Why salt?

Those of you who were paying attention yesterday will already be aware that I have been doing a bit of salt mining. This is fairly easy to get away with when, like me, you’re new to the database and thus ‘have to get to grips with it’. So I have been plugging in various ‘preferred’ search terms and generally navigating my way around. The results are throwing up some interesting gems, sorry, ‘crystals’, since it’s salt we’re talking about this week.

If our salt (specifically sodium) intake is worryingly high enough to have increased problems with hypertension and its related disorders, why do we want to eat so much of it? And is this behaviour innate or learned?

The issue of our appetite for salt as a species was hot enough, yet researched enough in the late 1960’s to merit a full review, published in Nutrition Abstracts and Reviews. Dr. Derek Denton of the University of Melbourne, Australia was kind enough to convert one of his lectures, delivered at the 24^th International Congress of Physiological Sciences in Washington, into a full paper. Presumably he bumped into one of my predecessors there (you can still do this, by the way).

Denton pointed out that during man’s evolution, the tropical environment put quite a lot of pressure on the limited amount of salt available in the diet through a diet based largely on roots, shoots and fruits. He based this on work from colleagues in Australia who had studies the diets of remote communities in the highlands of tropical New Guinea. Coupling these low sodium, high potassium diets with the stresses of temperature control, sweating and other fluid losses through infection and fever, Denton clearly believed that there must be some degree of biochemical programming involved. Furthermore, while the ‘mechanism invoking salt appetite is not understood’, he maintained that some ‘complex neurochemical process’ underlies salt appetite.

If you have a subscription to CAB Direct, you can find the full review and more interesting stuff on our innate and leaned preferences for salt by searching the archive. Just check the ‘All Archive Database from 1900-1983’ (yes, it goes back that far!) option, then search for ‘salt preference’. Happy browsing!

Comments

[foods that lower blood pressure]

"Denton pointed out that during man’s evolution, the tropical environment put quite a lot of pressure on the limited amount of salt available in the diet through a diet based largely on roots"...Perhaps this resulted in the phrase "Worth his salt?"

Junk food industry loves this fact, I have to imagine. I can't fathom how much our natural salt craving means, in dollars, to snack food makers.

[Sarah Mellor]

That's an interesting point and may well explain why we crave salt. (I guess biochemistry determines our anility to absorb it so well to maintain cells' electrolyte balance). Is this the reference you quote?

'Dietary sodium chloride (salt), other dietary components and blood pressure: paradigm expansion, not paradigm shift.'
Stamler, J. Appel, L. Cooper, R. Denton, D. Dyer, A. R. Elliott, P. Greenland, P. Kesteloot, H. Kumanyika, S. Liu Kiang Marmot, M. Horn, L. van Whelton, P.

Acta Cardiologica, 2000, Vol. 55, No. 2, pp. 73-78, 34 ref.

I gleaned this from a search of CAB Abstracts, but if you have another source, please let me know!

http://217.154.120.6/NutritionAndFoodSciences/show-article-details.nsp?lastquery=%28denton%29%

I would agree that an innate taste for salt is an easy target for the food processing industry to use, given that it is a relatively cheap food preserving agent. However, I would express concern that while advice to avoid salt by reading the labels on packaging (as you so sensibly recommend on your website), it can easily be taken to an extreme and can make some groups of people vulnerable to other disorders, rather than simply protect them from hypertension. I for one would be interested to see if the medics report any improvements as a results of efforts on the part of governments' 'salt reduction' campaigns, including targets set for the food industry.