Modern medicine likes to think of itself as scientific, driven by data. But when new evidence disputes old dogma public health leaders might wish for the old days when dissenters were dealt with harshly.
Heretics Are Burned or Banished:
Once upon a time, heretics were imprisoned and sometimes burned at the stake. The Italian astronomer, philosopher, mathematician, poet and Dominican friar Giordano Bruno was burned alive on February 17th, 1600, in part for suggesting that the sun did not revolve around the earth, the universe was infinite, and that stars were distant suns.
Italian astronomer and physicist Galileo was sentenced to house arrest for life because he too said that the earth was not the center of the universe. He died in 1642, still under arrest by the Vatican for challenging dogma, even though he recanted his scientific observations. To avoid being burned at the stake like Bruno, Galileo was forced to say his findings were “abjured, cursed and detested.”
Pope John Paul II finally admitted 359 years later on October 31, 1992, that Galileo was right. You might be surprised to learn that the investigation by the Vatican took 13 years to complete.
Heretics Who Say Salt is Safe are Spurned:
Fortunately, modern scientists who challenge dogma don’t have to worry about imprisonment or death. But they may be subjected to ridicule or contempt.
Even in the 21st century people may be tempted to shoot the messenger if the message is unwelcome. This became clear recently when the medical journal The Lancet (online May 20, 2016) published research suggesting that a low-salt diet might increase the risk for heart attacks, strokes, heart failure and death.
For decades public health officials have promoted salt restriction as a way of reducing blood pressure and lowering the risk of heart disease. The American Heart Association (AHA) recommends that adults consume no more than 1,500 mg of sodium a day:
“For optimal heart-health, the American Heart Association recommends that Americans should aim to eat no more than 1500 mg of sodium per day, a level associated with a significant reduction in blood pressure.”
The New Data: Salt is Safe at Moderate Levels:
The research published in The Lancet found that the lowest risk of cardiovascular complications and death was actually for people consuming 3,000 to 6,000 mg of sodium daily. That is two to four times higher than the AHA recommendation. It was only when people with high blood pressure went over 6,000 mg of sodium a day that the researchers detected higher rates of cardiovascular complications and death with excessive sodium intake.
Shoot the Messengers Who Say Salt is Safe:
The reaction from the AHA was to disparage the research. The official American Heart Association comment was:
DALLAS, May 20, 2016 – The American Heart Association strongly refutes the findings of a May 20, 2016, article in The Lancet by Mente, et al, that suggest low sodium intake is related to a higher risk of heart disease and death. On the contrary, the link between excessive sodium and high blood pressure – as well as higher risks of heart disease, stroke, heart failure and kidney disease – is indisputable.”
The AHA declared, “the public should not be confused by the flawed study.”
Francesco Cappuccio, MD, head of the World Health Organization’s Collaborating Centre for Nutrition, was also dismayed:
“It is with disbelief that we should read such bad science published in The Lancet…The evidence supporting global actions for a moderate reduction in salt consumption to prevent cardiovascular disease is strong and such studies should not overturn the concerted public health action to reduce salt intake globally.”
Should you actually wish to read the details of the new study in The Lancet for yourself and make up your own mind about whether salt is safe at moderate levels, here is a link. You will find that the “sweet spot” for sodium appears to be much higher than the American Heart Association, the CDC and the FDA recommend. You will also find out why a very low-salt diet might be hazardous to your health. And by the way, 1,500 mg of sodium is a very low salt diet. You can hear the lead author interviewed of The Lancet study on The People’s Pharmacy radio show this coming Saturday. He will dispute that his study was flawed and tell you why. Tune in or download the podcast after the broadcast so you can judge for yourself.
Keeping up with the Science on Salt and Saturated Fat:
Apparently our public health officials have not been keeping up with research. The Institute of Medicine, one of the most prestigious medical organizations in the world, noted that there was inadequate evidence to support the 1500 mg per day sodium recommendation (JAMA Internal Medicine, Jan. 2014). In addition, a meta-analysis of 25 earlier studies found a higher risk of premature death associated with sodium restriction (American Journal of Hypertension, Sept., 2014).
The Saturated Fat Heretics:
The dismissive reaction to the new salt study is reminiscent of responses to studies showing that saturated fat consumption is not as dangerous as it has been portrayed. The Minnesota Coronary Experiment was a large trial conducted in the late 1960s and early 1970s in which some people were randomly assigned to follow a diet in which corn oil replaced butter and other saturated fat.
Corn oil lowered cholesterol, but it did not reduce death from heart attacks. The data were not published until recently, and experts were shocked to see that people getting the low sat-fat diet were at higher rather than lower risk of coronary events. The reaction: don’t trust the study.
If you would like to read details of the new study and get The People’s Pharmacy take on the data, here is a link.
Sometimes the Heretics are Right!
Nutrition experts and cardiologists are finding it hard to imagine that the diet-heart hypothesis might be flawed. This concept has driven dietary recommendations for decades, based on the idea that lowering cholesterol will prevent heart disease. Apparently, the story is not quite so straightforward.
We would hope that when a scientific study uncovers an unexpected result, the response would be curiosity rather than condemnation. After all, sometimes the heretics are right. Let’s hope it doesn’t take hundreds of years to get the greater popes of public health to accept the new data.
