Salt Study No 'Smoking Gun'

Ever wonder where the fear of eating salt came from?

The big push for salt restriction came after a widely publicized 1984 study called “Intersalt.” This study examined more than 10,000 subjects at 52 locations in 39 countries.

Sounds pretty authoritative, doesn't it. How could a study involving thousands of people in dozens of countries yield a result that, according to my personal investigations several years ago, was wrong? Certainly chips and nachos aren't good for you, but is that because of the salt? If the excessive amounts of salt in junk foods is in fact bad (because it upsets the cell's potassium/sodium balance), does that imply that adding salt to your food is bad?

Read the Wikpedia article to see this one example of how seemingly rigorous scientific research can be misinterpreted.

  

ALL of the statistical validation for the Intersalt study came from 4 indigenous populations that ingested low sodium and alcohol and had no obesity in their populations. There was NO correlation between salt intake and hypertension in the remaining 48 populations; i.e. our population. In fact, the data suggested the opposite after accounting for the outlier data!

  

So how does "science" reach conclusions that are not only wrong, but damaging to society? How can I say "damaging" -- what's the big deal about eating less salt? My point is that it potentially has some impact on the economy (perhaps minor in this case), but a greater damage to the culture. I clearly remember the absolute FEAR that was engendered when the Intersalt study results were communicated. What other "facts" that we didn't know about were "killing us?" Study after study after Intersalt on unrelated topics was more confirmation that we needed scientists to save us. That dramatic impact on our society persists in most people today.

Most scientists are well-intentioned. What about the "scientist culture" can lead to such bad results? We have peer-reviews and public scrutiny to prevent failures of this type. Might it be the pressures of the scientific culture? "Publish or perish?" In today's environment, there are significant economic incentives to become an international authority -- book rights, speaking engagements, etc. I was taught that "intellectual honesty" was crucial to science and in my opinion the countervailing economic pressures have neutralized this important principle.

My science, and "thinking" training, was injected with significant doses of skepticism. Unfortunately, the world is getting so complex that we can't run to ground every new rumor and often can't personally interpret the results of every study that is produced, so we need to discriminatingly evaluate based on our background and common sense.

The area of most significance today for applying this chain of logic are fear-based energy policies on an international scale. See the related blog for more details: http://stevekruba.blogspot.com/2010/11/rational-optimist-how-prosperity.html .