Salt – guilty until proven innocent?
It seems to me that every few years there is a new ‘food criminal’. A new study is released demonstrating the affects of a particular food in rats and suddenly the human population has to avoid that food at all costs.
Salt has been on the most hated list for decades. It has been ranked above saturated fat and sugar as a food (a mineral, technically) that should be avoided or consumed in severe moderation.
Recently, a close friend recommended a dietary guideline app to me. Not one to follow diets, I thought this app could be a neat way to track my intake of salt, sugar and fat – something I had never done before. So on day one I entered the food I had eaten. It consisted of fruit, yoghurt and muesli for breakfast, sushi (without soy sauce) for lunch, a handful of almonds and two slices of raisin toast (a slight spread of butter) for afternoon tea and homemade pizza with salad for dinner (no dressing). Apparently my salt consumption was nearly double the recommended daily intake.
How could this be? I had considered my menu for the day to be pretty reasonable. I tried to narrow down the result to determine where I could cut my salt intake for future reference. But alas, I couldn’t figure it out. The only answer was that the guideline was ridiculously low.
Which is why I was somewhat relieved to read this article in the New York Times today. It is written by Gary Taubes, an American Science writer who I met on his travels to Australia last year.
The article outlines the fact that the warnings against salt, which are embedded within dietary guidelines aren’t based on scientific evidence.
Taubes says:
WHY have we been told that salt is so deadly? Well, the advice has always sounded reasonable. It has what nutritionists like to call “biological plausibility.” Eat more salt and your body retains water to maintain a stable concentration of sodium in your blood. This is why eating salty food tends to make us thirsty: we drink more; we retain water. The result can be a temporary increase in blood pressure, which will persist until our kidneys eliminate both salt and water.
The scientific question is whether this temporary phenomenon translates to chronic problems: if we eat too much salt for years, does it raise our blood pressure, cause hypertension, then strokes, and then kill us prematurely? It makes sense, but it’s only a hypothesis. The reason scientists do experiments is to find out if hypotheses are true.
In 1972, when the National Institutes of Health introduced the National High Blood Pressure Education Program to help prevent hypertension, no meaningful experiments had yet been done. The best evidence on the connection between salt and hypertension came from two pieces of research. One was the observation that populations that ate little salt had virtually no hypertension. But those populations didn’t eat a lot of things — sugar, for instance — and any one of those could have been the causal factor. The second was a strain of “salt-sensitive” rats that reliably developed hypertension on a high-salt diet. The catch was that “high salt” to these rats was 60 times more than what the average American consumes.
Still, the program was founded to help prevent hypertension, and prevention programs require preventive measures to recommend. Eating less salt seemed to be the only available option at the time, short of losing weight. Although researchers quietly acknowledged that the data were “inconclusive and contradictory” or “inconsistent and contradictory” — two quotes from the cardiologist Jeremiah Stamler, a leading proponent of the eat-less-salt campaign, in 1967 and 1981 — publicly, the link between salt and blood pressure was upgraded from hypothesis to fact.
The article goes on to detail studies, which have actually indicated that reduced salt intake can cause health issues.
So perhaps salt is not as guilty as first thought. While I won’t be adding salt to my meals anytime soon, I am less worried about the salt included in my already well-balanced diet.
P.S> Interested in this topic? For further reading check out: 8 reasons to never follow a low salt diet
