Shaking Out Sodium Replacement Facts

By Christina Fitzgerald, M.S., R.D., L.D.N. Comments
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Recent estimations suggest that one out of three adults in the United States has high blood pressure. Unfortunately, high blood pressure is known as “the silent killer,” since an adult may be asymptomatic for years and then have a massive heart attack. Most Americans consume between 3,000 to 4,000 mg of sodium daily, which is well above the daily recommended 2,300 mg of sodium.

Sodium’s health implications
Cardiovascular disease (CVD) is the current leading cause of death worldwide. Among the risk factors for CVD, raised blood pressure accounts for 49% of the cases. Some individuals with high blood pressure do not have a correlation between increasing pressure and salt intake. These individuals are known as salt-resistant hypertensives. However, 30% to 50% of those with high blood pressure are salt-sensitive hypertensives.
Risk factors for developing high blood pressure include: males older than 45 and females over 55, African American ancestry, excessive salt consumption, physical inactivity, and alcohol consumption. Commonalities of salt-sensitive hypertensives include: black race, obesity, advanced age, diabetes and renal dysfunction.
The average American adult should aim to eat less than 2,300 mg of salt per day. However, those at higher risk, including African Americans and middle to older aged adults, may need as low as 1,500 mg salt per day.
Most sodium is consumed in the form of sodium chloride, or table salt, but there are a wide variety of common food ingredients that also contain sodium, such as soy sauce and MSG.


Salt substitutes
Salt substitutes can be an easier way to limit sodium consumption; however, they are not safe for all to consume. A majority of salt substitutes utilize potassium chloride in place of sodium chloride. Other sodium-containing ingredients, such as sodium bicarbonate, can be substituted by potassium-based ingredients, such as potassium bicarbonate. A person with chronic kidney disease, for example, has difficulty filtering excessive potassium (greater than 2,000 mg) from the body, and consuming a salt substitute poses a deadly threat.
However, emerging evidence demonstrates that high salt intake may be balanced out by an increase in potassium intake. Some population studies even indicate an inverse relationship between dietary potassium and blood pressure. The DASH diet (Dietary Approaches to Stop Hypertension) requires twice the average number of daily servings of fruits and vegetables, so an individual’s potassium intake will greatly increase toward the goal of 90 mmol daily (90 mEq daily). It’s estimated that consuming a salt to potassium ratio of 1:1 will lower an individual’s systolic blood pressure by 3.4 mm Hg.
Another mineral that might serve as a sodium substitute is magnesium in the form of magnesium salts such as magnesium sulfate. Although excess magnesium can inhibit bone calcification, toxicity is not common as healthy kidneys are very efficient at excreting magnesium from the body. However, taking excessive supplements or ingesting excessive magnesium sulfate can be a concern, especially for those with kidney disease.  For both men and women ages 15 to 70 years, the tolerable upper intake level is 350 mg per day.
Another common substitutes is “lite” salt (low-sodium salt). This enhancer still contains sodium and is often a blend of sodium chloride and potassium chloride. In an otherwise healthy individual, a salt substitute can be a useful tool in low-sodium cooking, as it not only decreases the sodium, but also increases the individual’s potassium intake, which could be protective and preventative in heart disease.
While not a salt substitute per se, the flavor enhancer monosodium glutamate (MSG) is a common additive considered to bring out the fifth taste, umami. Heightened umami provided by certain amino acids can provide an alternative for a salty taste. Glutamate is an amino acid found in all protein-containing foods, such as cheese, milk, mushrooms, meat and fish. Glutamate is also produced in the body and is necessary for normal metabolism and brain function. MSG is the sodium salt of glutamate. MSG is mistakenly thought of as being high in sodium. However, MSG contains only one-third the amount of sodium as table salt. There are questions as to whether certain individuals have a food sensitivity to glutamates.
Another amino-acid-based salt substitute is L-lysine. L-lysine is an essential amino acid that is necessary for a person’s health but cannot be made in the body. In a salt substitute, L-lysine is blended with potassium to mask the bitter aftertaste common with potassium chloride. Currently, there is no tolerable upper intake level set for L-lysine. However, it may interact with certain medications, so any person utilizing this substitute should discuss their usage with a health care provider. 

Christina Fitzgerald, M.S., R.D., L.D.N., specializes in pre- and postpartum, as well as pediatric, nutrition. She is the owner of the private nutrition practice, Nourished Nutrition and Wellness, based in Chicago, and can be reached at christina@nourishedliving.com .

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