Under proposed revisions to Health Canada's food guide, Canadians could be advised to eat foods with little or no added salt, but the evidence on the benefits for healthy people is a grey area.

The new guide is expected to be out late this year or early in 2007, but the recommendation to limit salt is a controversial one.

The new guide is expected to limit salt intake.
(CBC)

It is accepted advice that people with hypertension should restrict their salt intake. Hypertension can cause strokes, heart attacks and kidney failure, and is one of the leading causes of death in Canada.

The World Health Organization and the Canadian Hypertension Society both say if everyone used less salt, rates of hypertension, heart attacks and strokes would drop.

"If we continue the way we're eating so many prepared foods and using too much salt in our diet, probably 80 per cent to 90 per cent of us will become hypertensive or get high blood pressure," said Dr. Charlotte Jones, an endocrinologist at a hypertension and cholesterol clinic in Calgary.

Dr. Charlotte Jones is an endocrinologist at a hypertension and cholesterol clinic in Calgary.
(CBC)

The big question is this: Is salt bad for people with normal blood pressure?

"We know that if you go to very low levels, you expose yourself to risk," said Dr. Sandy Logan, who studies diet and hypertension at Toronto's Mount Sinai Hospital. "If you go to very high levels you also expose yourself to risk. But there is a large grey area in between."

The salt industry is fighting the regulatory changes, and insists there is no scientific evidence to support salt restrictions across the board.

"Blood pressure will go down if they reduce dietary sodium," said Richard Hanneman of the Salt Institute, a U.S.-based trade association of salt manufacturers. "The question of course is whether that improves their health."

Logan agreed regulators may be moving too quickly.

"There may be benefit to being on a low-sodium diet, but let's get the evidence to show that."

It would take a large study in which some people eat a regular diet and others a low-sodium diet to see if lowering salt intake over many years does prolong life, but Health Canada officials feel confident telling Canadians to shake the salt habit.

Processed foods main source of salt

In the U.S., the Food and Drug Administration is being lobbied to regulate salt content in processed foods, the source of an estimated 80 per cent of the salt we consume.

People consume salt not only for its taste, but also to mask bitterness, Hanneman said.

Some food manufacturers are trying to reduce salt in prepared foods, but unlike sugar, it's not easily replaced in recipes, said Steve Graham of the Campbell Company of Canada.

The company is working to reduce salt across its line of soups, sauces and beverages, and is making an increasing number of low-sodium products.

But one replacement doesn't work for each product, so the company is using a combination of more vegetables, herbs or meat stocks to reduce salt while keeping the flavour, Graham said.