The Truth About “Natural Flavors”

Prior to becoming a functional medicine doctor, I started my career in the field of food science. Frankly, I loved it, but much of what I learned and saw there ultimately led me to exit the field and transition to working in natural health.

How can both of those things be true? How can I love something that ultimately led me away?

Read on to learn the story of how I entered, and then left, the field of food science to become a functional medicine doctor.

I chose to study food science in college because it seemed like the perfect mix of science, creativity and fun. I mean, who doesn’t love the idea of “playing with food” all day and calling it science?

For much of my adolescent life, I was already doing food science on my own. I was interested in eating healthy and cooking, and certainly appalled by the diversity and breadth of food items on the market that were completely unhealthy. It was not hard to see, even as a young person, that ultra-processed food items were not the way to long, vibrant life. As a teenager and athlete, I enjoyed concoting “alternative” recipes for “healthified” versions of common processed foods, inlcuding those that had taken on nostalgic appeal.

Sometimes I was successful, sometimes I wasn’t, but I learned a lot and had a lot of fun.

After starting my college career in engineering and quickly learning that the computer programming lifestyle was not for me, I took a turn in my study of science to pursue food science. I describe food science as a specialized form of chemical engineering that is focused on food. Food scientists, I’d explain, were responsible for finding recipes to keep cereal crunchy longer in milk, and come up with new, alternative protein sources. I was a vegan at the time, so I loved to wax poetic about meat alternatives.

Oh, how the times change.

As a hopeful young person, I envisioned myself working in R&D at a food company, designing formulations for healthier versions of popular products. I daydreamed about the next fast company like Annie’s Organics, or Morningstar Farms. I got involved in the local food office and connected with farmers and those who shared my passion for sustainable food growing practices. I interned in a lab where we used blueberry-derived antioxidants to kill cancer cells. I entered into R&D food competitions and won awards for “functional foods,” like a pea protein-based sausage alternative and a color-changing salt for those with hypertension. I was on a roll, and nothing was going to stop me. That is, until I graduated.

Through the end of my senior year and after graduation, I started working for a flavor company. First of all, I want to be clear that I have very fond memories of my time there, think well of the company owners/my bosses, and value the relationships I formed. It was a wonderful experience, I was treated very well, and I learned so much. The criticisms I carry from my time there have nothing to do with my team in flavor chemistry and everything to do with government regulations, marketing, and the food industry as a whole.

There are a few things to understand about flavor chemistry that I also want to cover, first. Food flavorings are built by mixing together individual chemicals to round out a flavor, kind of like how we combine rosemary, thyme, sage and oregano to make “poultry seasoning,” for example. It’s like filling in pieces of a puzzle to round out the flavor of a food. The chemicals chosen for this come from a process called gas chromatography, which is a chemical testing method that detects the presence of volatile compounds in food to figure out what is contributing to the flavor profile. These are complex processes and the gas chromatographer (GC) can’t do it all on its own; a trained flavorist fills in the gaps by identifying what might be missing from what the GC reports. Think about this role as like a sommelier who can identify the “grassy notes” in a young Pinot Grigio or “black pepper flavor” in a spicy zinfandel. The chemicals we mix together are ingredients, not reactants, meaning that they retain their characteristics and form even after being mixed together. They don’t form a chemical reaction like what occurs when mixing baking soda and vinegar; it’s more like, as I mentioned, mixing spices. They’re all there, together.

What goes into natural flavors?

And that is precisely the problem. My job in the lab involved making samples of these flavors sold by our company for manufacturers to try out before buying. Our flavorist-formulated flavors were built by yours truly and sent off to see if someone wanted to buy them. When they did, the warehouse guys would mix up large-scale portions of the flavors to send out for industrial use in everything from fizzy drinks to soft serve ice cream, to candy, popcorn and more.

My first problem with the job was that it was kind of boring. The end product was fun (mixing up two different types of strawberry flavoring was a fun experience for sure) but I didn’t love the solo work in a lab, with goggles and a ventilation hood and gloves to avoid chemical burns.

But, the second problem which ultimately led me out of food science was that when I traveled into the warehouse to refill my sample bottles in the lab, I was met with alarming warning labels on the drums of “natural” acetaldehyde and “natural” furfural. They said things like “do not ingest,” and “harmful if swallowed” and had skulls and crossbones on them. And there I was, using a pipette to mix them into a solvent (alcohol or MCT oily, or propylene glycol, for example) and then literally spooning it into my mouth to taste test the final product. Was I poisoning myself? I wondered.

The tipping point came when, while in the warehouse, I accidentally spilled natural methyl butyric acid on my shoe. It was so extraordinarly potent! It made my eyes water and my lungs spasm just being around my own foot. But the bottle in warehouse carried those alarming labels: “harmful if swallowed,” and “do not ingest.” If the spill on my shoe was making my eyes water, what was it doing to my insides? I wondered. My questions became even more important when I went home to where I was staying, with my pregnant sister, and I became concerned that I could potentially be exposing her and her unborn baby to harmful volatile chemicals.

I’d thought that by entering the food industry that I would be doing something good. After all, I was working with “natural” flavors, and wasn’t natural supposed to be better? But I also knew that alcohol can be considered “natural” even though it’s a carcinogen. Aspirin is naturally occurring in plants but can permanently damage children through Reye’s syndrome. Was my work with “natural chemicals” really in line with my desire to make healthier products to feed the world?

