The publication last week of a major research study into the effect of salt on human health suggests a need to revisit the substance’s negative reputation. The Prospective Urban and Rural Epidemiological (Pure) study found that while consuming large amounts of salt is still bad for our health, too little salt in our diet may not be a healthy option. It assessed sodium and potassium intake, and related both to blood pressure, heart disease and stroke.
Canadian and Irish researchers concluded that, compared to average consumption, low sodium intake reduces blood pressure modestly. However low sodium intake also has negative effects, including elevations of certain hormones that are associated with an increased risk of cardiovascular disease.
This latest research is the strongest yet to support the thesis that salt has a physiological role in the human body; in essence, we need some salt for our cells to function optimally. By showing harm among people whose salt intake was less than 3 grams per day, in the form of increased mortality and a greater chance of heart attack and stroke, the authors have strengthened the evidence for some daily minimum level of sodium intake. The Pure study suggests a moderate salt intake is the healthy option for most of the population. However, for people with high blood pressure, even a moderate daily sodium intake poses a health risk and this group must continue to pursue a low salt diet.
Currently, public health experts remain in favour of reducing average salt intake across the whole population, citing evidence that this is associated with population-wide health benefits. Much of our salt intake is hidden in processed foods, so that reducing table salt consumption alone may not be sufficient.While this latest research suggests the current recommended healthy daily ceiling for salt consumption may be set too low, any change to dietary guidelines must take place by consensus based on a totality of scientific evidence.