Many of the 70 million adults with hypertension would like to avoid taking medication. One common recommendation to lower blood pressure without medication is to reduce the amount of sodium in your diet. Most of the sodium in the American diet comes from sodium chloride, commonly known as salt. Currently, the average American ingests 3,400 mg of salt every day.  Most raw foods have very little salt. Nearly all processed foods have added salt. One dramatic example is a 3½-ounce pickle has 1,208 mg of sodium. The same weight raw cucumber has only 2 mg of sodium.

Current recommendations are for everyone to eat less than 2,300 mg a day of sodium and people over age 51 or with high blood pressure to limit their sodium intake to 1,500 mg. About 90 percent of Americans consume more sodium than these guidelines. Although experts agree that 3,400 mg is too much sodium, how much to reduce your sodium is controversial.

Global studies have found countries with high sodium intake have more people with hypertension. Reduction of sodium below 1,500 mg a day reduces blood pressure by about 5 mm/Hg. In one study, patients with hypertension combined a DASH diet that is rich in fruits, vegetables and lean meat with sodium reduction. In this study, reducing the sodium from 3,300 mg a day to 2,400 mg a day lowered blood pressure by 2.2 mm/Hg. Reducing sodium intake from 3,300 mg to 1,500 mg lowered blood pressure by 6.8 mg/Hg. This illustrates the benefits of larger cuts in dietary sodium on blood pressure.

However, there is concern cutting back too much may be harmful. Most studies show lowering the blood pressure with reduced sodium also lowers your risk of dying from a heart attack. A few studies have found patients with the lowest sodium intake are at increased risk of dying from a heart attack.

In 2015 the USDA reviewed the current evidence. They concluded that all people should try to limit their sodium intake to 2,400 mg. They found cutting sodium to 1,500 provided additional benefit. Unfortunately, there is not good evidence on the risks versus benefits of more extreme cuts.

In summary, the average American eats too much salt. There is good evidence that reducing sodium reduces blood pressure and subsequently reduces your chance of a heart attack for daily sodium intakes as low as 1,500 mg. We do not know if more extreme cuts have further beneficial effects. This further supports eating foods that have not been processed.

Key References

1. Van Horn L: Dietary Sodium and Blood Pressure: How Low Should We Go?  Prog Cardiovasc Dis. 2015 Jul-Aug;58(1):61-8
2. Stolarz-Skrzypek K, Kuznetsova T, Thijs L, et al. Fatal and nonfatal outcomes, incidence of hypertension, and blood pressure changes in relation to urinary sodium excretion. 2011;305(17):1777-1785,
3. J. O’Donnell, S. Yusuf, A. Mente, et al: Urinary sodium and potassium excretion and risk of cardiovascular events. JAMA, 306 (20) (2011), pp. 2229–2238
4. USDA Scientific Report of the 2015 Dietary Guidelines Advisory Committee. http://health.gov/dietaryguidelines/2015-scientific-report/pdfs/scientific-report-of-the-2015-dietary-guidelines-advisory-committee.pdf