The problem with natural flavors

The more I looked into these chemicals, the more I became aware that they were not safe, not at all. Sure, I was diluting them down in the lab, but I also knew that the chemicals I was mixing up to make, say, strawberry flavoring were not the same as eating a fresh strawberry that grew in the ground. Moreover, I was starting to experience some concerning symptoms for myself, like weight gain, acne, and bloating. I also started experiencing cramping with my periods, which I had never dealt with prior.

Unsurprisingly, these symptoms disappeared when I left the office and entered graduate school instead. It wasn’t stress because again, the job was low-key and pretty fun. But chemical toxicants profoundly influence hormones, liver health, and inflammation, which were all systems of my body that were struggling because of my job.

Moreover, “natural” flavoring is exactly the same as artificial flavoring, which most consumers are already plenty wary of. The only difference is that the consitutent chemicals, such as furfural, for example, are derived from “natural” starting materials rather than synthesized through chemical reactions in a laboratory. Natural furfural comes as a byproduct from the biodiesel industry, derived from chaff. Synthetic furfural, on the other hand, is synthesized using catalysts like sulfuric acid in a laboratory setting. Regardless of formation, however, both are distilled and purified to be, truly, pure furfural. It’s the same thing just a different origin.

The flavor industry isn’t the only defunct area of our food system that concerns me, however. Even starting in my college program, our professors were honest about the fact that money, not consumer wellbeing, drives the industry. If we were to work in R&D, the #1 thing our bosses would be asking us to do was cut costs to cheaper ingredients. To model this, our capstone design project involved our professor immediately handing the projects back to us after submission, and instructing us to reformulate to cut costs by 30%. The way to do that was to transition to ultra-processed, refined, shelf-stable ingredients like corn and soy derivatives instead of fresh ones sourced from whole foods.

Why?

They’re cheap. They don’t “go bad.” They can be used as fillers to crowd out the expensive ingredients, only they come at the cost of diluting the flavor, too. They’re subsidized by the government and there are incentives for food companies to use them.

Well, friends, that’s where flavoring comes in. And coloring. “Natural” aside, those colors and flavors are designed to cover up the cover up. The food industry, contrary to what I was hoping to do, was all about tricking consumers into eating “junk food” and truly, toxic chemicals rather than helping to bolster up the health of Americans. Nobody was working to clean things up and make it healthier. Going agains the status quo would invariably get me fired. Yikes.

So, where does that leave us?

I personally consume processed foods still, from time to time. Even as a functional medicine doctor who has had personal experience working in the food industry and knowing all the crazy things that go on behind-the-scenes. But I try to strike a balance, for both myself and my family, between pursuit of “perfection” which does not exist, and enjoyment of life and novelty. That being said, I try not to let those ultra processed foods make up too teribly great of a proportion of my diet, instead emphasizing whole foods and fresh ingredients whenever I can. Not only do I feel better this way, but I’m naturally minimizing and displacing ingredients like those used to produce flavoring, which are truly harmful.

But what about you? How can you know what goes into these flavoring ingredients? How do you know what harm can be caused by them?

This is what natural flavors are made of, straight from my work in food science:

Natural flavoring is made from volatile organic compounds, things like aldehydes and -enols and -enals and other types of carbon-based molecules that can get really toxic, really quickly. The exact chemicals in different food items differ based on the construct of the flavor, whether the food has been cooked, etc.

Food companies don’t list out the ingredients in their flavoring because these recipes are considered to be “proprietary.” McDonald’s Vanilla Ice Cream has its own distinct flavor profile, separate from Breyer’s Vanilla Ice Cream, or what the food would taste like if you made dessert yourself from real cream and vanilla beans. However, many of the fundamentals are the same.

To find out what might be individual flavorings, start with Google. Search “VOC chemicals in __________” and fill in the blank with the food you’re looking for. Take strawberry flavoring, for example:

Then you’ll want to get the industrial-level safety information on these individual chemicals, such as furaneol, mesifurane, linalool, ethyl butanoate and more.

I recommend searching the database of real US flavor ingredient suppliers, such as Advanced Biotech, which offers a database of hundreds if not thousands of different chemicals that fall under the guise of “flavoring” ingredients. This is one of the major suppliers of industrial-level fragrance and flavoring chemicals that are food-grade, which I personally worked with when I was working as a food scientist in the flavor industry. Navigate to their website, hit the search function, and search these compounds by name. Here’s an example for the safety data sheet for acetaldehyde, which is found in many fruit flavors, especially citrus:

Keep in mind that if you don’t have a chemistry background, this can be confusing at times because the same chemicals can go by different names. For example, mesifurane which is listed as a VOC in strawberries, does not show up on the Advanced Biotech database. However, mesifurane also goes by the name 2,5-DIMETHYL-4-METHOXY-3(2H)-FURANONE. So, if you can’t find a particular chemical, look up (Google can again be a resource for this) other names for that chemical.

At the end of the day, you’re the one who ultimately gets to make the decision about what you put in your body. And, when food companies hide the ingredient list under the guise of “natural flavors,” it’s hiding information and getting in the way of informed consent. I take issue with that, which is why I’m sharing my experience and knowledge here, today.

Let me know in the comments: Did you know the truth about natural flavors? What are you comfortable consuming when it comes to natural flavors?

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I’m Dr. Alexandra MacKillop, a functional medicine physician, food scientist and nutrition expert.

I specialize in women’s health & hormones, addressing concerns like fertility, PCOS, endometriosis, dysmenorrhea (painful periods), PMS symptoms like bloating and mood changes and more.

If you’re looking for a new way to approach your health, I’m here to help you through it. Click to learn more.