Salt, Sodium, and Blood Pressure: Just The Facts!

“Salt will raise your blood pressure and kill you! Throw away that shaker!”

“Hey, salt is not too bad! In fact, if you cut down too much, you will die early!”

The general public is losing confidence. Coffee is good for you, coffee is bad for you.  Fat will kill you, fat will liberate you. Every day, newspapers, magazines, the TV, all of them scream at us with contradictory health messages. It helps sales, but undercuts the credibility of the healthcare profession and the media.

So what is the deal?

As is often the case, the truth probably lies somewhere in the middle.

Science is an ever-changing field. New discoveries are made, and old thinking discarded. That is a sign of progress. After all, the earth was flat, till we discovered that it was really round.

So what should the average person do?

Evaluating the evidence behind various claims is a good way to start.

What exactly is salt?

Table salt is chemically sodium chloride (NaCl).

Scientific studies and professional agency recommendations often deal with sodium, rather than salt. To put their findings in perspective, salt is 40% sodium and 60% chloride.

One teaspoon of salt has approximately 2300 mg (milligrams) of sodium.

So what do the various agencies advise us to do?

American Heart Association (AHA)

In 2010, the AHA changed its advice, and now says that we should consume less than 1500 mg of sodium a day. This is less than a teaspoon of salt.

It does, however, make some exceptions.

Competitive athletes lose a lot of sodium in sweat, and need a higher salt intake. So do workers who face high degrees of heat, such as firefighters and foundry workers.

Finally, if your healthcare provider has given you different instructions about salt intake, the AHA says you should follow those.

WHO

The World Health Organization recommends a daily sodium intake of less than 2000 mg.

Dietary Guidelines for Americans

Their current advice is to limit daily sodium intake to less than 2300 mg (one teaspoon).

How much do we really eat?

The average American consumes 3300-3400 mg sodium every day. That equals about one-and-a-half teaspoons of table salt daily.

Institute of Medicine (IOM)

This institute was established in 1970 under the charter of the National Academy of Sciences. It serves as an adviser to the nation to improve health. It provides independent, objective, evidence-based advice to policy makers, health professionals, and the public.

There is evidence for the health benefits of reducing dietary salt intake. However, recent data indicate that low sodium intake may carry risk, too.

As such, the Centers for Disease Control and Prevention (CDC) asked the IOM to examine this recent data and then recommend population-based strategies for sodium intake.

In May 2013, the IOM issued its report, which said that:

• The newer studies had problems with the methods they used.
• These studies also suffered from quality issues.
• In spite of this, there is evidence of a link between high sodium intake and the risk of cardiovascular disease.
• The available evidence supports population-based efforts to reduce excessive sodium intake in the diet.
• There is not enough good-quality evidence to support the reduction of dietary sodium intake to 1500 mg or below.

More recent data

The PURE study was published in the New England Journal of Medicine in August 2014 http://goo.gl/X1Xxo5. The investigators studied more than 102, 000 people from 18 countries. They found that:

• 
• Blood pressure went up with increased dietary sodium intake.
• The systolic BP (top number) increased by an average of 2 mm Hg (millimeters of mercury) with a 1 g increase in sodium intake a day. The diastolic (lower number) went up by 0.8 mm Hg.
• The rise in BP with higher sodium intake was more marked in those people who already had high BP to begin with.
• Older people had a higher rise in BP with increasing dietary sodium

Death rates

The same issue of the New England Journal of Medicine had another article about sodium intake, high BP and also death rates http://goo.gl/iDYLBD.

The findings in this study were as follows:

• People who had sodium intakes of 3-6 g daily had a lower risk of death and cardiovascular events than those whose intake was higher than 6 g a day.
• This risk was even higher in patients who already had high BP to begin with.
• Interestingly, however, people whose sodium intake was below 3 g daily also had a higher risk of death and cardiovascular events than those with an intake between 3-6 g daily.

Problems with the PURE study

This was not a randomized, controlled trial, which tends to produce more reliable conclusions. It was an observational study, and data from such studies are often less reliable.

AHA stance

The AHA does not agree with the conclusions of the IOM report, or the PURE study, citing methodological problems with the studies which have been evaluated. The heart association stands by its guideline of reducing daily sodium intake to below 1500 mg.

Doctors disagree; what should the patient do?

• In general, most experts agree that the patient should follow the specific advice of his or her healthcare provider, who understands the complexities and details of the patient’s entire health situation.
• Most experts also agree that excessive salt consumption is not a good idea.
• 
• In general, high salt intake tends to raise BP.
• If you are an older individual, or already have high BP, it is likely that cutting down on salt will help you.
• If you have uncontrolled high BP, it is possible that high salt intake is causing or worsening your problem.

How low to go on salt?

Talk to your doctor!               

He or she has most likely seen medical controversies come and go, and is usually well equipped to deal with conflicting “expert” opinions, and identify the path most likely to help you!

Upcoming book

Want to read more about BP and its control?

You will not have to wait long for the launch of my new book: “High Blood Pressure: 10 Reasons Your Blood Pressure is Not Under Control.”

Details will follow soon!