American and European experts on cardiovascular disease disagree about salt. An article in the European Heart Journal recently pointed out that there is little or no evidence supporting the extremely stringent guidelines put forth by the American Heart Association. The main source of sodium in our diets is salt, sodium chloride.
How Much Sodium Is Too Much?
The authors acknowledge that sodium intake above 5 grams a day is clearly linked to more cardiovascular disease and death in populations. That’s why they “support interventions to reduce sodium intake in populations who consume …> 5g/day.” This amount of sodium is roughly three times higher than the AHA guidelines, which urge people to get their sodium intake down to 1.5 g/day or lower.
Such disagreements between American and European experts, and even among the Americans, are not new. Seven years ago we received this question from a reader:
Restricting Salt to Control Blood Pressure:
Q. My blood pressure is slightly elevated. I take a water pill to control it, and my doctor suggested that I restrict salt.
My adult-ed science teacher claims that only half the adult population is sensitive to salt so that it makes their blood pressure rise.
I went on an extremely salt-restricted diet for a month and had no change in my blood pressure. My doctor now says I can eat normally.
Please tell people that they should run this experiment themselves before spending the rest of their lives hunting for low-salt foods. Life is complicated on a restricted diet, and it would be a shame to do this if it isn’t needed.
A. The link between salt (sodium chloride) and high blood pressure has been controversial for decades. Studies suggest that cutting back on salt can lower blood pressure modestly. A carefully run, long-term trial found that substantial sodium reduction only lowers blood pressure two or thee points (Journal of Human Hypertension, Jan. 2005).
People Are Different with Respect to Salt Sensitivity:
Some people are especially salt sensitive and benefit from a sodium-restricted diet. Others, like you, don’t see any improvement.
A comprehensive study in the British Medical Journal (April 28, 2007) found that sodium restriction led to a 25 percent decline in heart attacks and strokes. Even though cutting back on salt may not make a big difference for everyone, it clearly can help some people delay death from cardiovascular disease.
More Controversy Over Salt:
Japanese experts have also found a link between higher sodium intake and an increased risk of hypertension (Takase et al, Journal of the American Heart Association, July 29, 2015; Murai et al, Journal of Hypertension, June, 2015, Supplement 1). A meta-analysis of 34 randomized trials found that modest salt reduction, to around 3 g/day, for at least a month lowered blood pressure significantly (He et al, BMJ, April 3, 2013).
Just to underscore that not everyone benefits from cutting salt, however, is a study of nearly 7,000 American adults. It found no connection between sodium or potassium intake and elevated blood pressure (Sharma et al, Journal of Clinical Hypertension, April 11, 2014).
What Are the Risks of Cutting Out Salt?
We have written previously about disagreements between experts with respect to sodium. We think people should be warned that following strict AHA guidelines and eliminating salt from the diet to achieve a very low sodium intake may have risks.
Using a salt substitute can sometimes be a good choice for people trying to reduce their sodium intake. But this too may be dangerous, especially if people are taking blood pressure medicines that push the body to hang onto potassium. Excess potassium can become deadly.