Too little salt 'could increase risk of heart attack or stroke'
Cutting back your salt intake to half the recommended amount per day could increase the risk of having a heart attack or stroke, according to a controversial new study.
The consensus up to now has been that we are eating too much salt, often hidden in processed foods, and we should have no more than 6g a day.
People suffering with high blood pressure need to be particularly careful of how much salt they eat.
However, Prof Martin O'Donnell of NUI Galway, who co-authored the study, said: "People should not obsess about their salt intake."
The study says that eating too little salt could increase the chances of dying from a heart attack or stroke.
The global analysis of more than 130,000 people found that there were more heart attacks, strokes and deaths among those whose salt intake was lower than the average amount.
It finds that lowering salt intake is best targeted at people with high blood pressure who have high salt diets, and questions the perceived wisdom of recommending a low salt intake for the entire population.
The publication of the report in 'The Lancet' sparked a strong backlash from the American Heart Association and a senior official in the World Health Organisation (WHO) who expressed "disbelief" that such "bad science" could be published by the prestigious journal.
However, Prof O'Donnell, who carried out the study with the Population Health Research Institute in Canada, told the Irish Independent he is standing by the findings and fully expected the backlash.
"People should not obsess about their salt intake. I see people who have made themselves miserable trying to keep to a very low-salt diet.
"You need a certain amount of salt in your diet. In a country like Ireland, it is usually buried in the foods you are eating.
"We are not saying people can add salt to foods at the table.
"What we are saying to people is to put the energy into a balanced diet, not trying to pick out one particular nutrient."
He said the peer-reviewed study looked specifically at whether the link between salt intake and death, heart disease and stroke is different in people with high blood pressure compared to those with normal blood pressure. The results showed that regardless of whether people have high blood pressure, low salt intake is related to more heart attacks, strokes, and deaths compared to average intake.
"Our findings are important because they show that lowering salt is best targeted at those with high blood pressure who have high-salt diets."
Reacting to the research, Prof Francesco Cappuccio, head of the WHO's Centre for Nutrition, said: "It is with disbelief that we should have bad science published in 'The Lancet'."
Prof O'Donnell said he welcomed the debate, saying it is healthy to challenge established dogma. Until there are findings on clinical trials, the debate will continue. Trials are underway in Galway on kidney patients.
"Our research says let us not set people up to fail with diet targets that are impossible to reach," he said. "I welcome the comments. If the research is strong enough, it can be defended.
"It is important that people with high blood pressure get it checked. That is the key thing.
"But hold off on putting salt on spuds. It is too much."