You have probably heard this message loud and clear: eat less salt.
Table salt is made up of a chemical compound called sodium chloride. The sodium portion of salt is responsible for its health concerns. High sodium intake is linked to high blood pressure, which is known to cause strokes and heart attacks. The Dietary Guidelines for Americans from the US government recommend that adults eat no more than 2300 milligrams (mg) of sodium a day—about 1 teaspoon of salt. Furthermore, for about half of all Americans—those aged 51 years or older, African Americans of any age, and people with high blood pressure, diabetes, or chronic kidney disease—the recommended maximum intake of sodium is 1500 mg a day. Currently, in spite of these recommendations, US adults consume an average of 3400 mg of sodium a day.
In May 2013, the Institute of Medicine released a report discussing findings from a review of the current worldwide research on sodium intake. The main conclusions of the report were
There is good evidence that eating more than 2300 mg of sodium a day increases the risk of high blood pressure. This increased risk of high blood pressure translates to an increased risk of cardiovascular (heart) disease. Cardiovascular disease is linked to poor health outcomes over time, including stroke, heart attack, and death.
There is not enough evidence to say that eating less than 2300 mg of sodium a day affects cardiovascular disease outcomes (stroke, heart attack, or death) either positively or negatively for the general population. However, in specific groups of individuals, there may be a few exceptions.
In people with mid- to late-stage heart failure, 2 clinical trials have suggested that a very low-sodium diet (around 1850 mg a day) may have negative health effects.
In people with known cardiovascular disease, diabetes, or chronic kidney disease, there is some evidence that a diet of 1500 to 2300 mg of sodium a day may have negative health effects compared with higher-sodium diets. However, this evidence is not strong enough to say that these individuals should be treated differently than the general population.
The report has caused some confusion and controversy regarding what is a safe and acceptable level of salt in the diet. Some news outlets interpreted this report as saying there was no benefit to decreasing salt intake, which is not true.
Because most Americans consume more than 2300 mg of sodium a day, they should still aim to decrease their sodium intake to the current Dietary Guidelines for Americans goal of around 2300 mg a day to lower their risk of high blood pressure and cardiovascular disease. However, there is not enough evidence at this time that further decreasing sodium intake to 1500 mg a day has extra benefit for cardiovascular disease outcomes.
The Institute of Medicine called for more good-quality clinical research to be done on this topic but was not asked to make a specific recommendation for the ideal amount of sodium in the diet.
Eat salt in moderation. Most salt in the diet is “invisible” and is contained in processed and restaurant foods. Therefore, salt intake can be decreased by eating out less often (especially at fast-food restaurants) and eating less prepared or packaged foods. If you do eat out, you can ask to have your meal prepared with less salt. Reading labels on prepared foods to look for sodium content per serving also helps. It is generally healthier to cook using fresh foods rather than buying already prepared or packaged foods.
Institute of Medicine reporthttp://www.iom.edu/Reports/2013/Sodium-Intake-in-Populations-assessment-of-Evidence.aspx
Dietary Guidelines for Americans, 2010http://www.health.gov/dietaryguidelines/2010.asp
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Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Source: Strom BL, Yaktine AL, Oria M, eds. Sodium Intake in Populations: Assessment of Evidence. Washington, DC: National Academies Press; 2013.
Topic: Diet and Nutrition
Jin J, Sugerman DT. Salt in the Diet. JAMA. 2014;311(12):1265. doi:10.1001/jama.2014.90