On this episode of Life, the Universe & Everything Else, Gem talks about Google’s search autocomplete feature, then Lauren, Ashlyn, Laura, and Gem answer twenty of the most popular questions suggested by Google.
Life, the Universe & Everything Else is a podcast that delves into issues of science, critical thinking, and secular humanism.
Correction: When answering the question, “Where is your liver?” Ashlyn misspoke: the liver is of course located below the diaphragm, not above it. Whoops!
Salt is bad, right? Refined foods are bad, right? So it must follow that the refined, ubiquitous condiment table salt must pose a health risk to humans greater than mercury, werewolves, and bears combined. At least so says this article. It’s another iteration of a health claim that has been around for several years: table salt=bad, sea salt/Himalayan salt/exotic, expensive salt of your choice=good. As always, extraordinary claims require extraordinary evidence, so let’s see how the claims for salt stack up against the evidence.
First, the claim that table salt is not real salt. For most of us, salt refers to sodium chloride, an edible crystalline product that provides most of our sodium intake. Table salt contains 97% or more sodium chloride; I find it hard to see how table salt does not then qualify as “real” salt (other salts contain 90-97% sodium chloride). I will note, now, that the term salt has very broad usage in chemistry; many things can be considered a salt. But I digress. True, the salt in our shakers does not emerge from the earth in such pure white and uniform crystals, but that does not make it less salt. This claim is an appeal to the naturalistic fallacy, of which I am no fan. Avoiding refined foods is a good rule of thumb when planning your diet, but salt (whatever type you like) is not a food. It is a mineral compound, an ingredient. It affects our health and nutrition but is not, nor was it ever, a significant source of nutrition. Hence, it is not fair to liken salt that has been refined into table salt to corn kernels that have been refined into cheese puffs.
Next, the article claims that the negative health effects of salt intake, most notably high blood pressure (though there is the evidence is unclear regarding the link between salt/sodium intake and cardiac event risk) are due to the high sodium content of table salt without adequate magnesium to balance it (the magnesium having been stripped away during refining). Inadequate magnesium intake does appear to play a role in high blood pressure, among other health conditions. Adult humans require 320-400 mg magnesium daily; typical intake from the western diet appears to be declining. Table salt is almost completely devoid of magnesium, while sea salt and Himalayan salt do contain some. These salts also contain some amount of various other minerals, the exact compositions varying based on where the salt originated. However, it is the dose that makes the cure or the poison. Per teaspoon, sea salt contains approximately 20 mg magnesium and Himalayan salt provides approximately 0.00092 mg magnesium. Even if you did consume 1 teaspoon of sea salt a day, you would only get 5% of the RDA; that one teaspoon also provides almost the entire day’s allotment of sodium. Compare that to 1 oz dry roasted almonds that provide 20% of the RDA with minimal added sodium. Increasing magnesium in the diet is probably a good idea for most of us; the type of salt we choose will have a negligible effect on our overall intake. The same goes for all the other trace minerals found in unrefined salts.
Third, the author starts discussing the dangers of inadequate sodium intake. It’s not clear what this has to do with the type of salt we choose; if we are concerned about not getting enough, then it seems that table salt would be the most reasonable choice as it typically has the most sodium (as noted above). But of course, outside of severely sodium-restricted diets, water intoxication, and a few rarely disorders, low sodium intake is of no concern: we typically consume about 3400 mg sodium daily while our needs are only 1500 mg. The author correctly points out that sodium is vital for proper nerve conduction and hydration, but what is not made clear is that, because of the importance of this nutrient, sodium regulation is a tightly controlled process . Our sodium levels are largely independent of intake; you could eat 10,000 mg sodium a day without raising your blood sodium levels.
The article goes on to fear-monger about the bleaching process and additives in table salt like anti-caking agents which contain aluminum or ferrocyanide (both of which a regulated and found to be safe for human consumption). The important point here is that these additives are in minute amounts and are unlikely to cause harm. We have far better things to worry about than this.
There are lots of salts on the market, but the biggest differences are the look, taste, and cost. Choose the one you like best, use the least amount you need for flavour, and don’t for a minute think that you are getting a hefty dose of any minerals other than sodium and chloride.