Lower the Salt, and the Blood Pressure Will Follow

Michael A. Weber, MD; Daniel T. Lackland, DrPH


May 06, 2014

This feature requires the newest version of Flash. You can download it here.

Hypertension Is a Global Problem

Michael A. Weber, MD: Hello. I am Dr. Michael Weber, Editor of the Journal of Clinical Hypertension. Welcome to this edition of Hypertension Focus. I'm delighted today to be welcoming a good friend and colleague, Dr. Dan Lackland from the University of South Carolina, and to be talking about a very important subject: salt.

Before we get into a discussion of salt, an exciting thing has happened to our journal. The World Hypertension League (and you are the President-Elect and very much involved in its activities) has formed a relationship with the Journal of Clinical Hypertension, and it is now going to be the official journal of the World Hypertension League.

Can you give us a very quick rundown on what the World Hypertension League is doing?

Daniel T. Lackland, DrPH: We are excited about this relationship, because we know that about 1 billion people around the [globe] are hypertensive. The World Hypertension League focuses on all of those people by organizing a network of all the different hypertension societies from around the [world].

Dr. Weber: It doesn't matter what country in the world you live in -- you are under the umbrella of the World Hypertension League?

Dr. Lackland: Yes, and from what we have seen, there is no country or society or population in the world that is not burdened by hypertension.

Dr. Weber: Each country has its own unique and difficult set of circumstances, even the United States. Speaking on behalf of the Journal, we are excited about working with you and getting the message out around the world.

The Number-One Issue in Hypertension

Dr. Weber: Everyone knows that eating too much salt is not good for you. It raises your blood pressure. Why is salt the number-one issue for the World Hypertension League?

Dr. Lackland: In a sense, it's because we have all of these different societies, and we know that for just about everyone, if you increase your salt intake, it's directly associated with blood pressure. In the World Hypertension League, for a global approach, we can address the issue of lowering salt intake and also lowering blood pressure as a major change that everybody can achieve.

Dr. Weber: That is critical. We just published the statement by the World Hypertension League in collaboration with the International Society of Hypertension, giving a lot of information about salt and the need for policies.[1] But let's get down to a couple of controversial areas.

Many of us were surprised when the Institute of Medicine (IOM) -- which is regarded as a pretty authoritative organization here in the United States -- seemed a little reluctant to make a statement on salt. What was that about?

Dr. Lackland: It's probably about several things. In one sense, we know that if you increase salt, you increase blood pressure, and therefore you increase risk. We have good evidence for that in every population.

Where there is a little less consensus is exactly how much you have to reduce salt, and where do you reduce salt? The IOM said that they didn't feel that the evidence was there. Some of us are not as certain about that, but they were looking for what we don't have: concrete studies that have shown the exact level of benefit in salt reduction.

Dr. Weber: That is a shame because, as in so many areas of medicine, we look for evidence and it's not always there, and yet we know there is a problem and we have to do something. We have to give the information and advice to practitioners.

Is the Harm Overstated?

Dr. Weber: A couple of people -- Dr. Michael Alderman[2] here in the United States, and Dr. Jan Staessen in Europe -- have argued that are we overdoing our concern about salt. Is salt, in fact, associated with all the risks that we blame it for, and mightn't it be helpful for some people? Is there anything to that argument?

Dr. Lackland: Certainly salt is essential, but the amounts that we ingest are hazardous and are raising our blood pressures. They don't have the evidence either to say that salt isn't hazardous. We think that we do have good evidence, because we can show that reducing salt reduces blood pressure, stroke, and other hypertension-related outcomes.

Dr. Weber: One of the problems, Dan, with what we might call "healthy diets" -- fresh fruit, fresh produce, foods that are not salty, if possible fresh food rather than preserved or processed foods -- is that they tend to be more expensive. So, particularly for people who are not affluent enough to be able to just pick and choose whatever foods they would like, what advice can we give them?

Dr. Lackland: We emphasize the importance of lowering blood pressure with fresh fruits and vegetables, and lower salt intake. By doing that, we are now treating our blood pressure. The fact that you just brought out is very important, and it is something that we want the World Hypertension League to do -- to get the information out to healthcare providers and to the public that salt does raise your blood pressure, so let's get the salt intake down.

The other piece that we have to talk about is the salt in processed foods that is already there. That needs to be emphasized.

Targeting Processed Foods

Dr. Weber: You're absolutely right, Dan. One of our important collaborators is Dr. Graham MacGregor from the United Kingdom, who is a passionate advocate for reducing salt. He has come up with an idea -- maybe other people have as well -- that the solution to the problem is going to come more as a matter of policy from the government rather than a spontaneous demand from people. As I understand it, Graham has convinced the British government to require reductions in the amount of salt in processed foods.[3]

Dr. Lackland: Correct; they are working directly with industry. And in some cases, it is a cooperative effort, recognizing that in lowering blood pressure by reducing salt in these foods, you are now selling a safer product. You are producing a safer product that has a benefit in that you are lowering blood pressure, and they have been very successful. Again, 80% of our salt intake is coming from processed foods and restaurant-prepared foods.

Dr. Weber: That is absolutely the right target. If you abruptly reduce salt, people will get very upset and say that their food has lost all of its flavor.

Dr. Lackland: That's true.

Dr. Weber: It has to be an incremental change each year over several years, until we get down to the right amount.

Dr. Lackland: Correct.

How Much Is Too Much?

Dr. Weber: Just roughly, Dan, for people who like facts and figures, what is the ideal sodium chloride intake for an average person?

Dr. Lackland: Many would say to aim for less than 1500 mg daily. That is what people are focusing on.

Dr. Weber: So, 1500 mg of sodium is roughly 5 g of salt; is that right? [Editor's note: 5 g of salt contains approximately 2300 mg of sodium; 1500 mg of sodium equates to approximately 3.8 g salt.]

Dr. Lackland: That's right.

Dr. Weber: What are people, in fact, eating? It must be some multiple of that.

Dr. Lackland: It's different in different populations and different cultures. Many people are getting a week's quota of the recommended salt intake with a single meal, and they are unaware of it. We have looked at the salt content of traditional meals. We would show perhaps a hamburger and ask people to guess the amount of salt it contains, and sometimes it is a week's quota of salt.

Dr. Weber: That is a sobering thought, and it clearly emphasizes how much work has to be done in every country of the world, including here in the United States.

Dr. Lackland: Yes.

Dr. Weber: It has been my pleasure to talk with Dan Lackland, who is President-Elect of the World Hypertension League and Deputy Editor of the Journal of Clinical Hypertension. Dan, I am looking forward to this wonderful collaboration between the Journal and the World Hypertension League. Hypertension is a global issue, and we are very excited about working together to see what we can do to resolve it.

Dr. Lackland: Absolutely.

Dr. Weber: Thank you all for joining us.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.