- Salt also known as “table salt” is chemically sodium chloride and chloride and is typically used as a seasoning and food additive prized for its flavor as well as for its function as a preservative, binder, and stabilizer.
- Table salt contains additives: iodine (it is “iodized”) to prevent iodine deficiency and calcium silicate to prevent clumping.
- Most Americans consume unhealthy amounts of sodium in their food, far exceeding public health recommendations and most of this excess comes from the addition of sodium during food processing not from the salt shaker.
The human body needs only a small amount of sodium, which is the principal ion of salt and is essential for life but on the other hand too much sodium in the diet can lead to high blood pressure, heart disease, and stroke. Most Americans consume at least 1.5 teaspoons of salt (or 3,500 mg of sodium per day, which contains far too more sodium than our bodies need. The Institute of Medicine (IOM) recommends that most healthy people should limit sodium to 1,500 mg of sodium per day, with an upper limit of 2,300 mg. But the average American eats closer to 3,600 mg each day, largely in processed foods.
There is a debate regarding just how concerned we need to be about watching the sodium in our diet. The 2014 Institute of Medicine (IOM) report stated there was insufficient evidence about the health benefits of reducing sodium below 2,300 mg. The 2014 American Heart Association (AHA) Sodium Advisory provided additional evidence to support a more aggressive sodium reduction and recommends that most of us should watch sodium and be aware of hidden sodium and strive for a low level of 1,500 mg of sodium per day. According to the the AHA’s 2020 Impact Goals this aggressive sodium restriction is recommended for the 69% of Americans with hypertension, all middle-aged and older adults, and all African-Americans. on the other hand, individuals who lose large volumes of sweat, such as competitive athletes and workers exposed to extreme heat (foundry workers, firemen) or those directed by the physician are excluded. Most recently, May 2016 the FDA has weighed in on lowered sodium and is asking food manufacturers and restaurants to reduce salt in their products -something way overdue. According to Dr. Thomas Frieden, Director of the Centers for Disease Control and Prevention, the evidence linking sodium intake with blood pressure “incontrovertible”.
- MedChefs tracks sodium since the uncontested facts show that for most Americans consume way too much sodium, and reduction of sodium can lower blood pressure. Hypertension is the most common common risk factor for stroke and is called the silent killer -so if you have not had your BP checked -don’t wait. Hypertension affects 40% of African-American men and women over age 20. Salt restriction lowers blood pressure.
Salt restriction: measurement matters
A report in 2014 from the New England Journal of Medicine by O’Donnell raised questions about our current population-wide sodium recommendations since cardiovascular risk was seen at both low as well as very high sodium intakes. The observational study was believed by many to draw its conclusions on faulty methods to assess daily 24 hour sodium intake based on a single urine sample obtained in the morning throughout the nearly 4 year of the study.
A more recent May, 2016 article published in the Lancet by Andrew Mente, McMaster University, Canada made headlines and rekindled the same controversy and again called into question the prevailing body of experimental and clinical evidence to lower sodium. The study claimed that the average sodium consumption for non-hypertensive Canadians was just fine at 3.5 to 5 grams per day and that reducing salt consumption less than 3 grams per day was dangerous and could be associated with increased risk of death or suffering a “major cardiovascular disease event.” The estimates of salt consumption, however were based on measurements of a single urinary sodium sample and was roundly criticized for faulty methodology. According to Dr. Mark Creager, president of the American Heart Association and director of the Heart and Vascular Center at Dartmouth-Hitchcock Medical Center,
“The large body of science clearly shows how excessive amounts of sodium in the American diet can cause high blood pressure, which can lead to disease and even death…this is a flawed study and you shouldn’t use it to inform yourself about how you’re going to eat.”
Considering all the evidence, many national and international organizations continue to believe that sodium intakes that exceed an approximate range of 1.5 to 2.3 g per day are harmful. Professor Francesco Cappuccio, head of the World Health Organization’s Collaborating Centre for Nutrition, attacked both the methods used in the Lancet for publishing the article and said,
“It is with disbelief that we should read such bad science published in The Lancet”
High quality studies on just how restrictive to be about sodium are lacking and the most controversial aspect is whether decreasing sodium intake improves outcomes. Numerous trials show that the limit of sodium intake can lead to reductions in BP. Long-term follow-up trials showed the remote effects of dietary sodium reduction up to 4 years with a 30% lower risk of a cardiovascular events. Both AHA and the US Dietary Guidelines took into account the high sodium levels in the available food supply and the current high levels of sodium consumption, and recognized that a reduction in sodium intake to 1500 mg/d was not easily achievable and thus made an interim recommendation of 2300 mg per day for the general population and less than 1500 for individuals with hypertension, African-Americans, and middle and older-aged Americans.
The highest level of medical evidence is the randomized clinical trial, and such studies showing salt reduction and clinical benefit are limited; however medical progress moves forward by consideration of the totality of the evidence that includes: the agreement that most Americans do consume too much salt mostly from processed foods and that lowering that amount does reduce BP and for many at risk middle aged Americans and especially some ethnic groups. Population-wide reduction in salt has resulted in predictions of roughly 9000 fewer deaths a year, from strokes and heart attacks in the United Kingdom (UK Food Standards Agency’s salt reduction programme undertaken between 2003 and 2010).
