My phone has been ringing off the hook ever since the recent media release about salt from the Institute of Medicine (IOM for short) came out. “Did you hear, the New York Times is reporting that you don’t have watch your salt anymore” says one my medical colleagues. Most of the callers have referenced the same New York Times piece. As I look at the rest of the major media coverage, some outlets have gone even further, featuring pictures of French fries, soups, donuts and salt shakers in action, all suggesting it is now okay to eat as much salt as you want.
I am sure the IOM must be shocked at the way the media has played their information. After reading their report, I know I am.
The IOM has previously recommended 2,300 mg salt limit. Last fall, the American Heart Association issued a lower limit of 1,500 mg. That is the rub between the two good organizations. The discussion is not about whether to reduce salt intake but to what level. Unfortunately many of the headlines and almost all of the spin (especially in the Times) would have you believe that you don’t need to restrict your salt at all.
The kind of media coverage may be one of the main reasons why we are making no headway in overcoming the massive impact of our habitual salt intake, which is public enemy number one. To put this in perspective, everybody is driving at a dangerous speed of 200 mph through city streets and we are arguing about whether the speed limit should be 25 or 30 miles an hour. I am reminded of the words of Professor Stephen MacMahon: “It is the blood pressure, stupid.” His words were intended to emphasize the urgent need to focus our energies on actually lowering blood pressure to reduce the risk of strokes instead of arguing about which drug works better to lower blood pressure.
Let’s us look at some of the concerns regarding salt consumption. Nine out ten people who need follow salt restriction don’t. Despite many multinational organizations working to create salt awareness, the levels in processed food and restaurant foods has not budged. During that same time period, the availability of healthy food choices for children in fast food franchises has gone up to a mere 3 percent from an abysmally low 1 percent. This dismal state of salt awareness has led to over a billion people worldwide suffering from high blood pressure. Millions upon millions are popping more and more pills and still suffering from heart attacks, heart failures, strokes, broken bones and more, all caused by or aggravated by salt intake. And new evidence of the expanding devastation caused by our salt habit has received lukewarm media attention so far. It’s as if the salt industry has hired the entire media to be its lobbyists.
Getting back to the actual IOM press release, which you can read for yourself at the link provided below.
The very first words in bold print in the press release:
Studies support population-based efforts to lower excessive dietary sodium intakes.
As you go down the report, the IOM committee has issued its conclusions beginning with the following bullet point:
Evidence supports a positive relationship between higher levels of sodium intake and risk of heart disease, which is consistent with previous research based on sodium’s effects on blood pressure.
I cannot for a minute understand how one could get to “we don’t need watch how much salt we eat“ from these crystal clear statements.
The next three bullet points in the conclusion deal with poor quality, inconsistency, and insufficient quantity of evidence to determine whether lowering salt intake to 1,500 mg is helpful or not.
You may recall an ad campaign by one of the discount electronic retailers. It went something like this.
Point number one, nobody can beat our prices.
Point number two; see point number one
Point number three; see point number one.
The idea was to focus on the most important message. In the IOM press release, the most important message—that salt is detrimental to our health—seems to have been completely ignored.
Yes, the IOM’s media release did discuss inadequate sodium levels, noting problems that occurred in end-stage heart failure patients already on multiple medications. No study, however, has indicated that too low of a salt intake is bad for healthy people. With due respect too many eminent scientists on the IOM panel, I have to side with the American Heart Association (AHA) on this issue.
Similar discussions have occurred regarding the issue of obesity. The people with lowest body mass index (BMI) fared poorly on when it came to health indicators, leading spin docs to claim that moderate obesity is where you want to be. In reality these people in the lowest BMI brackest were actually dealing with end-stage cancers, heart failure and other chronic GI diseases. Obviously they were going to not fare well. That does not mean one should be moderately obese to gain the best health odds.
In addition, the blood pressure response to salt intake is linearly proportional to salt intake, meaning that the higher salt intake, the higher the blood pressure goes. You don’t get a pass for the first 1,500mg or 2,000 mg. Dr. Lewis K. Dahl, who researched high blood pressure for many decades at Brookhaven Laboratories did not say that the line for blood pressure is flat for a certain amount of salt intake and then begins to rise. Instead, he called salt the “deadliest spice” and specified that adding salt to our food is “not physiologic.”
In short, this is not like saying that you’re safe and won’t get a speeding ticket unless you go more than five to ten miles over the speed limit. When salt is involved, you can get nailed at any speed at any time. That’s why I don’t believe that there is any level of salt intake that is actually safe. No good can come from adding even the smallest amount of salt. Therefore I draw an even stricter line than the AHA. I don’t see any basis to allow even the smallest amount of salt. Besides, I don’t see how an average Joe on the street can tell the difference between 2,300 and 1,500 mg of salt. To be realistic and pragmatic, you have to shoot for the lowest level of salt intake you can achieve.
To make my point further, I draw your attention to the report in Lancet referenced below. Data gathered in one million adults showed that for each increase in systolic pressure of 20 mmhg there was greater than two-fold increase in cardiovascular mortality. It’s worth noting that the starting point for this discussion was 115 mmhg. The same held true for a 10 mmhg increase in diastolic pressure with a starting point of 75mmhg. Remember, this was by no means a small study.
This finding means that by the time we recognize high blood pressure at 140/90, we already are living with an almost three-fold increase in cardiovascular mortality. Therefore even prehypertension (above normal but below 140/90), as you can see in the graph below, is already hurting millions. Since we don’t get a pass at any level of BP higher than normal, the AHA’s position to shoot for the prevention of hypertension is right.
The IOM concluded its report by stating that further study was needed to shed more light on 1,500 vs 2,300 mg sodium diet. Come on now! Give me a break. I cannot begin to tell you how many times the limitation of this statement has been discussed. Studies in animals have shown that it takes about a third or more of the life time of salt intake to manifest hypertension. In human beings, adding salt from the very first solid meal in infancy results in high blood pressure generally recognized in one’s 50s and 60s. Before that, we’ve gone through a period of a couple of decades during which our prehypertension is totally ignored, eliminating any chance for prevention. That’s really too bad, because once high blood pressure has set in, related organ damage will begin to show up 10 to 20 years down the line.
The limitation of the human studies lies in the difficulty of studying the impact of different levels of salt restriction for so many decades. Those kinds of studies needed to settle the current dispute cannot be realistically designed. Can you imagine placing sizable portions of the population at different levels of salt and studying them for 50 years? That is impossible. So, we have to use rest of the evidence.
We know that half of all those with high blood pressure either are not aware of their condition or don’t have it under control. That’s about half a billion people in this world. Debating how low salt restriction should be only adds to the confusion, which the salt industry loves. All interested parties should instead focus their energies on educating citizens about the dangers of salt, especially since the impact of salt consumption on non-cardiac diseases could be even more staggering than what it does to the heart. We will talk about that next time.
In the meantime, this misuse of “the expensive piece of journalistic real estate” to paraphrase Dr. Michael F. Jacobson of the Center for Science in the Public Interest (CSPI) by some the most talented writers in the industry hurts millions of people. On behalf of more than a billion people who suffer consequences of the salt habit, I am urging the rest of the media who have not weighed in yet to engage and set the record straight.
IOM press release:
American Heart Association response:
Lancet. 2002 Dec 14; 360(9349):1903-13.
Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies.
Lewington S, Clarke R, Qizilbash N, Peto R, Collins R; Prospective Studies Collaboration.