Thursday, December 10, 2015

Take it with a grain of salt! .... or not?

Everybody consumes salt on a daily basis. It is present in most of our food, either naturally (such as in meats or vegetables), as an added substance for flavour, or as a preservative (such as in cheese, bacon, canned foods, and most convenience foods). The main sources of salt in our diet are bread and cereal products, meat products and milk and dairy products (Buss & Robertson, 1973), next to the use of table salt. But what is salt?

     Common salt is a mineral that consists out of 2 elements (and sometimes some trace elements): sodium (Na) and chloride (Cl). Normally, salt crystals are translucent but appear to be white and are cubic in shape. If table salt contains e.g. impurities or added elements, it may have a different shade of white such as a white with a pink or blue hue.

Source: salt-91539_960_720.jpg


     Saltiness is one of the five human taste sensations (next to sweetness, sourness, bitterness and umami) and therefore salt is often used as a way to improve the taste of a food. However, salt does more than just make your food taste more delicious: it is a key element for our body to function. Sodium regulates both your blood flow and pressure (due to its role in osmosis and fluid balance), and it helps transmit the electrical signals between your nerves and muscle fibers. Chloride on the other hand, aids in your digestion (see: https://www.nlm.nih.gov/medlineplus/sodium.html) Consuming enough salt is crucial in order to replenish these nutrients and to keep you healthy.


     You could thus state that salt is good for you, and should be a part of the things we consume on a daily basis. However, there is also a downside to eating too much salt. Firstly, when you consume too much sodium your body retains more water, as your kidneys want to maintain a healthy potassium/sodium/water ratio (i.e. more sodium leads to a need of more water to retain the ratio). If you retain more water, you may suffer from edema (swelling of body parts, commonly your legs or ankles), and more fluid equals more blood. More blood in your arteries and veins causes them to stiffen over time, which can lead to high blood pressure and hypertension. Furthermore, eating lots of salt is likely to make you thirsty and due to the need to balance the electrolyte ratio, you thus should drink more. But if you don’t drink enough you can suffer from dehydration, causing nausea and headaches amongst others. Additionally, it can have a negative effect on appearance too: retaining more water (as your body is trying to balance the electrolyte ratio) can cause you to swell up, making your face puffy, adding volume to the bags under your eyes, and cause weight gain. And last but certainly not least: too much salt can stress your abdominal wall and eventually may play a role in causing stomach ulcers or even cancer (AHA, 2014b).


     So how much salt should you eat? The World Health Organization recommends that adults should consume less than 2,000 mg of sodium, equivalent to 5 grams of salt per day (World Health Organization (WHO), 2013). The American Heart Association (AHA) even chose to recommend that we should eat less than 1,500 mg/day of sodium as of 2010 (AHA, 2014a). Table salt contains approximately 40% sodium by weight, so a 6 g serving (1 teaspoon) contains around 2,300 mg of sodium. This means that recommendations are to consume less than 1 teaspoon (WHO recommendations) or less than 2/3 of 1 teaspoon (AHA recommendations) of salt a day. As you may have guessed: many of us do not manage to meet this recommendation. In the USA, only 18.8% of adults consumed <2,300 mg/day of sodium, and only 5.5% ≤1,500 mg/day (DeHoon, 2010). This is most likely due to the high level of sodium in many processed foods, as well as the high level of sodium in restaurant foods (Centers for Disease Control and Prevention (CDC), 2014). And consuming too much sodium can have a very negative effect on your health. 

     In a first attempt to better inform the general population of high-sodium foods, the AHA launched a campaign called the ‘salty six’ to increase awareness for 6 high-sodium foods that may go unnoticed as they don’t always taste very salty. These 6 commonly used products include breads and rolls, pre-made sandwiches, soups and cured meats. In another effort to better inform the general American public, New York City has a new regulation going into effect this week!

