Food Science and Nutrition Myths: Is Natural Food Better for Us?

From the Lecture Series: Medical Myths, Lies, and Half-Truths — What We Think We Know May Be Hurting Us

By Steven Novella, MD, Yale School of Medicine

Is natural food better for us? The appeal of natural versus artificial or synthetic comes from our exposure to the industrial society that we’ve built for ourselves. Surrounded by chemicals and artificial and synthetic products, being natural has an automatic appeal, although this appeal also goes back long in our history.

Woman buying fruits and vegetables at local food market
(Image: Matej Kastelic/Shutterstock)

Is Natural Food Better for Us? What Does “Natural” Even Mean?

The question “Is natural food better for us?” is more complicated than a simple yes or no answer can address. There’s something psychologically appealing about the notion of being all-natural; it also partly stems from a fear of things being tainted. Emotionally, we respond in disgust to things that feel as if they are contaminants or artificial. The word “chemicals” is often used as a pejorative, as if something that is a chemical is distinct from something natural.

Therefore, the word and the concept of “natural” is largely an emotional appeal. You may also be surprised that the word itself is very loosely regulated. There is very little or vague regulation about the use of the word “natural” and can be applied to most things, no strict criteria for slapping on the label “natural’ to a product. It doesn’t mean as much as people think when it appears on packaging or marketing.

This is a transcript from the video series Medical Myths, Lies, and Half-Truths: What We Think We Know May Be Hurting Us. Watch it now, on Wondrium.

The Dangers of Natural

What are the implications of being natural versus not being natural to the products that we use or to human health? There are many poisons in nature. Being natural is no guarantee of being safe or healthy. Hemlock, cyanide, arsenic, many venoms, both animal and insect, and other derivations from nature are terrible poisons that evolved to be deadly poisons to humans and other animals.

Many plants—in their natural form—contain poisonous substances. It is not recommended that you go into your backyard and eat a random plant without knowing what it is. You’re likely to get an upset stomach and if you choose poorly, you may even be seriously harmed.

Only a small subset of the plants encountered in nature is good for you and would make good food. Although, interestingly, a plant that many people think is highly toxic, poinsettias, turns out to be a myth. It’s only very mildly toxic, and it certainly isn’t a food. There are numerous case reports of children and pets eating entire poinsettia plants without leading to any serious outcomes.

Learn more about how natural isn’t always better for you

Natural Foods That Can Harm You

There are other poisons in nature still. Even the foods that we eat may have some hidden poisons, like mushrooms. Some are harmless, but if you’re not careful about the mushrooms you eat, you may encounter the death cap mushroom, which is sometimes accidentally eaten. This contains a deadly poison that can lead to death in many cases.

You may have heard that you shouldn’t eat green potato chips because they’re poisonous. It turns out that while one potato chip is not going to harm you, this warning is not a myth. Green potatoes contain a toxin called glycoalkaloids. There are case reports of people becoming very sick from eating green potatoes and even dying in some cases.

Raw cashews
Raw cashews have been steamed and cooked to remove a poison called urushiol. (Image: marekuliasz/Shutterstock)

Raw cashews also contain a poison called urushiol. You may think you have bought raw cashews from the store. There are cashews marketed as “raw,” but it turns out that raw cashews that you buy are not entirely raw.

They have been steamed and cooked to some degree. They’re not roasted, but they have to be at least steamed to eliminate or remove most of the urushiol from the cashews because it’s a poison. It’s the same poison that occurs in poison ivy and can result in a serious adverse allergic reaction.

Other foods like almonds, cherry pits, and apple seeds contain cyanide. Pufferfish or fugu, which is a delicacy in Japan and elsewhere, is a fish that contains a deadly toxin called tetrodotoxin. It can paralyze and kill you. The fish must be prepared specially to make sure that none of the tissue which contains a significant amount of this tetrodotoxin is included in the final product. But, one error on the part of the chef can lead to accidental poisoning.

Tomato plants—the plants themselves, not the tomatoes—also contain a glycoalkaloid. Although some people use them as a spice in cooking, they must be careful to remove that plant from the final product so that no one eats it.