Much of the controversy about salt has been fueled by the salt and food industry, similar to the tobacco industry’s “war on science.” Despite limitations of clinical trials on sodium we as clinicians must connect the dots and make some educated assumptions. Medical evidence should always include the totality of evidence from randomized studies, meta-analysis, experimental and observational studies, and clinical experience. Analysts estimate that population-wide reductions in sodium could prevent more than 100,000 deaths annually. This is especially so for those at higher baseline risk such as those with known heart disease, prehypertension, hypertension, obesity, or type 2 diabetes.
Salt and blood pressure (BP)
Epidemiologic studies have shown that even prehypertension, or mild elevations of BP from 120/80 to 139/89 is a common worldwide condition affecting up to 30 to 50% of the studied populations and this is considered a cardiovascular risk factor (the recent SPRINT trial now suggests optimal systolic BP control for hypertensives maybe less than 120 mm Hg.)
- Lowering sodium intake to lower BP usually means less processed foods -that’s where the sodium is. Nearly 70 percent of US adults are at risk of developing health problems associated with salt consumption and those with higher risk of sodium related health risk deserve the more aggressive sodium restriction. Successful lifestyle intervention that includes less sodium can have a major public health impact since a reduction of only 2 mm of mercury in systolic BP -easily achievable by a little effort would be expected to reduce from stroke death rate by 6%, heart attacks by 4%, and the chance of dying from any cause by 3%.
Less sodium, more fruits, vegetables, whole grains and low-fat dairy foods as in the Dietary Approaches to Stop Hypertension (DASH) dietary pattern that is very similar to the AHA 2020 dietary pattern and is part of the Medchefs’ dietary filter. The DASH diet, which in addition to lower sodium is a dietary pattern rich in potassium and moderate (not extremely low) in sodium has many of the overall features considered so important for health. The DASH diet was specifically studied and shown to have meaningful blood pressure lowering effects. Check out new information on the MIND diet that incorporates the DASH sodium restriction and reduced risk of Alzheimer’s.
Much of the controversy about salt has been fueled by the salt and food industry, similar to the tobacco industry’s “war on science.” Despite limitations of clinical trials on sodium clinicians connect the dots and make some educated assumptions. Medical evidence should always include the totality of evidence from randomized studies, meta-analysis, experimental and observational studies, and clinical experience. Nutrition advice is no exception. Analysts estimate that population-wide reductions in sodium could prevent more than 100,000 deaths annually. This is especially so for those at higher baseline risk such as those with known heart disease, pre-hypertension, hypertension, obesity, or type 2 diabetes. According to Dr. Frieden, Director of the CDC, a decrease in sodium intake by as little as 400 mg per day could prevent 32,000 heart attacks and 20,000 strokes each year.
Hidden sources of sodium
Sodium is often hidden and found in the following: seasonings like soy sauce, teriyaki sauce and garlic or onion salt, most canned foods and some frozen foods, processed meats like ham, bacon, sausage and cold cuts, salted snack foods like chips and crackers, most restaurant and take-out foods, canned or dehydrated soups (like packaged noodle soup). Sodium is often hidden and reading labels is important. 75% of sodium we ingest in North America and Europe, does not come from a saltshaker but from packaged, ready-to-eat, prepared, or restaurant foods. In Asia most sodium is from soy sauce or is added at home. The addition of a bit of soy sauce is believed to boost the “unami” or savory flavor profile that is common to meat, cheese, and mushrooms. For those with chronic kidney disease use of salt substitutes may also be a problem since they are high in potassium so consult your doctor if you have kidney disease.
- According to the 2007-8 National Health and Nutrition Survey 2007-2008 the “top 10” food categories with the most sodium are not from foods considered fresh but typically come from store purchased items such as: bread, cold cuts and cured meats, pizza, poultry, soups, sandwiches, cheese, pasta mixed dishes, meat mixed dishes, and savory snacks (and the American or “Western diet” includes a large proportion of fast
Kosher salt or sea salt?
Compared to common table salt, kosher salt is a coarser-grain (flaky crystals) and is preferred by chefs since the large grains are easier to use and distribute easily and cling well to food surfaces. If a recipe calls for 2 tablespoons of kosher salt, use 1 tablespoon of table salt instead. If you’re converting the other way, use twice as much kosher salt as table salt. The finer crystals of table salt are considered “saltier” than kosher or sea salt. 1 teaspoon of table Salt, Sea Salt, Kosher Salt, Fleur de Sel, Sel Gris, Hawaiian Sea Salt, or the purist Himalayan Salt are all equivalent in sodium amount -each contain 2,325 mg of sodium per teaspoon.
Soy and MSG
Soy Sauce is very high in sodium: one individual packet (8.9g) has 502 mg or about 1/3 of the amount recommended daily sodium consumption (the current total daily requirement for most Americans is 1500mg). Kikkoman regular soy sauce has 920 mg. of sodium for just one tablespoon and the reduced or “lite” sodium version has 575 mg. per tablespoon. San-J Tamari has similar numbers: the regular is 960 mg. for one tablespoon while the reduced sodium version has 700 mg. per tablespoon.
