Friday, April 19, 2013

Precautionary Principle

The precautionary principle is the idea that new things should be forbidden until they are proven to be safe. It is opposed to our traditions of freedom, which say that people are innocent until proven guilty and should be allowed to do what they want unless the state can prove that they are harming others. It is also opposed to cost-benefit analysis, which says that things should only be forbidden if the likely harm is greater than the likely benefits.

The precautionary principle is closely tied to the human instincts of repugnance and disgust. People are far more likely to apply it to things that seem 'wrong' or 'bad'. Once something flips a mental switch, people enter a new mode of thinking where tolerance disappears and they become extremely conservative and suspicious. Rather than thinking about the new thing in a balanced way, they decide that the new thing is bad and demand impossible proof that it is harmless.

People are especially likely to apply the precautionary principle to food. There are good evolutionary reasons for this. The natural world is full of toxic substances that will kill or sicken someone who eats them. People who ate everything without question were less likely to pass on their genes than people who waited to make sure that the thing was safe before eating it.

Like many instinctive behaviors, the precautionary principle leads to bad results in the modern world. The benefits of modern civilization that have allowed us to escape from the nasty, brutish, and short lives of our ancestors come from scientific innovation. The precautionary principle makes this innovation much harder. Most of the good things of civilization have some kind of associated harm. Sometimes the harm is small, and sometimes the harm is significant, but it is usually much smaller than the benefits. If our ancestors had applied the precautionary principle to every innovation, we would still be in the dark ages.

Sometimes the benefits are hard to see, and the harms are obvious. For example, agricultural chemicals make fresh vegetables cheaper, which allows more people to eat vegetables more often, which improves the diet and delivers small health benefits to large numbers of people. However, those same chemicals cause some people to get cancer. The health benefits from the cheaper vegetables are several orders of magnitude larger than the harm done by the cancer, but the cancer is much more visible, so people pay more attention to it.

The tools of science can give us good estimates of how much harm something is likely to cause. Because all good science deals with probabilities and not certainties, it is impossible to prove that something will have zero harm. Even if we predict some harm, we may also predict that the benefits are likely to be much larger than the harm. In both of these situations, a scientific cost-benefit analysis will say to do something, while the precautionary principle will say not to.

However, the precautionary principle makes better stories and narratives than science, because it is closer to human instincts. It feels more moral for people to apply the precautionary principle than to crunch numbers. Often, these feelings are what drive policy. People trust their instincts instead of the scientific method, and stop or delay new technologies. The end result of this is that we are stuck with old and inefficient ways of doing things, wasting valuable resources that could be used to improve our lives and our society.

Thursday, April 11, 2013

Naturalistic Fallacy

The naturalistic fallacy, or the appeal to nature, is the belief that natural things must be good and unnatural things must be bad. This belief causes a lot of problems in the food market.

A big problem comes from the fact that the word 'natural' has no real meaning or definition. It is just a vague fuzzy concept that is different for everybody. This means that advertisers and marketers can use the word to mean almost anything they want. A recent court decision threw out a case where a company was being sued for using high fructose corn syrup in a product and calling it 'all-natural'. I personally would consider corn syrup to be a synthetic substance, because it comes from a factory, but the court ruled otherwise.

This is a good object lesson. There are a lot of words like 'natural', 'fresh', 'fair', and 'healthy' that sound good but are hard to define in terms of numbers or logic or things that can be measured in a lab. When you see someone using those words, you should assume that they are trying to manipulate you.

In fact, a good rule to follow is to never trust anything on a food package outside the nutrition facts panel. There are a few rules about what can and cannot be said, but they are fairly easy to slither around. On the rare occasions when I buy packaged foods, I only look at the ingredients and nutrients in the nutrition facts panel and consider everything else on the package to be meaningless noise.

But even if the word 'natural' had a clear legal definition that was consistently enforced, it would not be a good guide to healthy eating. Lots of natural things, like slabs of organic red meat loaded with saturated fats, are not healthy and should only be eaten in moderation if at all. Lots of unnatural things, like iodine in salt, are public health miracles that save billions of people from nasty diseases.

It is true that chemical factories produce a lot of substances not found in nature. But it is not true that our body is helpless to deal with these things. In nature, plants are in a constant state of chemical warfare with the things that want to eat them. Humans have an amazing ability to detoxify these poisons. We can eat and enjoy things like chocolate that are full of chemicals that can kill other mammals like cats and dogs. The detox systems of our bodies can usually deal with nasty artificial chemicals the same way they deal with nasty natural chemicals.

For example, we now know that even the detox systems of a fetus can render harmless the amounts of BPA found in our food. If you do not know what BPA is, then you do not need to. If you have read or heard that it is harmful, than you can stop worrying.

Our instincts want to classify everything as bad or good, and then to completely avoid bad things while seeking more of the good things. The naturalistic fallacy is a subset of that problem. The world does not work like that. The dose makes the poison. Essential vitamins can kill you in large doses. Nasty chemicals are harmless at small doses. As in many things, moderation is the key.

Now, however, I should point out that many of the fundamental rules for a healthy diet are similar to the naturalistic fallacy. You should limit your consumption of packaged food and eat lots of raw agricultural commodities. You should avoid eating things like refined sugar in quantities larger than the human body evolved to handle. You should remember that many important nutrients like calcium will only help you if you eat them in food, and that dietary supplements with those same nutrients are worthless or even harmful because the nutrient is in an unnatural form that the body cannot absorb properly.

As usual, the conclusion is to avoid simplistic thinking about the world, and consider the science and evidence. Understanding the sciences of biology and chemistry and psychology will allow you to make good decisions about things you have not seen before, while relying on simple intuitions or trying to memorize a list of good and bad things will not lead to good results.