Is less salt an easy blood pressure fix?

Sodium is an electrolyte essential for several bodily processes, including muscle and nerve function as well as controlling fluid volume. However, too much sodium can cause our bodies to retain more fluid, increasing pressure in our blood vessels. High blood pressure can damage blood vessels over time, which can lead to heart attacks and strokes if left untreated. Excessive sodium can also put strain on the kidneys, which may eventually cause kidney failure. Those with kidney disease and high blood pressure are advised to limit their sodium consumption. But for the general population, how much sodium is too much?

The American Heart Association (AHA) and the USDA's American Dietary Guidelines currently recommend consuming less than 2,300 mg of sodium on a daily basis, and the AHA suggests moving toward 1,500 mg per day as an ideal amount. The average American eats much more than this recommendation: roughly 3,400 mg per day, over 70 percent of which comes from processed foods and eating at restaurants, according to the CDC. Globally, the estimated average intake is even higher at nearly 4,000 mg. Communities that consume greater than 5,000 mg of sodium on average (mostly in China) show a higher risk of cardiovascular events like strokes and heart attacks.

Debate over the health benefits of reducing salt in our diets
Scores of studies have investigated the effects of salt on blood pressure and cardiovascular health. Most have found that a reduction in sodium consumption decreases blood pressure by a modest amount in the general population, and by a larger amount (a drop of 4 to 8 mm Hg in systolic blood pressure) for people who already have hypertension. Patients can reduce their blood pressure even more by following the "Dietary Approaches to Stop Hypertension" or DASH diet (link provided below). In some cases, these dietary changes help improve a patient’s health to a level where blood pressure medications are not required.

Recent studies have challenged the notion that reducing sodium has protective benefits for the general population, and assert that sodium has a protective effect for cardiovascular disease. They maintain that there is a "J-shaped" relationship between sodium and cardiovascular health, meaning eating either too much or too little sodium increases risk of cardiovascular disease. The range suggested by these studies is 3,000 to 5,000 mg of sodium per day, which the global average happens to fall into. At least some of these studies have been conducted by researchers affiliated with organizations like ConAgra (processed food company).

More to the equation than just salt reduction
Salt works with several other electrolytes to maintain healthy fluid levels in the body, and researchers are discovering that increasing dietary potassium along with magnesium and calcium may be just as important as limiting sodium for reducing blood pressure. Also, salt can affect people differently, with age, body chemistry and genetics playing a role. For younger patients with efficient kidneys, consuming higher levels of sodium per day might not be a problem. But other patients might suffer dangerous health consequences from eating the same amount of salt.

Talk to your physician before making any dietary or medication changes. High blood pressure may not cause any symptoms but can cause damage over time, so regularly check your blood pressure.

Hypertension meds used to help body get rid of excess salt
Diuretics, sometimes called "water pills," help the kidneys get rid of unneeded water and salt. Used since the 1940's, they are often the safest and first-choice medication for hypertension. They can be prescribed as stand-alone drugs or in combination with other ingredients. Click drug name to read patient experiences for these diuretics taken to treat high blood pressure.

American Heart Association recommendations for dietary sodium They identify the "Salty Six" foods, which are six very popular foods that can add a lot of sodium to your diet: Pizza, Breads and Rolls, Sandwiches, Cold Cuts and Cured Meats, Soups, and Tacos/Burritos.

CDC recommendations for salt based on U.S. Dietary Guidelines: https://www.cdc.gov/salt/index.htm

World Health Organization recommendations: Salt reduction fact sheet

2015-2020 U.S. Dietary Guidelines: https://health.gov/dietaryguidelines/2015/guidelines/ These guidelines are about to undergo a revision, and many stakeholders have expressed their opinions about sodium recommendations. (See "Policy" section below.)

World Health Organization fact sheet on iodine deficiency: http://www.who.int/nutrition/topics/idd/en/

The Salt Institute has industry information, including maps of where salt is obtained, along with topics related to health, chemical, and agricultural uses for salt: http://www.saltinstitute.org (update 9/6/2019; effective March 2019, the Salt Institute has closed operations.)

Studies:
Large study review from 2014 describes various findings on the topic. Dietary Salt Intake and Hypertension. Electrolytes & Blood Pressure. Sung Kyu Ha, M.D.

High blood pressure: Sodium may not be the culprit. Medical News Today

Average salt consumption is safe for the heart: August 2018 Science Daily

J-Curve associated with sodium intake: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188229/

Study finds no j-curve associated with sodium intake: American Heart Association

Dietary Advice:
15 foods that help lower blood pressure: Medical News Today

10 ways to control high blood pressure without medication: Mayo Clinic

The DASH Diet: a flexible and balanced eating plan that helps create a heart-healthy eating style for life. The DASH eating plan requires no special foods and instead provides daily and weekly nutritional goals.

Policy and guidelines related to dietary salt recommendations under review:
The USDA's 2020-2025 Dietary Guidelines for Americans development process is under way. Dietary Guidelines provides food-based recommendations to promote health, help prevent diet-related chronic diseases, and meet nutrient needs. It is the cornerstone of federal nutrition policy and nutrition education activities. Committee member nominations will be accepted through October 6, 2018. Learn more at https://www.dietaryguidelines.gov/

Read and comment on the FDA Nutrition Innovation Strategy. As with the Dietary Guidelines, many stakeholders have expressed differing opinions about sodium recommendations. Comments about the FDA's initiative will be accepted through October 11, 2018.