One of the joys of my commute is the opportunity to listen to stimulating recorded lectures as part of The Teaching Company's Great Courses series. I'm in the middle of part 2 of a course by Steven L. Goldman, Ph.D. on "Great Scientific Ideas That Changed the World."

Lecture 13 on "The birth of Modern Science" discusses the contribution of Francis Bacon, an Elizabethan Renaissance man who developed the modern experimental method. Bacon developed his new method to overcome what he considered the intellectual fallacies of his time which he called "idols" of which there were four: idols of the tribe, idols of the cave, idols of the marketplace and idols of the theater. An idol, in Bacon's terms, was a fascination or fixation without basis in fact and which interferes from acceptance of an accurate understanding of some phenomenon.

Consider how relevant these fallacies are to the current debate on salt and health.

Idols of the tribe are deceptive beliefs inherent in society; they are based on error because they interpret observed relationships through the eyes of (current) orthodox opinion.

Idols of the cave are errors rooted in personal experience and limited by that experience.

Idols of the marketplace are errors rooted in semantics; words conjure up conclusions so the use of improper descriptors induces misunderstanding.

Idols of the theater grow from sophistry, a body of opinion sustained and perpetuated by group acceptance and popularity, but based on false assumptions.

How do Bacon's "idols" relate to the ongoing controversy over salt?

Tribe -- the overwhelming popular majority accept fallacious reasoning that because salt and blood pressure are related and blood pressure and health outcomes are related, that lowering salt will improve health. The evidence shows the contrary.

Cave -- Blood pressure researchers can manipulate subjects' BP by varying salt intake; therefore, they reason that changing BP alone, by any means (and an easy "means" is changing salt intake) will produce better health. There is no evidence to support this conceit.

Marketplace -- It's too bad recently-deceased William Safire didn't address this point. Assertions of "excess dietary sodium" and conclusions that "we eat more salt than we need" are among the several sleights-of-hand employed by salt reduction activists. How do they know better than an individual's neural-hormonal system what is "too much" salt?

Theater -- There are several illustrations, but the easiest to see is the continued preoccupation with endorsement by "expert groups" of the policy recommendation to reduce dietary salt, all the while ignoring the lack of evidence of a health benefit.

We salute Francis Bacon for pioneering a modern scientific method. He would be right at home with his passionate advocacy in today's kerfuffel over dietary salt.

European "food companies guilty of misleading people with health claims" trumpets a headline in the October 2 issue of Medical News Today . The story reports the views of the UK-based activist group Which? quoting the group's chief policy advisor saying of an ongoing review of health claims by the European Food Safety Authority (EFSA):

A huge number of food products claim to have health benefits, but finally we are separating the wheat from the chaff. Incredibly, only a third of health claims looked at by EFSA could be backed up.
Clearly many food companies are exploiting people's interest in improving their health, often over-charging them for alleged health benefits which can't be proved.
On a more positive note, there are foods using proven health claims, so it's vital that industry acts responsibly when making claims, and that the Food Standards Agency ensures the removal of misleading products. Only then can people be confident that the health claims on items they buy are genuine.

Medical News Today reports that EFSA has assessed over 500 claims.
Among the claims supported by Which? and found acceptable by EFSA are claims that reduced sodium foods are healthy. Food companies offering these products are pleased to cooperate to say these foods are healthier for consumers.
Talk about misleading people! EFSA (and Which?) ignore two yawning data gaps that fatally undermine the argument for salt reduction:

1. There is no evidence that there is a net health benefit of reducing dietary salt (pdf 434.26 kB) (in fact, the single controlled trial of the health outcomes (pdf 802.65 kB) of salt reduction found a greater risk among those on low salt diets), and
2. There is no evidence that those who choose low-salt foods (with "healthy" labels) consume lower sodium diets -- the evidence suggests salt appetite is an autonomic physiological response (pdf 517.27 kB) to the body's need for salt.

So, Which?, if food manufacturers are misleading consumers for unsubstantiated claims that their low-salt foods are healthier, you're no better for criticizing them while endorsing the very basis on which their misleading claims are based. As Wikipedia explains, the original idiom about "the pot calling the kettle black " has an alternative, subtler interpretation from a century old poem that extends the critique beyond simple hypocrisy. The poem points out that the actual idiom is "The Pot Bottom Calling The Kettle Bottom Black" drawn from the fact that "the pot is sooty (being placed on a fire), while the kettle is clean and shiny (being placed on coals only), and hence when the pot accuses the kettle of being black, it is the pot’s own sooty reflection that it sees: the pot accuses the kettle of a fault that only the pot has, rather than one that they share." The observation that the root of the problem is that food companies are reflecting back the junk science of groups like EFSA and Which? properly assigns responsibility.
The poem found in "Maxwell's Elementary Grammar" school book, reads:
"Oho!' said the pot to the kettle;
"You are dirty and ugly and black!
Sure no one would think you were metal,
Except when you're given a crack."
"Not so! not so! kettle said to the pot;
"'Tis your own dirty image you see;
For I am so clean -without blemish or blot-
That your blackness is mirrored in me"