How much salt is too much?

Canadian blood pressure experts are gathering today in Montreal to debate whether to change guidelines to raise the recommended level of sodium, which could have implications for consumers and the food industry.

Hypertension Canada's education task force is sifting through the latest scientific evidence at a meeting Thursday, to determine the acceptable level of sodium intake for consumers.

On average, Canadians consume 3,400 mg of sodium every day, mostly through processed foods rather than the salt shaker. (Cliff Owen/Associated Press)

Most people take in an average of 3,400 mg of sodium per day, more than twice the recommended level of 1,500 mg/day for people nine to 70 years old, according to Health Canada.

Hypertension Canada said the debate is whether to advise Canadians to aim for less than 2,300 mg of sodium per day. Doing so would raise the "acceptable" level of sodium from one-quarter to a little less than a half a teaspoon a day. If approved, the new recommendation would urge people to cut their sodium intake by about a third, compared with the 56 per cent reduction previously recommended.

Some members of the task force panel believe the current level may be unrealistic.

"Canadians are being held hostage by the food processors.They're stuck having more salt in their processed food than almost any other country in the world. That's a given," said Dr. Ross Feldman, a hypertension specialist in London, Ont. who speaks for the expert panel.

The deliberations may "sound like kind of a dry debate, but it turns out to be a big deal," in terms of how aggressively public health experts campaign to limit sodium in processed foods, he said.

Advice to lower sodium intake is based on the belief that lower levels reduce blood pressure, which results in fewer heart attacks and strokes.

Some believe the current guideline is too strict and unrealistic. They point to recent research suggesting that severely restricting sodium has also been linked to higher rates of heart attacks, strokes and congestive heart failure.

Some dietary salt is needed so it's question of getting a balance, Feldman said.

Health Canada doesn't have to follow the panel's recommendation but historically it has.

In May, an NDP private member's bill to implement sodium reduction failed to pass. It would have phased in lower sodium levels in prepackaged foods.

Also in May, the Institute of Medicine, which advises the U.S. and Canadian governments, concluded that new studies support efforts to reduce "excessive" sodium intake to lower risk of heart disease and stroke, but more research is needed on lowering dietary sodium to 1,500 mg/day in the general population.

In a commentary published in this month's issue of the American Journal of Hypertension, Dr. Salim Yusuf, Heart and Stroke Foundation of Ontario chair in cardiovascular disease at McMaster University in Hamilton, Ont. and his co-authors pointed to the Institute of Medicine committee's conclusions.

The commentary called for large studies measuring sodium in urine of healthy individuals to understand the association between sodium intake and cardiovascular disease.

The Hypertension Canada panel will formally present their recommendations on Saturday.