Salt: The Forgotten Killer

A UM hypertension expert discusses the health risks of sodium

One of the University of Maryland Medical Center’s experts on hypertension, Dr. Stephen Havas, recently spoke at a news conference in Washington, D.C., when the Center for Science in the Public Interest released a report that says high-salt diets cause 150,000 premature deaths in the U.S. each year and that urgent action is required from federal health authorities to reduce Americans' sodium consumption.

 The report identifies trends in sodium consumption, highlights some of the processed foods and restaurant meals that have the highest sodium content, and makes policy recommendations designed to reduce Americans' sodium intake. CSPI also announced a lawsuit aimed at ending the Food and Drug Administration’s 20-year-long delay on finalizing salt’s regulatory status.

Stephen Havas, M.D., a professor of epidemiology, preventive medicine, and medicine at the University of Maryland School of Medicine, also represents the American Public Health Association (APHA) on an expert committee that advises the National Institutes of Health about the prevention and control of hypertension.  He was the author of a resolution adopted by APHA calling for a 50 percent reduction in salt in processed and restaurant food over the next 10 years.  Dr. Havas said that reduction would save 150,000 lives a year from strokes, heart attacks and other illnesses.

Below, Dr. Havas answers questions about the health risks of sodium and offers advice on lowering your salt intake.

What conclusion has the medical community come to regarding high-sodium diets?

The medical community has reached a consensus that diets high in sodium are a major cause of high blood pressure as well as pre-hypertension, or blood pressure just short of high blood pressure. This significantly increases the risk of having a heart attack or stroke.

About how many Americans suffer from high blood pressure and pre-hypertension?

Today roughly 65 million Americans have hypertension, also known as high blood pressure, and another 45 million have pre-hypertension.  Blood pressures greater                  than 140/90 are considered hypertension, while those between 120/80 and 140/90 are considered to be pre-hypertension.  Ninety percent of Americans will ultimately develop hypertension unless preventive actions are taken.

 Looking at the bigger picture, each year 700,000 Americans die of heart disease and more than 160,000 die of stroke. Blood pressure levels greater than 120/80 are a major cause of these diseases. The risks of heart attack, congestive heart failure, stroke, and end-stage kidney disease increase progressively as blood pressure levels rise above normal levels.

Unfortunately, a lifetime of eating too much salt is putting Americans’ lives in jeopardy.  

 And sodium is a major cause of high blood pressure, more so than obesity or other factors?

 Although obesity and other factors also contribute to hypertension, excessive sodium intake is one of the most important causes and the cause most amenable to a public health solution. There is a clear relationship between habitual sodium intake and blood pressure.  A landmark randomized clinical trial, the Dietary Approaches to Stop Hypertension (DASH) Sodium study demonstrated this. The study randomized participants either to the DASH eating plan, which is high in fruits, vegetables and fiber and low in fat, or to the usual American diet.

Individuals ate their respective diets at three sodium levels: high (3,300 mg), intermediate (2,400 mg) and low (1,500 mg). A teaspoon of salt contains roughly 2,400 mg of sodium. Reducing sodium from the high level to the low level lowered blood pressure by 8.3/4.4 mm Hg in people with high blood pressure and by 5.6/2.8 mm HG in people with normal blood pressure.

Blood pressure reductions such as those would have major impacts on mortality as well as on the occurrence of disabling disease. This could result in fewer deaths from stroke and coronary heart disease.

How much sodium does the average American consume on a daily basis?

Unfortunately, American adults ingest nearly 4,000 mg of sodium daily on average, far exceeding current recommendations.

 What are the current recommendations?

The Institute of Medicine of the National Academy of Sciences, the Department of Agriculture, the Department of Health and Human Services and the World Health Organization have all supported lowering daily sodium intake to no more than 2,400 mg and some of those agencies have said that many people should consume less than 1,500 mg.

 Adults who are middle-aged, elderly, already have hypertension or prehypertension, or who have a family history of hypertension should consume less than 1,500 mg.

  What is the main culprit of the high salt content in foods?

Roughly 75 percent of the daily sodium intake of the U.S. population comes from salt in processed and restaurant foods. Only 10 percent comes from foods’ natural content. That makes it extremely difficult for consumers to follow a low-sodium diet.

 Why does that make it so difficult?

Because many canned and frozen foods contain 1,000 mg or more of sodium in an eight-ounce serving. Consumers must read food labels very carefully to select lower sodium products. Often such products are difficult to find or cost more.

 Restaurant meals, which are not labeled, often contain 3,000 mg of sodium or more, added without the consumer’s knowledge.  

Given those challenges, how can people reduce their salt intake? What are some good tips people can follow to consume less sodium on a daily basis

• Making recipes from scratch will allow you to avoid much of the salt in your diet.



• If you do buy any processed foods in the supermarket, select ones that are the lowest in sodium. Products that are labeled “sodium free” or ones that have less than 100 mg per serving are the best.



• When you go to a restaurant, ask them to prepare your food without adding any salt and to use other spices instead. Most restaurants will agree to do this or will suggest items for which they will do this.



• Avoid salting your food.



• Use spices other than salt when cooking. Examples include pepper, basil, thyme, garlic.



• Choose snacks low in sodium like fruits and vegetables. Avoid salty snacks such as pretzels and potato chips.