A new study is questioning whether there's really any benefit for people with normal blood pressure to cut back on salt in their diet.

The study, which appears in JAMA, the Journal of the American Medical Association, found that people who ate lots of salt were no more likely to develop high blood pressure than those with a low salt intake.

They were also less likely to die of heart disease. In fact, people in the study who ate the least amount of sodium actually had slightly higher death rates from heart disease.

The study authors emphasize that their study focused on otherwise healthy people and that reducing salt intake is still important for those with high blood pressure.

But they conclude that their findings "do not support the current recommendations of a generalized and indiscriminate reduction of salt intake" among healthy people.

Current guidelines from Health Canada recommend that adults not exceed 2,300 mg of sodium per day. But data indicate that Canadians consume an average of 3,092 mg daily.

But the researchers in this study says there have bee no long-term studies that show that a lower salt intake leads to better overall heart health or fewer deaths in the wider population.

For this study, the researchers looked at data from two studies that incorporated almost 3,700 Europeans with an average age of about 40. None of the participants had heart disease or high blood pressure at the outset.

All of the participants had their salt consumption measured through urine samples taken at the start and the end of the studies.

The researchers then broke the participants up into three groups: those with highest and lowest salt intakes, and those with average intake.

They then followed them for an average of eight years, determining how many were diagnosed with heart disease, and in a smaller group, how many got high blood pressure.

About one in four of all the study participants who started out with normal blood pressure were diagnosed with high blood pressure during follow up.

But those with the lowest levels of sodium — those who ate an average of nearly 2,500 mg per day — had no greater protection against high blood pressure after eight years than those who consumed the highest levels -- nearly 6,000 mg per day on average.

They also found that heart disease deaths decreased with higher sodium intakes:

  • 50 deaths occurred in the third of participants with the lowest sodium intakes
  • 24 deaths in the third who had medium intakes
  • 10 deaths in those with the highest intakes

The researchers did find that those eating the most salt had, on average, a slight increase in systolic blood pressure, which is the top number on a blood pressure reading: a 1.71-millimeter increase in pressure for each 2.5-gram increase in sodium per day. But these people were no more likely to develop full-blown hypertension.

The authors concede there were some limitations with their study. They note that while the urine test is effective for assessing sodium intake over 24 hours, it "might be insufficient to characterize an individual's habitual salt intake."

They also note that since the study participants were relatively young, the number of heart events was small so the risk of excessive sodium intake might not be noticed.

As well, the study looked only at white Europeans so the findings might not apply to other ethnic groups who might be more salt sensitive.

Dr. Peter Briss, a medical director at the U.S. Centers for Disease Control and Prevention felt so strongly that the study was flawed that he criticized it in an interview with The New York Times.

The study flies in the face of a body of evidence indicating that higher sodium consumption can increase the risk of heart disease.

"At the moment, this study might need to be taken with a grain of salt," he said.