What’s the first thing that comes to mind when you think about advice for lowering blood pressure?
It’s very likely to be the constant refrain to restrict salt intake. It’s hardly surprising; look at any health or medical website and the first tip you’re likely to see for reducing blood pressure is to “cut back on salt”. We’ve been lectured about this for so long, decades in fact, that salt (sodium) has become inextricably linked to hypertension (high blood pressure).
But is it true? Or could it be that like many things that we’ve heard over and over, it’s just a big fat myth? In other words…
Will cutting your salt intake really help in lowering blood pressure?
That’s a great question that many people (when they stop and Blood balance formula and Blood balance advanced formula think about it) would like to have answered: I mean, let’s say you follow a pretty good diet… do you need to worry about salt?
You see, this whole salt thing has been haunting us since back in the 1970’s, when Lewis Dahl did a study showing that higher salt intake raised the blood pressure of rats in a lab. Of course bad news gets attention and many people took the conclusions of that study at face value and ran with them. But there were serious flaws in the study that were widely overlooked in the zeal to identify a culprit for hypertension.
First of all, the rats were fed an amount of salt equivalent to a human consumption of five hundred GRAMS daily. By contrast, the average human salt intake is around 2500 mg (2.5 grams) per day.
And this wasn’t the only problem with Dahl’s study. Let’s just say it was basically flimsy. But despite this…
U.S. Surgeon General links salt/sodium to hypertension…
In 1979 the U.S. Surgeon General’s annual report included a blanket statement about salt and it’s link to hypertension, but even this report was a bit iffy on details. Here’s what it said:
High dietary salt intake may produce high blood pressure, particularly in susceptible people… Unequivocally, studies in genetically predisposed animals show a cause-effect relationship between high salt intake and elevated blood pressure. Studies in man also suggest such a relationship and show, too, that when hypertension is present controlling salt intake can help combat it.
Not the sturdiest of arguments, and when you understand that the “studies in genetically predisposed animals” was based largely on Dahl’s study, it sort of makes you question the word “unequivocally”, does it not?
The shaky edifice that salt prohibition was built on continued to rise, with health professionals always “erring on the side of caution” and the general public eager to accept their edicts without reading the fine print behind them. And so it was that we came to assume that high salt/sodium intake was a major cause of hypertension.
Cut back on salt for lower blood pressure: the evidence mounts (or does it?)…
The next battle in the war against salt was set to kick off. In 1988 researchers set out to prove Dahl’s “salt hypothesis” with the biggest study ever on the correlation between salt consumption and hypertension. This study observed 52 population groups spread over 32 countries worldwide and took four years to complete.
But once again, the evidence that came back was less than “unequivocal”. It did conclude that part of the Dahl salt hypothesis was correct, that “there is a steady positive correlation between salt (sodium) intake and mean systolic blood pressure (MSBP). Specifically, that MSBP drops 1-6 mm HG for 100 mmol reduction in daily sodium intake”.*
*British Medical Journal INTERSALT: an international study of electrolyte excretion and blood pressure: results for 24 hour urinary sodium and potassium excretion, INTERSALT Cooperative Research Group, BMJ, 1988)
But, again, there’s a problem with these findings: Of the fifty-two social groups studied, four were primitive societies whose salt consumption and blood pressure were both extremely low. WITH these four groups included in the data there was a positive relationship between salt and blood pressure. But WITHOUT these four groups, data for the other forty-eight groups showed no relationship whatsoever.
There’s more: the conclusions fail to take into account the fact that the four primitive societies experienced less stress, consumed a low fat/high fiber diet, had far less obesity and consumed much fewer processed foods. All or any of these factors could very well have influenced the group’s blood pressure and thus the study’s findings.