Learn more the importance of whole foods and fiber

Other Issues with Natural Food

Among the many varieties of plants, some plants are foods that are not poisons, but the chemicals they produce may have reactions inside our bodies. For example, some plants, most notably soy, but also broccoli and wheat germ, contain agents called phytoestrogens that have hormonal activity in humans.

These are probably safe. There isn’t much of a health concern about the estrogen-like effects of soy and other plants that contain phytoestrogens. However, there haven’t been definitive studies. For women, the evidence is sufficient to say there is no health risk from phytoestrogens; however, the jury is still out a bit for young children and perhaps for male fertility. In those groups, more research is needed and there is some indication that there may be actual health effects. This could justify caution in using excessive amounts or large amounts of soy in prepubescent children, for example.

Is there a specific definition that we can give that has real meaning to the word “natural?” Click To Tweet

But, the deeper question here beyond what the word “natural” means or how it’s regulated is how we would define it. Is there a specific definition that we can give that has real meaning to the word “natural?” Most people would assume that being natural means that it occurs in nature, which superficially sounds reasonable. But, when we dig a little deeper on that we realize that that’s not a clear definition either.

For example, all elements occur in nature—iron, oxygen, and carbon. Therefore, you might assume that anything made out of those elements is also natural. But, most people likely won’t accept that as a reasonable definition.

Learn more about the connection between food and health outcomes

The Science of Food

Healthy food in heart and chemical elements on blackboard
(Image: udra11/Shutterstock)

What if we take it up one level to molecules and chemicals? Therefore, any molecule which occurs in nature is natural. Those molecules that do not occur or are not found in things like plants and animals are therefore unnatural.

However, that leads to another question: What about a molecule that is manufactured or synthesized, but is identical to a molecule that occurs in nature? Is the synthetic molecule natural because it’s identical to a molecule that occurs in nature or does the origin also matter? Does the actual physical molecule itself, not just its chemical structure, have to derive from something natural like a plant or animal?

For example, this comes up concerning vitamins. You could take a vitamin C molecule that is derived from rose hips and a vitamin C molecule that was synthesized in a laboratory. The chemicals are identical. There’s no test you can do to distinguish one molecule from the other. Is one, therefore, natural and the other one unnatural? If so, then what does that mean?

Learn more about how large amounts of sugar lead to hyperactivity in children

The Slippery-Slope of Natural Claims

Green rubber stamp with text Natural product 100% icon
(Image: graphego/Shutterstock)

We can also consider degrees of processing. If you take something that derives from nature—a plant or an animal—and alter it, is there any amount of processing through manipulation that would cross a line into no longer being natural?

What about, for example, just simple mechanical processing like chopping or grinding? What about mixing that with other substances or isolating a piece of it from its source? If I take a plant, for example, and isolate one chemical or one molecule from the hundreds that occur within that plant, is that plant-derived molecule still natural or does the isolation process transform it into something manufactured?

On the other hand, some changes that occur in this fashion, such as making hydrogenated fats—transforming fats into a less healthy version. Hydrogenated fats will increase your risk of heart disease, for example. That’s another case where processing makes something less healthy. It’s not the processing itself or the degree to which something is natural that seems to matter; rather, it’s simply what the final chemical structure is and how it responds in our body.

To put all of this together, the term “natural” is often used as a substitute for concepts and virtues that we’re after—the notion that we want our food to be safe and nutritious, things to be effective, pure, and wholesome. But, replacing evidence and logic for those things—those virtues that we want—with a shortcut, a label of being “natural,” is counterproductive. It encourages us not to think carefully about the evidence behind the claims that we are hearing.

Common Questions About Natural Food in a new tab)

Q: Is there a benefit to eating natural food?

There is much controversy based on the question of whether the organic variety of pesticides still used on natural foods may harm the environment worse than conventional forms.

Q: Why is organic food more expensive?

Organic food is generally more expensive because much less is produced per harvest and the techniques and production methods are said to cost more.

Q: Are there fewer pesticides on organic produce?

There are generally less conventional pesticides but equally as many organic pesticides. Studies are not clear whether organic pesticides are safer.

Q: What determines whether a food is organic or natural?

Organic foods are produced without any synthetic or man-made chemicals or irradiation techniques.

This article was updated on August 14, 2020

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