Scientific Myths of All Natural Medicine

October 3, 2018

Recently while discussing drug classifications and drug effects with my students, the All-Natural Medicine Myth was brought up.

the All-Natural Medicine Myth (a.k.a the Argumentum ad Naturam) reflects the tendency to believe something is good because it is natural—or conversely it is bad because it is unnatural. While I was talking to the class about different drugs, a student suggested that some drugs aren’t really that bad because they are natural.

As I questioned the student’s logic, it became apparent that the student believed “all natural” indicates “all good.” This sort of thinking isn’t uncommon. Various industries promote the type of information that suggests natural is the way to go; nature is your friend, and natural is always better. Americans and Europeans often agree with these claims (Rozin et al. 2004).  

Mandrake (written ‘ΜΑΝΔΡΑΓΟΡΑ’ in Greek capitals). Naples Dioscurides, seventh century

Approximately a decade ago I wrote an article discussing misconceptions associated with the All-Natural idea.

Since then I have written numerous articles on the topic, lectured extensively about related misconceptions, and have spoken on many occasions with students and colleagues regarding relevant matters.

While sometimes nature produces desirable outcomes, sometimes nature is lethal. “All-natural” is not synonymous with “all good.”

Belief that something is good or better because it is natural works in some contexts, for some people, but even those generally claiming that belief probably would agree that it lacks consistency.

Natural disasters or diseases are not your friends.  Natural diseases are often treated with synthetic treatments (“unnatural” treatments).

In some contexts (too many to mention), suggesting All Natural Medicine is better might be considered absurd. Consider the following: When collecting water from a stream, it is recommended that the water should be purified before drinking.

This purification of the water reflects chemical processes, and the water is usually purified using some type of tablet or water purifying device. These strategies alter the water’s natural state; it’s altered in an attempt to make it safer.

Would you be surprised to learn that some of the world’s most dangerous toxins are natural? They include ricin, abrin, botulinum, and strychnine—evolved chemical weapons used by organisms for self-defense and territorial expansion.

Plants and microbes carry a variety of toxic attack chemicals, and synthetic chemicals are no more likely to be toxic than natural ones (Silver 2006). According to molecular biologist Lee Silver, natural chemicals contained in organically grown coffee, pepper, mushrooms, apples, celery, potatoes, nutmeg, and carrots may present a greater risk of cancer in people than DDT, DDE, or Alar—three pesticides that are banned in the U.S. and many other countries.

Aectaldehyde, benzaldehyde, benzene, benzo (a) pyrene, benzofuran, caffeic acid, catechol, 1,2,5,6-dibenz (a) anthracene, ethylbenzene, formaldehyde, furan, furfural, hydroquinone, d-limonene, 4-methylcatechol, styrene, and toluene are naturally carcinogenic and potentially DNA-damaging chemicals found in a cup of certified organic coffee (Gold et al. 1992).

A case reported in 2006 involved 204 Americans who became seriously ill after eating freshly packaged spinach contaminated with a toxic bacteria found “naturally” in cow and pig manure (Silver 2007).

Paul Rozin, professor of psychology, has conducted research investigating people’s preference for natural in the context of food and medicine. Does All-Natural matter as much to people when it comes to medicine? Here’s an excerpt from an interview with Rozin (Hale 2016):

Q: Why do the majority of people prefer natural to artificial, even when they are informed that they are chemically identical, and do not differ with respect to influence on health and effectiveness?

A: Because natural is treated as a basic good thing, not subject to evidence, somewhat like belief in God for those who believe in God.

Q: Why do you think the preference for natural products is stronger for food than it is for medicine? Does this preference appear in cultures other than the American culture?

A: One possible reason is that medicines are for treating things where nature or human intervention has gone awry. For Americans, the distinction between medicine and food is vanishing. We know natural is preferred in U.S. and Western European nations, but there is little data from other parts of the world, especially from traditional cultures.

Research indicates the preference for natural is stronger for foods than for medicines. Natural entities are often thought to be healthier, more appealing to the senses, or better for the environment than entities that are not natural.

Natural is preferred just because it is viewed as inherently better—more moral, more aesthetic, or simply “right.” Research conducted by Rozin and colleagues (2004) found the majority of respondents in their study preferred a natural product over a corresponding commercial product. This preference did not change for most individuals even when they were told the natural and commercial products were chemically identical. Researchers concluded that preference wasn’t heavily reliant on concern with health or effectiveness but dependent on moral and aesthetic factors.  

glass bottle

In an effort to find out what people think of when they think “natural,” Rozin (2005) investigated two groups—American college students and adults in a Philadelphia jury pool. Participants were asked to rate the naturalness of different “natural” entities—before and after they were transformed by processes such as freezing, adding or removing components, mixing with other natural or unnatural entities, domestication, and genetic engineering.  The participants felt the biggest decrease in naturalness was due to the genetic modification of organisms.

Domestication—a human-driven activity that drastically changes genotype and phenotype—was considered less damaging to naturalness than genetic modification.

Lack of knowledge in the areas of biology and chemistry can lead to an array of misconceptions regarding the value and implications of nature and its consequences.

All ordinary matter (matter that reflects and absorbs light) consists of chemical elements. Every living molecule inside every living organism is created through chemical reactions. You, your pet, your family, your friends, and so on are a combination of chemicals.  Consider the amount of chemicals making up a 60 kg person: oxygen, 39 kg; carbon, 11kg; hydrogen, 6 kg; nitrogen, 2 kg; and calcium, 1 kg (Timberlake 1999).

Those chemicals make up approximately 98 percent of your body. Oxygen is found in water, carbohydrates, fats, and proteins. Carbon is found in carbohydrates, fats, and proteins. Hydrogen is found in water, carbohydrates, fats, and proteins.  Nitrogen is found in proteins, DNA, and RNA. The food, medicine, and liquids you consume are made up of chemicals. There is an extensive, systematic regulatory process involved with determining which chemicals are permitted for use in foods, medicines, and other substances.

“It is worth noting that, although it’s popular to complain about ‘all those synthetic chemicals’, this contrasts with increasing demand for them in and around the home e.g. oral contraceptives, mouthwash and decorating materials, and for gadgets which are manufactured using them, like mobile phones, computers and CDs,” notes Professor Andrew Cockburn, a toxicologist at the University of Newcastle. Natural is not inherently safer or better than unnatural.  The belief that natural is better is a faith-based belief.  



Gold, L.S., T.H. Slone, and B.R. Stern, et al. 1992. Rodent carcinogens: Setting priorities. Science 258: 261–265.

Hale, J. 2016. The Preference for “Natural.” Psych Central. Available at; accessed September 15, 2018.

Rozin, P. 2005. The meaning of natural: Process more important than content. American Psychological Society 16(8): 652–658.

Rozin, P., M. Spranca, and Z. Krieger, et al. 2004. Natural preference: Instrumental and ideational/moral motivations, and the contrast between foods and medicines. Appetite 43: 147–154.

Silver, L.M. 2006.  Challenging Nature. New York City, NY: Harper Collins.

———. 2007. Why Challenge Nature. Available online at; accessed September 16, 2018.

Timberlake, K.C. 1999. Chemistry: An Introduction to General, Organic & Biological Chemistry 7th edition. New York, NY: Harper Collins.