Filed under: Depression, Gene Roddenberry, Health, Science, Science Fiction, Society, Star Trek, Survival
Back in the 1960s, salt was just salt. Known to be necessary for healthy life in most mammals, including humans, people didn’t give it a lot of thought beyond that. Oh, sure, sometimes people would worry about a salt deficiency – I remember taking salt tablets regularly the summer I worked as a hot tar roofer – but otherwise, it was no big deal. In fact, one of the early episodes of Star Trek had the M-113 Creature, as ‘salt vampire’ which killed by sucking the salt out of humans.
Then came the 1980s. And the start of the great salt scare.
Salt was tied to hypertension. Salt was found to be overused in all kinds of prepared foods (since it augments flavor and increases food density – what the industry calls “mouthfeel” by saturating food with more water). We were told that salt kills – and that you had damned well better cut back on the amount of salt you ate. Anyone with high blood pressure or heart disease was told to go on a low- or no-salt diet, using salt substitutes or just going without.
What wasn’t really discussed by the public health officials who got this bandwagon started was that only some people are salt-sensitive, i.e.: react to excess salt in their diet. I’m not going to dig back through all the research papers now, but I remember that it was estimated that for the US this was about 30% of the population. For those people, salt could indeed pose a problem. But most people didn’t have this kind of reaction – their system would just flush excess salt out through normal kidney function. Here’s a passage from the Wikipedia article on salt which addresses this:
Sodium is one of the primary electrolytes in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are available in unrefined salt, as are other vital minerals needed for optimal bodily function. Too much or too little salt in the diet can lead to muscle cramps, dizziness, or even an electrolyte disturbance, which can cause severe, even fatal, neurological problems. Drinking too much water, with insufficient salt intake, puts a person at risk of water intoxication (hyponatremia). Salt is even sometimes used as a health aid, such as in treatment of dysautonomia.
The risk for disease due to insufficient or excessive salt intake varies because of biochemical individuality. Some have asserted that while the risks of consuming too much salt are real, the risks have been exaggerated for most people, or that the studies done on the consumption of salt can be interpreted in many different ways. 
Now, from a public health perspective, it makes sense to try and limit the average intake of salt. As noted, many prepared foods have a *lot* of salt in them. If you can stop 30%, or one third, or one quarter, of your population from developing high blood pressure without causing problems for the rest of the population, then why not? And I think that this is probably the reason and rationale behind the extensive public health campaigns to get people to cut back on salt intake, though I bet it would be difficult to get most public health officials to admit that this was the case.
But . . . what if a decrease in salt presented problems for that other portion of the population that is not salt-sensitive?
University of Iowa researchers writing in Psychology and Behavior say salt may act as a natural antidepressant.
Tests on rats found those with a salt deficiency shied away from activities they normally enjoyed – a sign of depression.
* * *
The tests carried out by US researchers found that when rats were deficient in salt, they shy away from activities they normally enjoy, like drinking a sugary substance or pressing a bar that stimulates a pleasant sensation in their brains.
Psychologist Kim Johnson, who led the research, said: “Things that normally would be pleasurable for rats didn’t elicit the same degree of relish, which leads us to believe that a salt deficit and the craving associated with it can induce one of the key symptoms associated with depression.”
Now what? Risk hypertension, or fight depression? What is the biggest public health concern?
As I’ve noted before, I *do* have problems with high blood pressure (though thanks to changes in lifestyle – specifically, getting regular sleep and exercise – combined with drug therapy, it is now coming down to close to the “normal” range). But I don’t seem to be salt-sensitive – drastically cutting my salt intake makes no difference in my blood pressure. My doctor doesn’t worry about my salt intake, saying that other factors are likely much more important in dealing with my hypertension.
But what about depression? Or just worrying about whether you’re going to die from too much salt?
I think Gene Roddenberry was right: sucking all the salt out of us is like sucking the life out of us. Or at least the joy of living.
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