Salt study finds big heart risk

The Globe and Mail – An extra teaspoon of salt increases a person’s risk of stroke by 23 per cent and their risk of developing heart disease by 17 per cent, according to a new study.

The research, published in today’s edition of the British Medical Journal, was led by Pasquale Strazzullo of the University of Naples in Italy.

His team compiled the results of 13 studies, involving more than 170,000 people, that were published between 1996 and 2008. The researchers examined the direct correlation between salt consumption and heart disease and stroke, and found that more than 10,000 heart attacks and strokes could be directly attributed to excess salt consumption.

(The knock against research in the field is that while it has been amply demonstrated that consumption increases blood pressure and that high blood pressure increases cardiovascular risks, rarely is the direct link examined.)

Dr. Strazzullo and his team estimated that if people worldwide consumed no more than the recommended upper limit of five grams of salt daily (one teaspoon – or half the average consumption today), as many three million cardiovascular deaths and 250,000 stroke deaths could be averted annually. (Table salt is actually sodium chloride and 40 per cent of it, by weight, is sodium.)

‘These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease,’ he said.

Canadians consume, on average, 7.7 grams of salt daily, well above the recommend level. In Europe, where this study was published, salt intake is measured in grams.

In North America, sodium – as opposed to salt – intake is the measure of choice. Canadians consume, on average 3,092 milligrams of sodium daily, more than double the recommended amount.

Regardless of the measure used, the ‘projected benefits of salt reduction are substantial,’ said Lawrence Appel, a professor of human nutrition at Johns Hopkins University in Baltimore, Md.

He said that, if anything, the new research likely underestimates the negative impacts of salt consumption because there is ‘systematic under-reporting of salt intake.’