How much salt is in our food?

By Amanda Johnson 19/04/2012

A new study just published this week (16 April) by Canadian researchers has looked at the salt content of different foods in countries around the world, including New Zealand.

It’s an interesting paper! You’d think, for example, that if you ordered a burger from Burger King, McDonald’s, or KFC; or even a Subway sandwich, or a Domino’s pizza, that you’d get the exact same product from a particular company, with the same nutritional content, wherever you were in the world. Not so! In fact a McDonalds Big Mac provides 30% more salt in New Zealand than it does in the UK or France, and a Subway Club Sandwich provides more than twice as much salt in New Zealand than it does in France.

Overall, results show that New Zealand is comparable with Australia in terms of the amount of salt provided by the fast foods tested, but we have more salt in our fast food products than France and the UK, and less than the USA and Canada.

This study has attracted a bit of attention, both in New Zealand and internationally. The New Zealand Herald covered the story yesterday, and an article in Food News also mentioned the study. In addition, Fox News covered the story, along with ABC in Australia.

Salt is found in lots of foods — not only those tested in this study. In fact it has been estimated that only 15% of the salt we consume comes from the salt shaker — with a further 10% being provided naturally by foods. The rest comes from manufactured foods.

It’s important to avoid excess intakes of salt as this can lead to high blood pressure and increased risk of cardiovascular disease. It has been estimated that reducing our salt intake a third, from around 9g a day to 6g a day, could save over 900 Kiwi lives a year.

Dietitians New Zealand last year published a fact sheet on salt and health, which gives some nice tips on how to eat less salt, and the Heart Foundation in New Zealand has some great ideas on their website too, in relation to salt reduction.

Many food manufacturers are removing salt from their foods — but this study suggests that more could be done to reduce the salt content of some fast foods — as lower salt choices are being offered in different countries — with some countries (particularly France) offering foods with significantly lower salt levels. Clearly product formulation is not an issue.

In the meantime, I think following the advice of Dietitians New Zealand and the NZ Heart Foundation is a good starting point for anyone wanting to reduce their intake of salt.

0 Responses to “How much salt is in our food?”

  • I notice that the survey relies completely on the salt content reported by the companies themselves and these values are given without error estimates. The authors themselves recognise this limitation (though the reference given for this section seems to bear no relation to the point being made).

    I would be hesitant to condemn (or applaud) too broadly without this information. Different countries may have a systematic bias in testing methods that make differences more or less pronounced.

    It’s also a pity that they limited themselves to salt, one would think that only a little extra effort would have been required to collect the full nutritional information for each product and given a truly comprehensive database for comparisons. Multiple papers could then have followed. Perhaps this data is being turned into more papers as we type.

  • Interesting, but ultimately it doesnt show a low. Variability looks reasonably high, and if we want to know the differences, we need to analyse a suitable sample set of products worldwide. Or at the very least, its identification of the need for country specific, suitable, dietary reference datasets, such as the NZ composition database developed by Plant and Food.
    The bigger issue is “should we care”. Especially generic recommendations for a population.
    Yes, I know sodium can raise blood pressure, and we know that raised blood pressure is a risk for CVD, however, it is a logical flaw to say “therefore sodium increases risk for CVD. We also cannot take the angle of “blood pressure lowering with pharma reduces risk, therefore doing the same via sodium will reduce risk as well”

    If I was a food company trying to sell a health claim of “reducing sodium reduces risk of CVD” I would be asked for DBRCT to support this claim. However, for public health recommendations, we are happy with observational evidence? and if those dont rank highly within constraints of evidence based nutrition, we alter constraints to suit?

    A variety of governments around the world have spent 30 years recommending lowered sodium, but have not funded trials to confirm this observation. Why? Do we believe that the observational trials would hold up in clinical trials or not?

    Dennis Brier, at last years Nutrition Society conference in Queenstown, presented a chart showing how few observational associations were confirmed with RCT, and that list was not long. Would sodium be any different?

  • I am somewhat surprised that the CMAJ, a journal normally dedicated to higher level clinical studies, would publish what appears to be little more than a high school level Internet search of fast food chain websites, complete with conclusions demonstrating a complete lack of understanding of how food is formulated.

    Six out of the 10 authors are members of WASH (World Action on Salt and Health), whose singular goal is the international reduction of salt consumption. Their decade-long campaign against salt has been characterized by the complete denial of any peer-reviewed clinical evidence that counters this agenda and cautions against salt reduction.
    This has become more conspicuous during the last two years, when the overwhelming clinical evidence has clearly highlighted the risks of reducing current salt levels.

    While authors Dunford, Webster, Neal and Jenner note their conflict of interest as members of WASH at the end of the paper, Campbell and Jacobson make no such declaration, even though they are listed as WASH members. While there is no problem with anyone belonging to any sort of advocacy organization, it is important to let readers know if you have an intellectual attachment to a particular side of an issue in order for them to have a better understanding of the objectivity of the author and the motivation of the publication. The very act of refusing to acknowledge such a conflict of interest is in itself telling.

