further). They limit processed foods (eliminating the biggest sodium source in modern diets). They may follow low-carb or ketogenic diets (which cause increased sodium excretion).

These are all healthy behaviours. But combined, they create a scenario where sodium intake can fall well below what the research suggests is optimal, particularly the 3–6 gram range identified by the PURE study.

A note on citing this research

We want to be transparent about something. The studies cited above are real, peer-reviewed, and published in some of the world's most prestigious medical journals. But they remain debated in the nutrition science community. Some researchers argue the J-curve findings are subject to confounding factors, and traditional dietetic organisations continue to recommend lower sodium targets.

We're not making health claims. We're sharing what the published research has found, so you can make your own informed decisions. If you have hypertension, kidney disease, or any condition affecting sodium metabolism, follow your healthcare provider's specific guidance.