Thursday, January 29, 2015

Stop Worrying about Salt

When I sit down for dinner tonight, I am going to sprinkle a little salt on the main course.  Also at lunch.

I know, I know.  For many, many years, we have been urged by major medical groups to limit our salt intake.

Now comes a challenge to that rigid nostrum, in a major report from the Institute of Medicine of the National Academy.

The report reviewed the results of many years of studies, worldwide, on "The Consequences of Sodium Reduction in Populations."  (FWIW, I looked up the editors of the report.  Their credentials are impeccable.)

Here's the conclusion:  Too much salt will increase your risk of heart disease.   And so will too little salt.

How Are We Doing?

Let's set the table here.  Americans consume a bit more than 3 grams of daily salt.  Major health agencies have been after us for years to reduce that to 1.5 grams or less per day.

Here are two data points from the recent report:

     --  A 2008 Italian study of Italian heart patients compared two groups, one consuming 1.76 grams and the other 2.76 grams of daily salt with no other dietary changes.  At the end of the study, those eating the lesser level of salt were more than three times as likely to have been readmitted to a hospital and more than twice as likely to have died.

     --  A 2011 study of almost 30,000 people aged 55 and older with high blood pressure.  The report concluded that cardiac risk was higher for those salt consumption was 7 grams or higher and also for those whose consumption was less than three grams.  

The New York Times' very able medical reporter, Gina Kolata, followed up in her story on the report by talking with a doctor with relevant experience.  He told her that as salt consumption declines, bodily levels of triglycerides, insulin resistance and sympathetic nervous system activity increase.  All three are associated with greater cardiac risk.

A Plausible Explanation

In a way, I can see why American nutrition "experts" concluded that we all were eating too much salt. Packaged foods and fast food menu items typically include more salt than meals prepared from scratch in home kitchens.  Salt gives food a nice little kick, and if most of your diet comes from fast-food restaurants, you probably get used to this.

So there is the possibility that at least some of us are getting too much salt.  (Or, possibly, the food authorities were afraid some people out there were having too much fun.)  In fact, prepackaged and fast-food meals also tend to be heavier in saturated fats, which also are tasty and may well be associated with cardiac risk.

As in so many areas, moderation seems to be the best policy.  Our health experts, particularly dietary advisors, have hared down many blind alleys over the years.  (Remember the nutrition pyramid?)  Their credibility would improve if they approached these issues with a little more skepticism and a lot more common sense.


I don't want to beat my own drum too much here, but I have challenged salt-shaming before.  My August 2014 post follows below.

How Much Salt?

"Ideally, the best way to go is completely 'Salt Free.'"

                                                                     From a 2014 Cleveland Clinic post
                                                                     advising on reducing salt intake

For many years now, it has been a received truth that if you suspect you are eating too much salt, then you probably are right.

In 2005, the American Heart Association (AHA) called for Americans to limit their salt intake to less than 2.3 grams daily, or just a teensy bit less than a teaspoon.

In 2010, the Centers for Disease Control took up the cudgel, recommending a maximum of 2.3 grams daily, and even less, 1.5 grams, for children and those over the age of 50.

In 2011, the AHA struck again.  It recommended a maximum of 1.5 milligrams, between half and three-quarters of a teaspoon of salt daily, for all Americans.

According to the AHA, if we all followed this advice (average American salt consumption was just over 3.4 grams at the time), stroke and heart attack deaths would be cut by 20 percent and the country would save $24 billion in health care costs.

I don't eat much salt.  I use very little in cooking, and we never put a salt shaker on the table. Our family eats very little packaged food.  I probably meet the AHA guidelines.

But sometimes I wonder why I bother.

A Study in the UK

In 2011, a British journal reviewed the results of seven studies involving almost 6,500 people who were asked to reduce salt consumption from an average of 8-9 grams per day to 4 grams.

The result:  "Intensive support and encouragement to reduce salt intake did lead to a reduction in salt eaten and a small reduction (emphasis mine) in blood pressure after more than six months."

The researchers' conclusion:  "We believe that we didn't see big benefits in this study because the people in the trials only reduced their salt intake by a moderate amount, so the effect on blood pressure and heart disease did not change."

In other words, having found almost no improvement, the researchers recommended doubling down further on reducing salt consumption. 

In 2011, the National Institute for Health and Clinical Excellence set a country-wide goal of reducing UK salt consumption by half, from 6 grams daily to 3 grams by 2025.

Based on numbers possibly drawn from a hat, the National Institute assured Britons that this dietary change would prevent 40,000 deaths from heart disease.

The Worldwide Study

No doubt you read news reports a couple weeks back about an article in the New England Journal of Medicine.  It concerned a study of 100,000 people worldwide and how much salt they ate.

"In fact," the article said, "People who consumed 3 to 6 grams per day had a lower risk of cardiovascular events than those who had more than 6 grams or less than 3 grams."

So, while US health experts recommend 1.5 grams or less of salt per day, the healthiest people seem to consume between two and four times that amount.

Move along, nothing to see here.

According to the report, only four percent of study participants, in 18 different countries, met recommended American guidelines.  In fact, most people ate from 3 to 6 grams, the amount of salt that correlated with the best results.

I know, I know, perhaps the people who consumed less salt already knew they were at risk of heart disease and had trimmed their consumption.  Possibly that's the real correlation.  Possibly everyone you know who is at risk -- anyone who takes a beta blocker or a statin drug -- also has taken all the salt out of his diet.  Call me a skeptic.  I also find it hard to believe that any of the 17 other countries in the study have as vigilant a bunch of dietary scolds as we do here.

More likely, different people people respond differently to salt.  Maybe genetic differences or the age of the salt eaters has something to do with the inconclusive results.  This has been suggested several times over the last 10 years, and when it has, it has been swatted down and dismissed as unscientific if not outright heresy.

After the latest report showing no correlation between salt consumption and cardiac health, the American Heart Association issued its own advice:

"Looking at the data, we consider it irresponsible not to make recommendations to reduce salt content...."

Well, of course.

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