An extremely effective and simple piece of preventative medicine? Get patients to cut down on salt

Too much of anything that’s good for you can be bad. And if anything, Canadians consume far more sodium than is good for them. Indeed, in some cases, it’s killing them—which is why Health Canada announced that starting in early 2026, Canadians will see sodium warning labels on the front of packaged food.The move is meant to help relieve the burden that excess sodium has on cardiovascular disease (CVD) and mortality rates. About a third of hypertension cases are caused by excess dietary sodium, translating to about 2.5 million people in Canada.Samples of what the warning labels will look like are on the Health Canada website.Front-of-package nutrition labeling is widely recognized as an effective tool to help counteract rising rates of diet-related chronic disease, a Health Canada spokesperson told the Medical Post in an email. However, eating out can still consist of salt-filled meals.“In general, most foods sold in restaurants and food service establishments, as well as foods ordered for take-out and delivery, are not considered to be prepackaged and are thus exempt from offering nutrition labels,” the email said. Some establishments provide nutrition information voluntarily.The Global Burden of Disease study states that high blood pressure is the leading risk for death in the world, killing over 10 million people per year, according to Dr. Norman Campbell, professor emeritus of medicine, physiology and pharmacology at the University of Calgary. He has conducted multiple studies on sodium and health.“Even if you throw COVID in there and all other infectious disease, high blood pressure kills more people and disables more than all the infectious diseases . . .. But if you look down the list, after high blood pressure, dietary risks are right there; and sodium is the top dietary risk,” he said.An extreme example of too much salt was reported after a woman died after drinking a 1,000ml bottle of soy sauce—an intake of about 160 g of salt.In 2023, the World Health Organization (WHO) produced a report showing that issues from consuming too much sodium is a global health problem. The agency also produced a sodium reduction score card ranking countries in terms of their efforts to reduce excessive sodium intake. Canada has a mix of voluntary reduction efforts with mandatory measures in the works, but could do better. There are also score cards for sugar and trans-fatty acids.“The background of all this is reducing sodium in the diet is one of the most cost-effective things a government can do to improve the health of the population . . .. We saw the effects of COVID—how much it costs society to prevent COVID. The estimates are that reducing sodium in the diet saves the government $13 to $18 for every dollar it invests,” said Dr. Campbell.Why is sodium so bad?High sodium intake increases blood pressure, but over time it can damage blood vessels and lead to atherosclerosis, heart disease, strokes and kidney failure. Evidence also suggests excess sodium acts as an inflammatory agent and contributes to the severity of various inflammatory disorders, Dr. Campbell told the Medical Post in an interview.Consuming too much saturated fat and sugar increases inflammation too, and foods with those ingredients also will be graced with warning labels. Sodium, sugar and saturated fats are all linked to several chronic diseases such as diabetes, obesity and hypertension.Sodium’s contribution to stiffer vessels and hypertension is well elucidated. It can cause an increase in calcium excretion, which in turn can lead to kidney stones. It’s no surprise that one of the treatments for calcium kidney stones is to reduce dietary sodium.Yet the substance is ubiquitous, be it in packaged foods, eating out, or the table salt we add to food at home. In fact, it’s difficult to avoid consuming too much.In Canada 97% of men and 81% of women exceed the Adequate Intake level of sodium, as defined by Heath Canada, of 1,500 mg per day, and 74% of men and 49% of women exceed the Chronic Disease Risk Reduction level defined as up to 2,300 mg per day.While table salt is a common source of dietary sodium, extra sodium sneaks into baked goods via other sodium compounds. Sodium bicarbonate which is used as a rising agent hikes up the sodium content in baked goods. It appears in foods with the preservative sodium metabisulfite; and the flavour enhancer sodium glutamate. Plus, extra salt is tossed in to enhance the flavour of foods.These various forms of sodium compounds also appear to be problematic, said Dr. Campbell. And yes, specialty salts such as Himalayan salt are still sodium chloride salts.Canada’s 2017 Food Guide recommends consuming fewer than 2,300 mg per day of sodium. “But physiologically most people are fine with 1,500 mg per day or even a bit less,” according to Dr. Campbell.Going back a few generations, our ancestors got by on a much less sodium. “Really small amounts are naturally present in food. That’s pretty much all we need from just a physiologic perspective,” he said.Can people get too little sodium?That’s unlikely in this heavily salted world. Dr. Campbell noted a handful of studies suggest too little salt could increase the risk for CVD, but said the quality of those studies is low.Yet they are “used by the food industry to go after governments to hinder their efforts to reduce sodium,” he said.Fortunately, low-quality studies have not impacted the development of guidelines, but they have gotten around, casting doubt. Even in light of overwhelming evidence of the harms of excess sodium, some surveys suggest many Canadian physicians are not confident that reducing sodium is helpful.Even if people manage to get their overall sodium consumption down to safe levels, is it safe to occasionally binge on salty chips?“I’d say ‘yes’ and ‘no’,” said Dr. Campbell. Some people are more sensitive to its effects than others, such as those with heart failure or kidney failure—especially people on dialysis who could end up in hospital even with occasional excess.“Many of us will have a short-term increase in blood pressure, which should not produce a long-term adverse effect . . .. it’s a question of how often, and what’s too often,” he said. But chronic high intake generally has consequences.While on the topic of sodium, another substance to consider is potassium, which is known to reduce blood pressure. Though too little potassium can increase blood pressure.“About half of hypertension relates to too much sodium and too little potassium,” Dr. Campbell said. But it’s not as though you can use potassium to counter the effects of excess sodium. They appear to act independently and don’t necessarily directly interact, he said. Foods that are high in potassium tend to be fruits and vegetables, and happen to be generally low in sodium.Why do packaged foods contain so much salt?At the 7th Biennial Championing Public Health Nutrition conference, Dr. Francesco Cappuccio stated that industry uses sodium compounds for a variety of reasons. He is a professor of cardiovascular medicine and epidemiology at Warwick Medical School. As well as for flavor, salt contributes to food safety as a preservative, though levels could be much lower, he said. But salt is also used to add weight to products by helping retain extra water. “If we inject a piece of meat with a sodium (salt such as) polyphosphate, or polysulphate, and you immerse it water overnight, the salt will attract water. And they will do it before packaging the food. And the food will increase in weight and you would pay (for that),” he said.High-salt processed food leads to three lines of profit, Dr. Cappuccio said. The first is that increasing salt content down-regulates the taste buds which creates a salt craving and more demand for salty food. Remember the potato chip ad? Nobody can eat just one.The beverage industry adds salt which drives thirst, and a desire to drink more and sell more product. Sugars and fats also improve the taste of various products and help increase consumption, he said.But salt is an acquired taste. Because of this, if the amount of sodium is reduced gradually, people won’t notice because their taste for sodium changes as levels go down. Dr. Campbell concurred. “You can reduce sodium by about 10 per cent or less without anyone being able to detect it. What should doctors tell patients? Dr. Campbell suggested encouraging salt reduction in the context of a healthy diet. People need to be eating more fresh unprocessed foods and doing their own cooking. And stay away from packaged foods and less eating out. You could even ditch the salt shaker.

An extremely effective and simple piece of preventative medicine? Get patients to cut down on salt

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