Updated: Aug 3
The Oxford dictionary defines a fallacy as, “a mistaken belief, especially one based on unsound argument.” The naturalistic fallacy is a logical fallacy which argues if something is “natural,” it must be good, and if it is “unnatural,” it must be bad. This fallacy can be applied to a variety of domains but for our purposes we will only look at how it applies to nutrition and fitness.
Individuals will often state a substance, food, or exercise routine is bad simply based on the fact that it is unnatural. Common examples of this are artificial sweeteners, most supplements, refined sugar, GMO or non-organic foods, and even frozen foods. So why is this a fallacy? Well, it is simply too broad of a categorization system and doesn’t take the individual merits into account. To say that all unnatural things are bad would be saying that all human inventions are bad. Is the wheel “bad”? How about electricity? Or toilets? You get the point. Just because something is “unnatural” doesn’t allow us to immediately deem it worse than the natural alternative. We have to evaluate things based on the benefits they provide and the costs they create. While something like the wheel may clearly provide far more benefit than cost, individual evaluation can be more difficult in complex systems, such as the human body.
To understand the costs and benefits from various foods or exercises we have to look at empirical research. This form of research compares a group that is receiving the treatment of interest to a group that is not, or is at least taking less. By comparing these groups we can get an indication of the effects that the treatment has. I say “indication” because we can never prove, with full certainty, that something is true. In general, science only ever allows us to prove things false. For example, if I measure 100,000 people and they are all 5’8 I can not conclude that all people are 5'8. However, if I measure one person that is 5’9 I can prove, with certainty, that not all people are 5’8. Therefore, science, and especially nutrition and exercise science, often just provides us a best guess. For a topic to have a solid research backing it should have a large number of studies, on a variety of demographic groups, in a variety of locations, over a significant amount of time. This allows us to feel relatively certain (as certain as we can) about the results of a topic, and it’s generalizability to the population as a whole. When these conditions are met we can feel fairly comfortable moving away from simply judging based on “natural” or “unnatural”.
All this said, the classifications of natural or unnatural can actually have some use when there is very little research on a particular topic. In situations with relatively high uncertainty, it can often be best to start with the assumption that what is natural is the best, or the least harmful. This doesn’t apply in all situations, as there are a number of highly toxic, plant or animal substances that occur naturally. However, if a particular food, nutritional approach, or exercise routine has been used by humans for a long time, it is likely to have some benefits. Through the natural selection and competition of differing ideas, the people who have used safe and healthy practices will likely have been the people who survived and were successful. Given this selection mechanism, we can be fairly sure of the quality of practices or foods that have been used since ancient human societies. To introduce a modern food or practice, and claim it’s superiority, we should be able to present a significant amount of evidence demonstrating it’s long-term effects. Even with this evidence, it is often wise to choose a natural, time-tested option when possible and practical. A prime example of the benefits derived from this form of thinking can be seen in most whole-foods. Nutrition scientists previously assumed that the vitamins and minerals of whole foods could easily be repackaged in a supplement form without losing any benefits. However, we now know that whole foods offer a variety of health promoting substances, such as fiber, that can’t be easily isolated. It may be apparent that fruits and vegetables are healthy, but it is far more complex to say exactly why.
While assuming something is good simply because it is natural is clearly illogical (ie poisonous plants), that doesn’t mean that the naturalistic fallacy is a completely ridiculous protectionary mechanism when faced with uncertainty. There is significant merit in preferring ancient, natural options when possible. Adding something new, and therefore untested by time, to a complex system should always be taken with caution and possibly avoided if there is no significant benefit to be gained from its use. It is best to wait for a topic to be thoroughly studied before diverging from what natural selection, and thousands of years of trial and error, have provided humanity with.
Connor Crouse, PN1, PTS
Head Nutrition Coach