Are you human? Then your body doesn’t want so much sugar

Dr. Andrea Grayson
8 min readSep 29, 2020


How technologies in agriculture and food processing solved some problems and created others.

[photo by Kaique Rocha for Pexels]

With the advent of agricultural and food processing technologies over the past 100 years, we have been able to feed and grow the population. But those very technologies and many others have also led to a surge in chronic diseases, which kill more Americans than anything else.[1]

For the past 12,000 years or so, we humans have been cultivating food. We created tools for fishing and farming and systems for raising animals-which, by affording a steady supply of food, allowed us to build stable communities and grow the population.

Biologically, we haven’t changed much since then. Our digestive organs and bodily systems work the way they do because of 12,000+ years of perfecting the assimilation of the food that has been available: wild and cultivated game, fruits and vegetables.

But then we got clever--too clever, in fact, for our bodies to catch up. We developed technologies that would make growing food more efficient and preserve the harvest longer. And while those are important things for a growing population, they are not without consequences, both environmentally and physiologically. This article is focused on a couple of food technologies, and the unforeseen consequences they have on human physiology.

Unintended health consequence of technologies in the food system

The food system includes the entire cycle of how we access food, and includes:

Growing → Processing → Distributing → Marketing → Consuming → Disposing

Each aspect has been significantly impacted by a variety of technologies, each deserving of their own exploration. For the focus of this article, we’re going to look at the technologies associated with the processing aspect of the food system, and their impact on human health.

Food processing refers to any and all things that happen to a plant or animal from when it is harvested to the time it goes on a truck headed to a store near you.

In the pre-industrial age, the aim of food processing was to preserve the harvest and might have included drying, pickling, culturing, salting, or canning. Each of these technologies requires minimal processing, leaving the foods very close to their original state, preserving nutrients and often naturally occurring enzymes in the foods. This is important because our biology is optimized for whole foods, which have a diverse array of nutrients in differing combinations and amounts.

Food processing in the post-industrial, mechanized era, however, becomes an efficiency machine, enabling the mass production and storage of food to feed an ever-growing population. BUT, these processed foods react very differently in our bodies than whole foods do, and have a negative impact on our digestion, metabolism, nutrient absorption, and gut health, all of which leads to disease.

In particular, three food processing technologies have a noted adverse impact on human health include:

  • Industrially processed seed oils (canola, soybean, corn, sunflower, etc.)
  • Separating wheat germ from the flour
  • Refining sugar

Why vegetable oils and grain flours are considered harmful to human biology

Industrially processed seed oils, or vegetable oils, undergo an elaborate extraction process where they are first heated to extremely high heat, which causes them to oxidize (the opposite of an antioxidant) and removes naturally occurring enzymes in the seeds. Then, to extract the maximum amount of oil, the seeds are treated with a solvent such as hexane and processed again. Then the oils are deodorized, a process that creates trans fats, and colored with additional chemicals. Additionally, the composition of processed vegetable oils are primarily Omega 6 fatty acids, which are linked to inflammation.[2]

Omega 3 fatty acids which are found in fatty fish, and minimally processed seed oils like olive and flax, on the other hand, have numerous benefits including: protecting against (and a treatment for) depression; protect against heart disease, fighting inflammation, fighting autoimmune disease, and improving bone and joint health, to mention a few.[3]

The discovery that flour can be separated from the germ, and the invention of mechanized hulling, may be two of the greatest innovations in food technology. Prior to the ability to de-germ a grain by separating the bran and germ from the endosperm (flour part), wheat stores were vulnerable to quick rancidity because the germ has so many natural oils. Once the germ and bran are removed, the flour can be stored indefinitely, making it a prime ingredient for shelf-stable packaged goods and breads.

The problem with that, however, is that the flour has precious little nutrient value. And, perhaps more importantly, when flour is consumed separately from its other parts (germ and bran), flour so quickly raises our blood sugar that it is basically like eating sugar. Your cravings for bread are actually sugar cravings in disguise. To illustrate this point, we can look at the Glycemic Index, which refers to the rate at which a food turns to sugar in the bloodstream. A serving of whole wheat bread has a Glycemic Index rating of 74, while soft drinks can have ratings from 59, to as much as 70 depending on the serving size and source.[4]

So the technologies that enable us to preserve food solved one problem but created another.

The other food innovations that have backfired on our health are the technologies that allow us to mass-produce sugar from sugar cane and sugar beets.

Our brains are wired for several very important things: avoiding death (stay safe, don’t starve) and pursuing pleasure. It is also wired to be attracted to glucose — the sweet taste — because it is the primary fuel for the brain. All three of these elements — staying alive, pursuing pleasure, and fueling our brains — all come into play when we consume sugar.

