Keep Your Eye on the Evidence to Emotion Ratio

Risk-benefit ratio is a term of art that most anyone in healthcare will know. It answers a very basic question. Does this thing offer more benefits than risks? The thing might be a drug, it might be a device, or it might be an operation. But what about some of the beliefs that drive health and policy decisions? Is the thinking solid? To answer those questions, we suggest you look at the evidence to emotion ratio.

Emotions Run High on Sweeteners

Tamar Haspel puts this question on the table with low-calorie sweeteners. She writes in the Washington Post:

Although added sugar is a top public health concern, diet soda is consistently met with something between distrust and hostility.

Dig into the research, though, and you don’t find a lot of substance. The hostility-to-evidence ratio is way out of whack. What gives?

Lots of people don’t like low-calorie sweeteners, but it has more to do with feelings and suppostions than any real evidence that they cause a problem. In fact, much of the fears attached to low-calorie sweeteners come from correlations and animal data. Meanwhile prospective human studies suggests that these products are generally safe.

As we’ve said before, it’s OK to hate low-calorie sweeteners. Just don’t wrap it in science. The evidence to emotion ratio is low.

Plenty of Other Examples

We go through recurring cycles of fearing bad foods. Right now, carbs represent the boogeyman. And the scariest of them all is sugar, so sugar taxes are sure to help us conquer obesity. Fat used to be scary, but now it’s no problem, especially if it’s part of your “keto” diet. However, objective evidence tells us that neither fats nor carbs are things to loathe. Diet quality matters more than macronutrients.

Smoking rates are at an all time low – both for adults and for youth. But part of the reason is that vaping has become more popular because it’s objectively safer. Moral panic ensues. Only total nicotine abstinence will do, so we have a fevered pitch underway in the U.S. to drive up the fear of vaping. “It’s a ticking time bomb,” says the Truth Initiative.  Elsewhere in the world, public health officials are aiming for fair balance that acknowledges the benefits of e-cigarettes for harm reduction and smoking cessation.

But in the U.S., that’s not happening. San Francisco just banned e-cigarette sales, while permitting continued sales of cigarettes, which are far more dangerous. “Ludicrous,” says a professor of public health. The evidence to emotion ratio is at record lows.

Vaccines offer a good illustration of how much harm can come when emotions carry the day over the evidence. The U.S. is on its way to losing the status of having eradicated a serious disease, measles. Chalk up a win for fear-mongering about vaccines.

Fear and Health

Fear is a lousy way to promote health. Moral panic can do great harm. Rationality goes out the window. Mistakes are made and in the end, health suffers. We must channel our passions into a passion for objectivity. So keep your eye on the evidence to emotion ratio.

Click here for Haspel’s excellent story on the facts and fears about sweeteners.

Passionflower, painting by Piet Mondrian / WikiArt

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June 26, 2019

One Response to “Keep Your Eye on the Evidence to Emotion Ratio”

  1. June 26, 2019 at 10:09 am, Allen Browne said:


    There you go – thinking again!