Is a low-salt diet as unhealthy as having too much?

Some scientists argue that eating too little salt may be just as harmful as consuming too much, according to an article published by the BBC.

Salt, or sodium chloride, is vital for maintaining the body's fluid balance and nerve function.

Yet, most people around the world consume nearly twice the recommended amount, increasing the risk of high blood pressure, stroke, and heart disease.

The World Health Organization (WHO) advises adults to limit daily sodium intake to less than 2g, which can be obtained from about 5g of salt.

Average salt consumption, however, is much higher — around 8.4g per day in the UK, 8.5g in the US, and nearly 10.8g globally.

Only a quarter of this comes from salt added during cooking or at the table, while the rest is hidden in processed foods such as bread, sauces, and cereals.

Research shows that high salt intake raises blood pressure as the body retains water to dilute sodium, putting pressure on arteries.

The WHO estimates that excessive sodium consumption contributes to 1.89 million deaths globally each year.

A meta-analysis of 13 studies found a 17% higher risk of cardiovascular disease and a 23% greater risk of stroke from consuming just 5g more salt daily.

Evidence also suggests that lowering salt intake can reduce blood pressure and heart-related deaths.

For example, an eight-year study in England linked a 1.4g daily reduction in salt to a sharp drop in stroke and heart disease fatalities.

Similar national campaigns in Japan and Finland produced comparable results.

However, the issue is not clear-cut.

Studies cited by the BBC show that individual responses to salt vary depending on factors such as age, ethnicity, weight, and genetic predisposition to hypertension.

Some researchers even claim that a low-salt diet could increase cardiovascular risk, suggesting that both very low and very high consumption levels are harmful — a pattern known as a J- or U-shaped curve.

One large-scale study involving 130,000 people found that consuming less than 7.5g of salt daily was linked to higher rates of heart problems and death, while moderate consumption up to 12.5g showed fewer risks.

Critics, however, argue that such studies rely on flawed methods and are sometimes influenced by the food industry.

Health experts quoted by the BBC, including Professor Francesco Cappuccio of the University of Warwick, maintain that reducing salt intake benefits everyone, regardless of individual differences.

The British Nutrition Foundation also supports moderate reduction, noting that extremely low levels are uncommon and difficult to achieve given the salt already present in most foods.

Some researchers say the negative effects of salt can be mitigated by a diet rich in potassium from fruits, vegetables, and dairy.

But the consensus remains that excessive salt intake raises blood pressure and harms heart health.

In short, while debate continues over how little salt might be too little, most experts agree that cutting down from current high levels is beneficial for everyone.