Over consumption of salt is a global health issue. Excessive sodium consumption is linked to a higher risk of cardiovascular disease (CVD) and stroke.1,2
Considering that Canadians consume an average of 3400mg of sodium/day,1
should we be concerned? United Kingdom and France also have high intakes, which vastly exceed the World Health Organization (WHO) recommended level of less than 2000mg daily.2
Median intakes of salt in the United States are similar to Canadian levels. It is postulated that these numbers may be even higher than the research shows as studies on salt consumption are generally based on self-reported data. People are likely to underestimate the true amount of food consumed.4
In Canada, the majority of sodium consumed (77%) comes from processed food.1,2
This may explain why people may not be aware of how much sodium they are actually consuming.
The recommendation to reduce dietary sodium has many merits. There is little question that diets excessive in sodium (i.e. well above the upper limit of 2300mg/day), are associated with health risks. Most of us could benefit from eating less of it. This seems straightforward enough.
There is, however, some controversy when it comes to dietary sodium intake:
- How much sodium should people consume?
- Should the amount of sodium we recommend be titrated in terms of energy requirements?
- Is it possible we could actually be harming people by recommending too little sodium?
- Widespread sodium reduction messages are aimed at the healthy public in an effort to prevent some chronic diseases. Should we apply the same recommendations to hospitalized patients?
Finally, the World Health Organization (WHO) focuses not only on sodium, but on sodium to potassium ratios.4
Similarly, the Dietary Approaches to Stop Hypertension (DASH) diet focuses not only on sodium reduction but also on adequate intake of potassium, magnesium, and dietary fibre.4, 5
In light of this, one wonders if we should be looking at dietary patterns, rather than focusing on specific nutrients.
How much sodium should we recommend?
Let’s start with the amount of sodium we should recommend. Well recognized, leading health organizations are not in agreement on this point (see table below). Each organization uses a rigorous expert consensus building process, yet there is still not enough conclusive data to support unified global recommendations about how much sodium the population should consume.
Examples of current recommendations:
|World Health Organization
|Adequate Intake in Canada
||9-50 years old: 1500mg/day
Over 50 years old: 1300 mg/day
|Upper Limit in Canada
|Recommended Daily Allowance (RDA) in France
|American Heart Association
|US Dietary Guidelines
||< 2300mg/day (1500mg/day for subgroups at risk)
|Institute of Medicine (IOM)
||2300mg/day (cautions that there is not enough evidence to support recommending 1500mg/day)
For example, the Canadian Diabetes Association 2013 Clinical Practice Guidelines note that there is concern that sodium intakes near the suggested adequate intake (AI) may be associated with increased mortality in people with both type 1 and type 2 diabetes.6,7,8
While association is not necessarily causation and may be explained by the fact that these patients are sick and may be eating little of all nutrients, it does make one consider possible risks to limiting sodium in this population. Given the high number of patients in hospitals with type 2 diabetes, I am concerned about not providing enough sodium to vulnerable patients.
In hospitalized patients with acute heart failure, there is a lack of evidence reporting benefits of sodium and fluid restrictions.9, 10
Aliti et al. assert that sodium and fluid restrictions in patients admitted with heart failure are unnecessary and widespread recommendations to restrict sodium in these patients have little supportive evidence.9
They conclude that providing liberal sodium and fluid intake in patients with acute heart failure is in the patient’s best interest. Weiss asserts that given the lack of evidence to support the use of low sodium diets in heart failure patients, patients should be discouraged from limiting sodium intake to less than 2300mg/day.11
This investigation into recommended intakes is especially relevant in terms of recent findings by the Canadian Malnutrition Task Force (CMTF). The CMTF have found that the prevalence of malnutrition in adult hospitalized patients in Canada is 45 percent.12
Malnutrition in hospitals contributes to increased length of stay and poorer patient outcomes. It is vital that patients enjoy the taste of foods provided in hospitals so that they will eat enough to meet their needs.
Personally, I have encountered patients who are not eating enough because the low sodium hospital food is not palatable to them. This is especially evident in patients who are used to consuming a high salt diet at home. Such patients need time to adjust to the taste of a diet that is lower in sodium. While low sodium foods may be one factor affecting malnutrition in hospitals, there are many other contributors as well, such as loss of appetite, tray accessibility, opening packaged items, and fasting for tests.
I posit that hospital menus that strive to meet the AI for sodium are unintentionally contributing to malnutrition in hospitals. I question the movement to provide only 1500mg of sodium per day in hospital menus. I also question the merit of ordering sodium restricted diets for every patient that comes in with heart failure or even acute coronary syndrome.
