When I read that something is good or bad for you, the first question I ask myself is “Who would pay for that study?”

Is coffee good or bad for you? Is kale a better food for you than sprouts? Does Acai really prevent cancer? Is red meat really worse for you than pork?

Let’s take coffee as an example. Who would pay for coffee studies that would show coffee is good for you:

Essentially, the groups and brands that stand to profit off selling more coffee would want to produce studies that show coffee will save your life.

Now let’s think about who would pay for a study that finds coffee is bad for you. Hmm…religions that denounce caffeine? Or maybe an interested medical student doing a medical student project with a few hundred people? 

The point is, good research costs a lot of money and takes a lot of time. You’ve got to produce research that provides results that justify the expense of doing that research. And when it comes to singling out a substance like coffee and studying this substance and its effects over decades on human beings, things get super complicated super quickly. Humans are ridiculously complex organisms. We probably put thousands of different substances in our bodies every day. Compound this with the fact that there is nobody in this world with your same genetic makeup. Compound this with the fact that there is nobody in the world that eats, drinks, sleeps, moves, works, socializes, and plays exactly like you. 

Because we are so complex and impossible to control, we have to guesstimate a substance’s effects on us. And, for the vast majority of substances, the only entities willing to spend the money on guesstimating are those entities that stand to make a profit. Their position is best stated by David Freedman in The Atlantic:

Simply put, if you’re attracted to ideas that have a good chance of being wrong, and if you’re motivated to prove them right, and if you have a little wiggle room in how you assemble the evidence, you’ll probably succeed in proving wrong theories right…

Salt is undergoing the same treatment right now. Here’s the latest bit from The Times: 

While, back then, the evidence merely failed to demonstrate that salt was harmful, the evidence from studies published over the past two years actually suggests that restricting how much salt we eat can increase our likelihood of dying prematurely. Put simply, the possibility has been raised that if we were to eat as little salt as the U.S.D.A. and the C.D.C. recommend, we’d be harming rather than helping ourselves.

Who would pay for studying salt? And that’s the first question you must always ask yourself when you read these kinds of claims.

If you want my opinion, I don’t pay much attention to any of this nonsense. I believe that humans are so ridiculously difficult to study and control. We’ll basically only know with scientific proof about substances that are immediately harmful or even deadly. For all other substances, we’re playing around with differences of +/- 5%, and that my friends is ripe for fudging and totally irrelevant to me as an individual.