A study by the the Institute of Medicine at the behest of the Centers for Disease Control has shown no benefit from sharply decreasing salt intake in preventing strokes and heart attacks even in high risk patients. You may recall that I wrote about the American Society of Nephrology’s recommendation to sharply restrict salt intake in everyone and to restrict intake even more in high risk patients. I pointed out that the ASN’s advice was not based on sound science.
The new report from the Institute of Medicine not only shows that decreasing sodium intake below 2300 mg conveys no benefit, but that it may even be harmful. This report is being greeted with amazement by both the profession and the press. This reaction shows what a mess medicine is in. We should of been able to reach this conclusion 50 years ago on the basis of information available as long ago as the mid 20th century.
Simply put, there is no one sodium intake that is applicable to everyone. If you are in good health and your blood pressure is normal there is no reason to limit sodium intake. If your health is not good and/or your blood pressure is high, you should be under the care of a physician who should put you on a sodium diet appropriate for your medical circumstance.
We’ve known for decades that some people are salt sensitive while others react unfavorably to sodium intakes that the first group finds innocuous. It’s informative to note that the American Heart Association is unimpressed by this report and intends to continue recommending that sodium intake be limited to 2300 mg a day in all subjects; this in the age of Evidence Based Medicine. I look forward with great interest to hearing of the ASN’s reaction to this new finding by the Institute of Medicine.
Why do medical organizations feel the need to make blanket recommendations when silence is the better choice? In many ways they are like serial killers – they can’t help themselves; they have to make recommendations. “Stop me before I recommend again.”
Many years ago, I was the chairman of the Research Council of the Chicago Heart Association. The committee had lunch meeting at the offices of the Heart Association. The lunch was prepared by dietitians who were members of the Association. They honestly believed that salt killed; accordingly, the food was low-sodium and not a salt shaker was to be found. Of course, lunch tasted lousy. I had to bring my own salt shaker to each meeting. This caused a lot of consternation, but as I was a nephrologist rather than a cardiologist my indiscretion was overlooked. Though I left my salt shaker in the middle of the table the cardiologists who were the members of the council were too intimidated by the dietitians to use it. The loss of status overwhelmed the loss of taste. Today I doubt I could get a salt shaker into the building.
Any layman with a core temperature greater than ambient has noticed that medical groups and societies keep changing their minds about important issues. Sometimes the changes are the result of new information, other times they seems to reflect changes in fashion, and at other times confusion reigns. If we have such trouble getting simple things right like how much salt should be consumed, how are we ever going to get the difficult things in order?
For example, how to deliver medical care at a price that will not destroy the world’s economy. The simple saga of salt shows how great the challenge we face when confronted with issues that are really intricate and complex. Unfortunately, a lifetime of observation has convinced me that the highest standard medicine can meet is muddling through. As a teacher and a scientist this conclusion causes me great pain. But I’m afraid it’s correct. Medical students are repeatedly taught that each patient is unique and must be treated as such. So why do we endlessly make recommendations which views them as interchangeable parts?