The exact amount of salty foods you can actually eat without risking your health, according to science

Even small increases in the amount of salt you eat could be raising your risk of heart disease, scientists have warned.

In a study that tracked 25,000 adults for a decade, researchers found that for every 1,000 milligrams (mg) of sodium, salt, consumed, the risk of heart failure rose by about eight percent.

Heart failure, a condition where the heart is too weak to pump blood around the body sufficiently, was linked to higher sodium intake independent of other factors such as physical activity, total calories or cholesterol levels.

Just 1,000 mg of sodium per day is roughly equivalent to one tablespoon of soy sauce or one can of tomato soup.

Participants in the study were in their 50s, based in the southern US, from a low-income background, had no pre-existing heart conditions and consumed about 4,200mg of sodium daily on average.

Over the 10-year period, 27 percent of participants, or 7,000 individuals, developed heart failure. 

Dr Deepak Gupta, a cardiologist at Vanderbilt University who led the study, told Daily Mail: ‘My recommendation for most people is to follow the guidelines for sodium intake and I think our study helps reinforce those recommendations. 

‘Of course, individualized plans should be developed in consultation with one’s doctor or healthcare provider.’

The American Heart Association recommends that people do not consume more than 2,300mg of sodium per day. Those with high blood pressure are advised not to consume more than 1,500mg of sodium every 24 hours. 

Robert F Kennedy Jr’s new food pyramid, published in January, also recommends consuming no more than 2,300 mg of sodium per day. 

However, Americans consume an average of 3,400 mg of sodium daily, estimates suggest. The additive is widely available in the American diet, particularly in processed and fast food and restaurant meals, where it is used to enhance flavor.

About 127 million people have heart disease, or nearly half of all Americans, estimates suggest, while 6.7 million suffer from heart failure.

Researchers have warned for decades that consuming salt raises the risk of heart complications, particularly among those already diagnosed with a heart condition.

Scientists say this is because the excess sodium can cause the body to retain more water, raising blood pressure and forcing the heart to work harder to pump blood, which can weaken the muscle and cause conditions such as heart failure over time.

High blood pressure can also damage arteries, raising the risk of plaques becoming dislodged and blocking vessels, triggering a stroke or heart attack. 

Harvard University scientists said in 2018 that studies had established a clear link between higher sodium intake and heart problems among those with pre-existing heart conditions.

But they said, for those without a heart condition and who were eating moderate amounts of sodium, there was no clear evidence that slashing their intake reduced their risk of cardiovascular problems.

For the new study, published in the journal JACC: Advances, researchers analyzed data on participants in the Southern Community Cohort Study, a long-running project that tracked people in the southeastern US to better understand the causes of cancer and other chronic conditions.

Participants were enrolled between 2002 and 2009, 69 percent were black and 87 percent earned less than $25,000 per year. All were enrolled in Medicare and Medicaid.

Their dietary intake was tracked using self-reported questionnaires that were completed every five years. Participants reported any health events.

Researchers analyzed the results to determine how sodium consumption affected the risk of suffering from heart failure. 

Overall, the researchers also found that consuming 4,200mg of sodium per day — almost twice the recommended maximum — led to a 15 percent higher risk of heart failure when compared to consuming the amount in the dietary guidelines.

Based on their analysis, they said that dropping dietary consumption of sodium down to even 4,000mg per day could prevent 6.6 percent of new heart failure cases over a 10-year period.

The scientists wrote in their conclusion: ‘Among low-income Black and White adults in the southeast United States, greater dietary sodium intake associates with a higher risk of incident heart failure. 

‘Modest reduction in sodium consumption may significantly reduce the burden of heart failure in this high-risk population.’

Limitations of the study included that it relied on self-reported dietary intake, with participants not required to provide proof of what they consumed.

It was also in a group that was not generally representative of the whole US population.