     NYC decided in September of this year to make it mandatory for restaurants to mark dishes on their menus that exceeded the daily-recommended sodium intake (Durando, 2015). New York is the first U.S. city with such a requirement, as a reaction to the pressure by officials and experts to urge Americans to eat healthier increases (Peltz, 2015). This applies to all types of dishes, ranging from salads and sandwiches, to stews or pies. If a dish contains more than 2,300mg of sodium, restaurants now have to display a saltshaker-symbol next to it. The regulation will affect “an estimated 10% of menu items at the New York City outlets of chains with at least 15 outlets nationwide, and about 1/3 of the restaurant traffic in the city” ((Durando, 2015; Peltz, 2015). Hopefully, as a result, people will chose a dish that contains less salt, in order to make a healthier choice. However, consuming two dishes of medium salt levels, or simply consuming other dishes (breakfast, lunch, dinner) during the day that also contain salt can still cause people to consume too much salt, while unaware of the fact that they are doing so. Actually, some experts have urged the city to set the warning limit as low as 500 mg, in order to really increase awareness and the likelihood of people actually staying under the daily recommended amount (Peltz, 2015).

NYC's sodium warning label. Source: sodium-warning-label-v2.jpg


     Do you think you’re eating a healthy amount of salt? It probably wouldn't hurt to pay attention to your salt intake, read a food label here and there when you’re buying (especially prepackaged/canned) foods, and for example try to limit the amount of salt you add when cooking. You might be surprised to see how much salt is added to some products, and by choosing a similar lower-salt option you could be helping your own body to be as healthy as possible. Especially since the addition of salt isn’t just something that occurs in America, it happens in Belgium too.


     To conclude: a practical example close to home. Belgium is a country big on their cheeses, and rightly so (they are delicious!). However, dairy products are one of the product types that more often than not contains added salts. Two random cheeses at the supermarket contained 2300mg sodium /100g of cheese, and 607mg sodium/100g of cheese.  A slice of cheese that you would put on toast/bread is about 20 grams. So if you would consume 2 of those slices you would have consumed about 920mg sodium (about 60% of daily recommendation of the AHA) or 243mg sodium respectively (about 16% of the daily recommendation of the AHA), excluding the sodium contained in the bread. Obviously one of these cheeses would thus be a much healthier choice, when considering salt content, especially bearing in mind the fact that additional salt would be consumed with other product throughout the day. So what will you do? Are you taking this all with a grain of salt, or not?


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PS: For those who are interested to see if their salt knowledge is really up to date, test yourself here: http://sodiumbreakup.heart.org/test-your-knowledge/

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Maartje Mulders is a PhD Student at the Center for Social and Cultural Psychology at ULB (Université Libre de Bruxelles)



References:


American Heart Association (AHA). (2014a, Mai 1). Frequently Asked Questions (FAQs) About Sodium. Retrieved from: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Frequently-Asked-Questions-FAQs-AboutSodium_UCM_306840_Article.jsp#.VmfvZYRzeS0.

American Health Association. (2014b). Retrieved from: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/The-Effects-of-Excess-Sodium-Infographic_UCM_454384_SubHomePage.jsp

Buss, David; Robertson, Jean (1973). Manual of Nutrition. Her Majesty's Stationery Office. pp. 37–38.

Centers for Disease Control and Prevention. (2014, August 21). Sodium and Food Sources. Retrieved from: http://www.cdc.gov/salt/food.htm

Durando, J. (2015, December 1). New York City's salt warning on menus to take effect. USA Today. Retrieved from: http://www.usatoday.com/story/news/nation-now/2015/11/30/new-york-city-salt-warning/76563862/

Kuklina, E.V. Morbidity and Mortality Weekly Report. (2010, June 25). 59, 746-749. Retrieved from: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5924a4.htm


Peltz, J. (2015, September 9). NYC to require salt warnings on menus. USA today. Retrieved from: http://www.usatoday.com/story/money/business/2015/09/09/nyc-salt-warnings/71936828/


World Health Organization. (2013, January 31). WHO issues new guidance on dietary salt and potassium. Retrieved from: http://www.who.int/mediacentre/news/notes/2013/salt_potassium_20130131/en/).

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