Many hospitalized patients experience poor appetite and it is a struggle to meet their energy and protein requirements. Categorically disallowing a salt package, especially knowing that a standard salt package (at my hospital) provides only 285mg of sodium, does not make sense to me. It could make the difference between patients eating or not. And, in many cases, allowing a salt packet is in the best interest of the patient. Instead of categorically disallowing salt packages, a dietitian should assess whether allowing them is acceptable on an individual basis (as able).
There is little question that diets excessive in sodium are unhealthy. In general, people consume too much sodium and not enough potassium. However, given that in Canada the majority of the sodium is coming from processed foods, it seems logical that our message to our patients pertaining to sodium should focus on this issue. Less emphasis should be placed on the issue of avoiding salt in cooking and at the table because added salt accounts for a mere 11% of sodium consumed.1,2
The foods served in hospitals should be minimally processed and menus should not be so restrictive in salt that the food is bland and tasteless. Moreover, a menu that provides between 2000 and 2300mg of sodium may be preferable in terms of health benefits to one that contains 1500mg of sodium or less. Hospitalized patients should be assessed by a dietitian to see if providing more salt with their meals is warranted. This has the potential to help increase nutrient intakes, and ultimately, reduce length of stay.
Since doing this research, I have become much more comfortable allowing salt packages on patient trays, even if a patient is on a cardiac diet. Prior to this, I felt torn about providing it. I wanted patients to eat more and I wanted to please them but I worried I may be causing harm if I gave them a salt package.
Knowing that a salt package contains 285mg of sodium, and that the sodium content of the home-cooked meals we serve at our facility is very low, makes me feel confident that providing a salt package is in a patient’s best interest. I have changed my patient education to focus on limiting processed foods, and feel better informed when speaking with staff, interns, and patients and their families about sodium.
Editor’s note: The wide variety of sodium recommendations in the table above is bewildering. What do you think about sodium recommendations in your hospital or in general? Should patients be provided more salt with their meals? Please share your thoughts and comments below.
- Health Canada. Guidance for the food industry on reducing sodium in processed foods. Retrieved from http://www.hc-sc.gc.ca/fn-an/legislation/guide-ld/2012-sodium-reduction-indust-eng.php
- Health Canada. Sodium reduction strategy for Canada. Retrieved from http://www.hc-sc.gc.ca/fn-an/nutrition/sodium/related-info-connexe/strateg/reduct-strat-eng.php
- O'Donnell, M. J., Yusuf, S., Mente, A., Gao, P., Mann, J. F., Teo, K., ... & Probstfield, J. (2011). Urinary sodium and potassium excretion and risk of cardiovascular events. Jama, 306(20), 2229-2238.
- Drewnowski, A., Rehm, C. D., Maillot, M., Mendoza, A., & Monsivais, P. (2015). The feasibility of meeting the WHO guidelines for sodium and potassium: A cross-national comparison study. BMJ open, 5(3), e006625.
- World Health Organization. (2012). Guideline: Sodium intake for adults and children. Retrieved from www.who.int/nutrition/publications/guidelines/sodium_intake_printversion.pdf
- Canadian Diabetes Association. (2013). Clinical practice guidelines. Retrieved from http://guidelines.diabetes.ca/fullguidelines
- Thomas, M. C., Moran, J., Forsblom, C., Harjutsalo, V., Thorn, L., Ahola, A., ... & Groop, P. H. (2011). The association between dietary sodium intake, ESRD, and all-cause mortality in patients with type 1 diabetes. Diabetes Care, 34(4), 861-866.
- Ekinci, E. I., Clarke, S., Thomas, M. C., Moran, J. L., Cheong, K., MacIsaac, R. J., & Jerums, G. (2011). Dietary salt intake and mortality in patients with type 2 diabetes. Diabetes care, 34(3), 703-709.
- Aliti, G. B., Rabelo, E. R., Clausell, N., Rohde, L. E., Biolo, A., & Beck-da-Silva, L. (2013). Aggressive fluid and sodium restriction in acute decompensated heart failure: A randomized clinical trial. JAMA Internal Medicine, 173(12), 1058-1064.
- Dietitians of Canada. Cardiovascular Disease-Heart Failure: Background. In Practice-based Evidence in Nutrition [PEN]. 2010. Access by subscription.
- Weiss, B. D. (2014). Sodium restriction in heart failure: How low should you go? American Family Physician, 89(7), 508.
- Allard, J. P., Keller, H., Jeejeebhoy, K. N., Laporte, M., Duerksen, D. R., Gramlich, L., ... & Teterina, A. (2015). Malnutrition at hospital admission—Contributors and effect on length of stay a prospective cohort study from the Canadian Malnutrition Task Force. Journal of Parenteral and Enteral Nutrition, 0148607114567902.