Estimating the Impact of Salt Reduction in Packaged Soups on Public Health
Many people do not realize that salt is an essential nutrient. The sodium in table salt regulates fluid in the body and is needed for the proper functioning of nerves and muscles. Salt is also often used as a fortification vehicle for iodine. Salt is used across the globe as a seasoning, food processing aid (for example, the production of cheese requires salt to help the curd separate from whey) and it also offers a means of food preservation.
As with everything, we can have too much of a good thing. High consumption of salt can cause hypertension and contributes to cardiovascular disease risk. It has also been implicated in bone mineral loss when calcium consumption is low. On a global basis, the average person consumes around twice as much as the recommended maximum amount of salt (see a large, international survey of two decades of salt consumption by Powles and associates). In Europe and the US, packaged foods make a large contribution to salt intakes. Food producers can play an important role in reducing the levels of salt in their products that can have a measureable impact on the global burden of cardiovascular disease.
Dotsch-Klerk and colleagues report on an approach to model the effect of a small reduction in the sodium content of a single type of food commonly consumed in many countries: packaged soup. While soup is by no means the only contributor of salt to people’s diets, it represents a food category that is consumed in reasonable amounts by many people. In this case, the effect of reducing the salt content of soup in the Netherlands by 25% on stroke, heart attacks, angina pectoris and heart failure was used as an example. The authors, who were from a large, multinational food producer, considered a 25% reduction in the salt content of the food to be technically feasible and acceptable to consumers when done in stages.
On average, Dutch people consume 50 g soup per day. This translates to half a gram of salt. As there is a dose-response relationship between salt and blood pressure, reducing the salt content of all soups by 25% would result in a decrease in overall systolic blood pressure of 0.11 mmHg. This tiny reduction would not make my cardiologist happy, but on the population level, it can have a significant impact. The authors calculate a reduction in mortality by around 50 averted deaths a year, and 300 fewer cases of stroke, heart attacks, angina and heart failure.
By modelling the effect of a modest reduction of salt in a single category of food products, soup, the authors were able to predict a small decrease in mortality and cardiovascular disease. Imagine what would happen if the food industry could reduce the salt content of more types of foods?
Mariska Dotsch-Klerk, Maaike Bruins, Joep Matthee, Mary Kearney, Kathelijn van Elk, Peter Weber, Manfred Eggersdorfer. FENS 2015 European Nutrition Conference abstract 149/816 A modelling approach to estimate the impact of sodium reduction in soups on cardiovascular health in the Netherlands. Poster session 3, October 22. 13.35 - 14.30 h. http://www.fensberlin2015.org/?seccion=programme&subSeccion=detailProgramme&id=144
Bruins MJ, Dötsch-Klerk M, Matthee J, Kearney M, van Elk K, Weber P, Eggersdorfer M. A Modelling Approach to Estimate the Impact of Sodium Reduction in Soups on Cardiovascular Health in the Netherlands. Nutrients. 2015 Sep 17;7(9):8010-9. doi: 10.3390/nu7095375. http://www.ncbi.nlm.nih.gov/pubmed/26393647
Powles J, Fahimi S, Micha R, Khatibzadeh S, Shi P, Ezzati M, Engell RE, Lim SS, Danaei G, Mozaffarian D; Global Burden of Diseases Nutrition and Chronic Diseases Expert Group (NutriCoDE). Global, regional and national sodium intakes in 1990 and 2010: a systematic analysis of 24 h urinary sodium excretion and dietary surveys worldwide. BMJ Open. 2013 Dec 23;3(12):e003733. doi: 10.1136/bmjopen-2013-003733. http://www.ncbi.nlm.nih.gov/pubmed/24366578