    It is clear that the authors know little about the food industry, nevertheless feel free to make judgments upon it. They do not appear to understand that localized food tastes dictate how foods are formulated. As an example in Canada, the same brand of beer will differ significantly in taste (sweetness, bitterness) depending upon the region it is brewed in, so that local tastes are satisfied. The huge success of micro-breweries is almost entirely due to the products satisfying a localized taste. If a pizza chain based in the US finds that clients in the UK don’t like as many anchovies as Americans do, of course the salt content will vary in the pizza between the two countries. You find local differences in the sweetness, spicing, and texture components in versions of same-name international chain products all around the world.

    The authors should also understand that food companies make food, not animal feed. Consumers have choices among products and it is the food industry’s business to know the specific food preferences of their clients.

    Food cannot be the same in every country. In Britain, Australia, New Zealand and South Africa, they eat salty autolyzed yeast spread in much the same way as Americans and Canadians eat peanut butter. Chacun a son gout (each to his/her taste) is not an idle expression – it’s a reflection of reality. We even make fun of each other’s eating preferences.

    Let’s not forget that the big secret of the heart healthy Mediterranean diet is that it is higher in salt than the American or Canadian diet. This is understandable because it is a far more traditional diet and traditional foods are far higher in salt than any modern processed foods, because in the past salt was not only used for taste, but also for preservation (a function that has largely been taken over by refrigeration and freezing in more modern diets). Parmesan, gorgonzola, feta, olives, anchovies, prosciutto, salt cod, bottarga, babaganoush, etc., etc., are all very high in salt, yet the people around the Mediterranean have some of the best cardiovascular figures in the world.

    The authors presume that salt reduction is a simple process with no technical difficulties. Yet, when a highly competent company with a household brand name stepped up to the bat and laid its century-long reputation on the line to cater to the wishes of the anti-salt zealots, it proved to be a great and very costly gamble. Making sweeping statements about what the industry should do holds no risks whatsoever for the desk-bound authors of this paper, but it does hold great risks for the food industry.

    And it also holds great risks for the public. If per capita sodium consumption (taken from the Intersalt study) is plotted against life expectancy, the data indicates that the higher the sodium consumption, the higher the life expectancy. While I’m not implying any cause and effect relationship between sodium intake and lifespan, the data does demonstrate the compatibility between life expectancy and the associated levels of sodium intake.

    As I eluded to earlier, the preponderance of peer-reviewed medical studies recently published, have cautioned against population-wide salt reduction (1,2,3,4,5,6,7), including the latest one demonstrating that anyone who follows the 2010 Dietary Guidelines for sodium will end up with a highly unbalanced and nutritionally inadequate diet (8). This evidence proves beyond all doubt that the 2010 Dietary Guideline for sodium is bogus and will do the public far more harm than good. Unfortunately, our public health authorities have neither the courage nor conviction to put things right. It’s a pity that they have forgotten that they work for consumers.

    Morton Satin – Salt Institute, Alexandria, VA

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    2)Garg R., Williams GH, Hurwitz S, Brown NJ, Hopkins PN, Adler GK. Low-Salt Diet Increases Insulin Resistance in Healthy Subjects, Metabolism. 2010;60(7):965-68. Epub 2010 Oct 30.
    3)Stolarz-Skrzypek K, Kuznwtsova T, Thijs L, et al. Fatal and nonfatal outcomes, incidence of hypertension, and BP changes in relation to urinary sodium excretion. JAMA. 2011;305:1777-1785.
    4)Graudal NA, Hubeck-Graudal T, Jurgens G. Effects of low-sodium diet vs. high-sodium diet on blood pressure, renin, aldosterone, catecholamines, cholesterol, and triglyceride (Cochrane Review). Am J Hypertens 2011;25:1-15.
    5)E.I. Ekinci, S. Clarke, M.C. Thomas, et al., Dietary Salt Intake and Mortality in Patients With Type 2 Diabetes, 34 Diabetes Care 703-09 (2011).
    6)Thomas MC, Moran J, Forsblom C, Harjutsalo V, Thorn L, Ahola A, Wadon J, Tolonen N, Saraheimo M, Gordin D, Groop PH; for the FinnDiane Study Group, The Association between Dietary Sodium Intake, ESRD, and All-Cause Mortality in Patients With Type 1 Diabetes. Diabetes Care. 2011
    Apr;34(4):861-866. Epub 2011 Feb 9.
    7)O’Donnell MJ, Yusuf S, Mente A, Gao P, Mann JF, Teo K, McQueen M, Sleight P, Sharma AM, Dans A, Probstfield J, Schmieder RE. Urinary sodium and potassium excretion and risk of cardiovascular events. JAMA. 2011 Nov 23; 306(20):2229-38.
    8)Maillot M, Drewnowski A. A Conflict between Nutritionally Adequate Diets and Meeting the 2010 Dietary Guidelines for Sodium. Am J Prev Med. 2012;42(2):174-179.