The primary fuel for the brain is glucose, a simple sugar. The body makes glucose by breaking down more complex carbohydrates and starches (and protein when it runs out of those). But glucose, and its cousin fructose, are only available in their simple form in nature from only a few foods, including fresh fruits and honey.

If we ate according to the natural cycle of the seasons, we would only be eating regional fresh fruits in the summer/fall (changing it up in 3–4 week increments), and having honey would be a rare treat. These easy forms of energy are valuable in the summer when we tend to be more active.

But a variety of technologies, including plant hybridization and processing on an immense scale, allow us to have access to the brain-craving sweet taste all day long, year-round. The technologies that have enabled the mass production of sugar from sugar cane and sugar beets also allow it to be dried and stored, making it a prime ingredient for shelf-stable packaged foods. It is also worth noting that the amount of sugar used in those shelf-stable packaged foods went up exponentially in the 1980’s in response to the low-fat craze: packaged foods without fat are tasteless, so the increased use of sugar was to make the foods palatable. Now, 74% of foods in the supermarket have added sugar.[5]

So what’s wrong with having unlimited access to sweets every day? Here are 5 physiological reasons why you, a human, shouldn’t be eating so much sugar.

  1. Eating refined sugar causes inflammation, which is implicated in every chronic disease, including diabetes, heart disease, depression and Alzheimer’s.[4]
  2. Eating sugar causes your insulin levels to fluctuate, which can lead to diabetes and is linked to brain disorders such as Alzheimers and heart disease.[6] In the short term it is associated with everyday brain fog.[7]
  3. Sugar consumption causes a surge of cortisol, which can result in sustained inflammation.[8][9]
  4. We can become increasingly dependent on sweet treats for reward and pleasure, creating a feeling of addiction; this becomes a cycle of Dopamine dependency.[10][11][12]
  5. Sugar dependency can reduce emotional resiliency (because sugar is a quick-fix for stress).[13] We numb our stress by eating ice cream and cookies, thereby not learning to process our emotions and moderate our stress.

These are all physiological reasons why your body was not meant to consume refined sugar on a daily basis. When you insist on doing it anyway, the odds are that accumulated effects will take their toll with disease. Just like it takes 20+ years of smoking for the harms of tar and nicotine to show up as lung cancer, it takes 20+ years of abusing sugar for it to show up as heart disease, diabetes, cancer and depression, among others. In fact, sugar is a primary contributor to inflammation in the gut, which is associated which is associated with every chronic disease.

Why is it so hard to quit?

Having easy access to an abundance of sugar is certainly pleasurable, and is why it can be so hard to quit. In fact, in the process of trying to overcome my own sugar/carb addiction, I discovered that there are three distinct ways that we can become dependent on sugar:

  • Physiologically (blood sugar roller coaster, dopamine dependency, feeding bad bacteria in the gut)
  • Emotionally (as a way to defer emotional stress)
  • Habitually (our routines and rituals)

When you are trying to cut back or quit eating added sugar, it becomes much easier when you consider each of these areas, and address them with specific strategies. With your bases covered, the detox phase goes much easier; for most people, it lasts 3–10 days. Once the physiological pull is minimized, then you can focus on forming healthier emotional responses and habits.

And it can take several attempts to finally feel free: it took me almost 2 years of quitting and sliding back to feel like I finally had a “safe” relationship with sweets. By safe I mean that now I don’t feel like I need it, I can take-it-or-leave it. And, if I choose to have a piece of dark chocolate, it won’t always pull me back into a dependency (but sometimes it tries to, and I just use all the good habit-change tools to get back on track).

Summary: As humans, our biology is not meant to eat such frequent and concentrated amounts of sugar that have been made possible by food processing technologies. You can lower your risk of developing chronic disease by reducing the amount of sugar and refined carbohydrates you eat. Start by learning 10 ways to start reducing the amount of sugar you’re eating with the Quick-Start Guide.

Dr. Andrea Grayson specializes in behavior change communications and teaches in the Masters of Public Health program in the Larner College of Medicine at the University of Vermont. She is creator of Breaking Free from Sugar, a 4-week, research-based online program designed to break physiological, emotional and habitual dependencies on sugar. October, 2020 Program options include self-paced and with weekly coaching.



Additional Resources

Kresser, Chris How industrial seed oils are making us sick.

Russo, Gian Luigi, Dietary n-6 and n-3 polyunsaturated fatty acids: from biochemistry to clinical implications in cardiovascular prevention

Grosso, Guiseppe, et. al, Omega-3 Fatty Acids and Depression: Scientific Evidence and Biological Mechanisms

Healthline, 17 Science-Based Benefits of Omega-3 Fatty Acids

Aronson, Dina, Cortisol — Its Role in Stress, Inflammation, and Indications for Diet Therapy

Originally published at on September 29, 2020.



Dr. Andrea Grayson

Andrea is a Communications Consultant and Professor in the MPH program at UVM. She is creator of More info at: