We consumers are bombarded with advertisements for natural and organic products. There are websites and news stories beyond counting dedicated to sharing the following message: "man-made is bad and natural is good". The growing popularity of this belief shows that this subject is in dire need of clarification.
The idea that nature can harm us is not new. Have you ever heard of malaria, HIV, tuberculosis, botulism or tetanus? Why, then, are so many convinced that anything and everything natural is healthier for us than synthetic products? It's true that modern chemistry has brought us a number of toxic chemicals, like DDT and dioxins, but do you really think that nature's chemicals are any less harmful to you? In fact, the most toxic chemicals to humans are completely natural! Not only that, but there is much evidence that natural pesticides allowed in organic farming are just as toxic as synthetic pesticides. It would be wonderful if it were simply a black versus white topic.
Unfortunately, the natural versus synthetic debate falls very much in the gray region, and each and every chemical, or class of chemicals, must be considered on a case by case basis. To make the situation more frustrating, the number of useful and accessible resources for consumers is limited, since the majority of the "information" on the internet and in the news is unfounded and unreferenced. It's no wonder that this idea has been able to take hold so well! The purpose of this post is to briefly discuss the most common misunderstandings about natural and synthetic chemicals:
1. Synthetic chemicals are more toxic than natural chemicals.
2. Organically grown food is better for you because it's all natural.
3. Synthetic copies of natural chemicals are not as good for you.
I want to quickly mention that I neglected to point out the natural versus synthetic substitute controversies. The present poster products for this topic are sweeteners, and this is being covered by my colleague on our blog.
Before we get to the nitty gritty points we need some definitions since there is a huge discrepancy between what the terms "natural" and "synthetic" mean. This Venn Diagram helps to explain my definitions of natural, naturally derived and synthetic chemicals:
Natural vs. Synthetic Venn Diagram: Natural chemicals are produced by nature without any human intervention. Synthetic chemicals are made by humans using methods different than those nature uses, and these chemical structures may or may not be found in nature. This definition means a synthetic chemical can be made from a natural product (i.e. naturally derived). Note that in the food industry, "artificial" is used instead of "synthetic".
Misconception 1: Synthetic chemicals are more toxic than natural chemicals.
The two most toxic chemicals for humans, that we know of, are botulinum toxin and tetanospasmin. Botulism is caused by botulinum toxin, which is a protein and neurotoxin produced by bacteria spores. Tetanospasmin is a neurotoxin produced by bacteria that causes Tetanus. I created a bar graph to help us visualize the relative toxicities of the most toxic natural and synthetic chemicals to humans:
This graph shows that the most toxic natural chemical, botulinum toxin is over a million times more toxic than all of the synthetic chemicals, except dioxin. I apologize because the scale does not visually depict the relative amount of dioxin accurately, which is 0.00001 on this scale, but it still shows that even dioxin is substantially less toxic (about one hundred thousand times less)! The data, resources and further information about the chemicals shown in the bar graph can be found on my website.
This point is summed up well by researchers in California who studied natural and synthetic chemicals in the human diet in 2001 and wrote, "Among the agents identified as human carcinogens by the International Agency for Research in Cancer 62% occur naturally: 16 are natural chemicals, 11 are mixtures of natural chemicals, and 10 are infectious agents. Thus, the idea that a chemical is "safe" because it is natural, is not correct"
Misconception 2: Organically grown food is better for you because it's all natural
What are your thoughts on organic farming? Do you think it's healthier for us to eat? I wonder how many people who are pro-organic produce are aware of what organic farming entails, and that it still involves toxic chemicals? Before I go further, I need to mention that the amount of toxic chemicals, whether they are synthetic or natural, in our produce is negligible compared to other negative chemical and biological species we are exposed to. However, I see and hear people talk and write all the time about eating organic produce because it has less toxic chemicals so I feel compelled to include this. It is true that there are, and have been, a plethora of horrifying synthetic chemicals used in the agricultural industry, especially pesticides. These toxic chemicals are very important from an environmental perspective (leaching into soil and water, impacting animal life in the surrounding areas, etc.), but that is a whole other topic for discussion.
Organic farming can still use naturally derived pesticides - in fact, they can even use some synthetic pesticides too! If you don't believe me feel free to peruse the USDA's list of "Materials for Organic Crop Production". Research studies have shown that both organic and conventional food have the same nutritional content, and both contain residues of synthetic pesticides (albeit organic food does have less of these than conventional foods). There is much less known about the toxicity of natural and naturally derived pesticides, but some studies show that they can be just as harmful and carcinogenic. A risk assessment review of natural and synthetic pesticides has a great summary to conclude this point:
"1. The biological activity of a chemical is a function of its structure rather than its origin.
2. The biological properties, especially safety, of a chemical depend on its structure and the way in which the chemical is used (i.e. exposure).
3. Perceived risks are not always consistent with actual risks."
Further reading on organic and conventional foods: Review article on organically grown food, Study of carcinogenicity of naturally derived and synthetic pesticides.
Misconception 3: Synthetic copies of natural chemicals are not as good for you.
The chemical structure of a synthesized compound is exactly the same as the natural compound it is supposed to supplement, such as ascorbic acid, which is the primary form of Vitamin C. It will taste the same, smell the same, and it will function the same in your body. This is true for most cases, however sometimes there are additional and unintended products. For example, naturally derived Vitamin E is called d-?-tocopherol and synthetic Vitamin E is called dl-? -tocopherol. The difference between the two is that the "dl" refers to a mixture of both d- and l-?-tocopherol. There is no evidence that the "l" version is harmful to the human body at all, but it is about 1.4times less effective than naturally derived Vitamin E (Research Article). Since this is a debated topic, it's understandable that consumers may want to stick to natural sources of Vitamin E, but it does not mean that synthetic Vitamin E is toxic.
Inactive ingredients may differ between natural and synthetic products, such as additives, fillers, by-products, and additional naturally extracted chemicals (these may be active but are not the target compound) in naturally derived products. These are important to consider in any product, whether it is naturally derived or synthetic. For example, a number of synthetic food colorings have been banned due to suspected carcinogenicity.
Melatonin and butterbur extracts are interesting examples of naturally derived products that consumers must be wary of are. Melatonin is a popular natural "sleep aid", and naturally derived melatonin comes from the pineal glands of animals, which may contain viral material. Synthetic melatonin is molecularly exactly the same, and is much safer to take.
Butterbur are plants that contain an anti-inflammatory compound called petasin, which is a natural remedy for migraine treatment and prevention. Unfortunately, butterbur plants also contain pyrrolizidine alkaloids (PAs) that can cause severe liver damage, and thus it's important that butterbur extract is purified to remove PAs.
For further reading on synthetic versus natural chemicals, and to learn more about their syntheses, you should check out chapter 4 "Are NPs Different from Synthetic Chemicals?" in Richard Firn's Nature's Chemicals: The Natural Products that shaped our world.
Have I convinced you that natural vs. Synthetic chemicals is a gray matter?
We all have to accept that the natural vs synthetic chemical debate is not a black vs white issue, and it is actually a complicated and massive gray matter. Both natural and synthetic chemicals need to be considered on a case by case basis for our personal health, whether it's a drug, a food additive, or the pesticides being used on our crops.
Photo Credits: Oranges in the Venn Diagram by Evan-Amos Wikimedia Commons; Fruit in Venn Diagram by Marisa DeMeglio (Flickr) via Wikimedia Commons; Wine Making in Venn Diagram by Crosslers (Flickr) via Wikimedia Commons.