On the other hand, monosodium glutamate (MSG) contrary to what many have believed, is not high in sodium and is only about 1/3 the amount of sodium as sodium chloride or table salt. MSG is not confined to Asian cuisine and is also a very popular seasoning in North America, where it is sold under the brand name Accent. The American Medical Association’s Council on Scientific Affairs and the National Academy of Sciences have determined that MSG, at current consumption levels, is safe as a food ingredient for the public. Asian cooks often use MSG or monosodium glutamate (the salt of glutamatic acid, a non-essential amino acid) for its flavor enhancing properties.
Sodium and diabetes?
Type 2 diabetics who eat a diet high in salt have twice the risk of developing cardiovascular disease as those who consume less sodium. A recent 8-year population study found that people with diabetes who consumed an average of 5.9 grams of sodium compared to 2.8 grams of sodium daily had double the risk of developing heart disease and this risk jumped nearly 10-fold for those with poorly controlled type 2 diabetes. (Horiakwa, C et al. Dietary Sodium Intake and Incidence of Diabetes Complications in Japanese Patients with Type 2 Diabetes – Analysis of the Japan Diabetes Complications Study (JDCS). The Journal of Clinical Endocrinology & Metabolism, 2014).
- Type 2 diabetes is usually associated with older age adults, obesity and physical inactivity, family history of type 2 diabetes, or a personal history of gestational diabetes. According to the U.S. Centers for Disease Control and Prevention (CDC) there are about 29 million Americans with diabetes and death from heart disease is at a rate 1.7 times higher than for those without diabetes. In 2010, about 1.9 million new cases of diabetes were diagnosed in people aged 20 years or older and if the current trends continue, 1 of 3 U.S. adults will have diabetes by 2050. Unfortunately, the numbers are changing and while type 2 diabetes was once believed to be a disorder exclusively in adults in the last two decades it is increasingly more common in obese adolescents. People with prediabetes (a condition that is much more common than type 2 diabetes) who lose 5%–7% of body weight and get at least 150 minutes a week of moderate physical activity can reduce the risk of developing type 2 diabetes by 58%.
“The findings (on dietary sodium) are very important from a public health point of view and people with diabetes need to track more than just carbohydrates (and consider sodium) when managing their daily diet” according to Dr. Prakash Deedwania, Chief of Cardiology for the Veterans Administration Central California Health Care System
Iodine deficiency can cause low thyroid disease (hypothyroidism) and lead to an enlarged thyroid gland (or goiter). Iodine is an essential part of diet since the body does not make iodine. Iodine deficiency related to dietary deficiency is common in some parts of the world and represents the greatest preventable cause of brain damage in children (mental retardation). Iodine deficiency constitutes a public-health concern worldwide particularly for pregnant women and young children. The World Health Organization (WHO) has determined that the cornerstone for elimination of iodine deficiency disorders (IDD) is iodization (iodized table salt means that iodine has been added). The lowest prevalence of iodine deficiency is found in North America, where the proportion of households consuming iodized salt is the highest in the world (90%).
- The highest prevalence of iodine deficiency is in the European Region, where the proportion of households consuming iodized salt is the lowest (27%). In the US it makes more health sense to reduce salt and get iodine from foods such as: ocean-caught or farmed fish and shellfish which are naturally rich in iodine and sources such as cow’s milk, cheese, seaweed (including dulce, nori), yogurt, eggs, and soy milk or multivitamin pills that also contain minerals usually provide 150 micrograms of iodine.
Most of us take in way too much sodium -and we never even lift the salt shaker. in fact, nine in ten US adults and children consume too much sodium. The majority of Americans’ daily sodium intake comes from processed foods, including processed meats and poultry, soups, and sandwiches. Prehypertension affects one-quarter of Americans and hypertension is present in most seniors and can be even more prevalent in some ethnic groups including African-Americans -so get BP checked regularly, read labels, and lower that sodium! The FDA released a draft guideline proposal (June, 2016) for food companies to voluntarily reduce sodium in processed and restaurant foods. This will be important since it will enable consumers to make more informed choices. Medchefs heartily endorses this long awaited national effort to reduce sodium levels in the US food supply.
Cook NR, et al. Lower levels of sodium intake and reduced cardiovascular risk. Circulation 2014;129:981-989
Mozaffarian, D et al. Global Sodium Consumption and Death from Cardiovascular Causes.
Cogswell, ME et al. Dietary Sodium and Cardiovascular Disease Risk — Measurement Matters. N Engl J Med June 1, 2016DOI: 10.1056/NEJMsb1607161
Frieden, TR. viewpoint: Sodium Reduction -Saving Lives by Putting Choice Into Consumers’ Hands. JAMA. 2016; 316: 579-80
Sodium reduction. FDA website. http://www.fda.gov/Food/IngredientsPackagingLabeling/foodadditivesIngredients/ucm253316.htm. Posted June 1, 2016