Carbohydrate Addiction: How Birdseeds and refined sugars may alter Brain Chemistry

Carbohydrate Addiction:
How Birdseeds and refined sugars may alter Brain Chemistry

In the previous article I eluded to the fact that high-carb diets can disrupt our brain chemistry. This will be the subject of this article.
In the practical guide to Paleo I distinguished which foods are high in carbohydrates.
I also stated that some high-carb foods may be consumed in moderation (like fruits, nuts, starchy vegetables/roots, dark chocolate and red wine) and that others should be avoided altogether. These foods to avoid include ground-up birdseeds (wheat and other grains in the form of breads, pasta, cake, cookies and similar processed foods), sugar water (soda’s/sugary beverages), candy and rice. In this article I will focus on one of the reasons (among other reasons) why these foods should be avoided. In this text I will cover the neurological part of the story. I will explain how high-carb processed foods mess with the way our brain functions and results in an impaired emotional state (how we feel), as well as a numbed motivation in striving after worthwhile goals in life.

Personally, I like to feel Joyous for no reason and be excited to take action towards my aspirations when I wake up in the morning. This is how I felt when I was a kid, but for some reason, this zest for life left me as I grew older. I didn’t know why it happened, but it did and it also happened to most of the other people around me, so I figured that it was just a normal part of growing up. Nothing could be further from the truth.

Recent research has shown that brain chemistry is influenced by food intake and that it is possible that certain foods (high in carbohydrates) can be addicting. Let us start by investigating the:

Components of addiction

Avena, Rada and Hoebel (2008) describe four components to addiction:
Bingeing, withdrawal symptoms, craving and cross-sensitization.
Bingeing means that an animal will consume excessively large amounts of the object of addiction. Withdrawal includes symptoms of anxiety and depression. Craving indicates an intense desire for the object of addiction when it is not available. Cross-sensitization is when an animal is becoming more prone to use other addictive substances as a result of being addicted to one particular thing (an animal addicted to sugar will also show signs of being more prone to other addictive substances like drugs).
If these four components are present, we can speak of addiction. Furthermore, addiction rests on a lack of conscious control by an individual. It relies on the impulsivity to indulge in the object of addiction.

In everyday language, it means: “I do it because it makes me feel good.”

People engage in addictive behaviour because it boosts their emotional state in the short-term, while it has negative effects in the long-term. Let’s explore how this works in the brain. First (1) I shall cover the most important brain system that is involved in addiction, then (2) I shall go into how brain processes are influenced by high-carb foods (and other addictive substances and behaviours) and after that (3) I shall elaborate on what real-world implications these have for us as human beings.

The Endogenous Reward System

There is a set of brain structures that are believed to be operating in concert in assessing the probability of rewards and punishments in any given situation (Boksem & Tops, 2008). This set of brain structures is referred to as the Endogenous Reward System and it consists of midbrain Dopamine neurons, the Orbitofrontal Cortex, the Basolateral Amygdala, the Insula, the Anterior Cingulate Cortex, the Nucleus Accumbens Septi and the Ventral Tegmental Area (VTA). This reward system makes evaluations about the expected rewards and costs of engaging in a particular behaviour and motivates the individual into action if the outcome of these evaluations is considered to be valuable.

In other words, the system weighs the likelihood of reward against the energetic costs of engaging in the behaviour and if the rewards outweigh the costs, the person will act out the behaviour. The chemical that operates within this system is the neurotransmitter Dopamine. Dopaminergic reactions between brain cells (neurons) are what motivate us into action and steer us in the direction of outcomes that will be rewarding for us.
According to Jeanette Norden PhD (2007): “This is the system that allows us to tap into the Joy of life and allows us to engage in the world.”

The Reward System is what modulates our motivation levels to engage in life’s activities. When it functions optimally, it steers us into the direction of things we value and Dopamine (probably in concert with opioid systems and other neurotransmitters like Norepinephrine) is what drives our motivation to fuel our actions to go after what we want and value.
However, it is possible for this system to be disrupted by substances and behaviours that influence Dopamine release in these brain structures.
Science has revealed that all addictive substances involve projections from the Ventral Tegmental Area (VTA) to the Nucleus Accumbens Septi (Nacc) (Norden, 2007) in the Reward System. Avena, Rada and Hoebel (2008) have found that sugar does just that and thus, is a candidate for an addictive substance.

High-carb foods may release excessive amountsof neurotransmitter in the brain

Like I stated, the Reward System steers us in the direction of things we value.
Food is a pretty important thing for humans, so it should come to no surprise that Dopamine pathways in the brain are influenced by food.

Back in Paleo/Primal human’s time, carbohydrates were very scarce in the foods humans found while hunting and foraging. Fruits (high-carb food) were seasonal and mostly available in summer. Root starches (high-carb food) were hard to eat as you have to boil them first. Honey (high-carb food) was only reserved for those brave enough to mess with beehives (and lucky enough to find them). The staple foods consisted of meat, fish, fowl and eggs which are high in fat and protein. Vegetables contain little to moderate amounts of carbohydrates. Agriculture was not invented yet and Coke and Pepsi were not around either. Carbohydrates were a lot scarcer as compared to the present day. As a result of this, our Reward System notified us whenever we found high-carb foods like fruits and honey and urged us to indulge in them. Better to consume all fruits in summer as they will not be available in winter. Our ancestors simply did not have the same access to high-carb foods that we have today.

The research of Avena et al. (2008) may give us an indication of what happens to an animal’s brain chemistry when it is fed man-made foods high in carbohydrates. In most of these experiments, rats were divided in four groups: (1) rats that had intermittent access to sugar and chow (regular rat feed), (2) rats that had unlimited access to sugar and chow, (3) rats that had intermittent access to chow and (4) rats that had unlimited access to chow. The intermittent access groups were deprived of food for 12 hours, whereas the unlimited access groups had food available continually. Rats in the first group were found to binge more (Avena and Hoebel, unpublished) than rats in the second group.

Also, rats in the first group showed more signs of withdrawal symptoms:

These sugar dependent rats show signs of anxiety and depression.

Additionally, research also supported the other two components of addiction (craving and cross-sensitization) (Avena, 2008). These findings suggest sugar to be a potentially addictive substance for rats, especially under conditions of food deprivation. Also, alterations in brain chemistry (involving Dopamine, Opioids and Acetylcholine) similar to those in drug addiction are found in rats that are addicted to sugar.

One limitation of these experiments is that they are done with rats. A rat’s natural diet is very different from a human’s diet. In fact, when investigating the rat diet, we find that the term ‘birdseeds’ is quite incomplete, RODENTS EAT IT TOO. A rat is quite a diverse eater; they are omnivores and can eat pretty much any type of food.
Second, the substance that was used consisted of either glucose or sucrose (which breaks down into one fructose and one glucose molecule) provided in a liquid to the rats. This makes the used substance likened to a soda/sugary beverage, a liquid with a concentrated dose of just carbohydrates. I don’t want to implicate that which has not been proven yet, so there may be a possibility that these findings cannot be generalised to humans and not be generalised to all high-carb foods.
However, these findings do raise some very interesting questions that are worth investigating. What if a high-carb diet DOES alter our brain chemistry? I know I’m not going to sit around for the research to roll in and confirm these ideas that I have EXPERIENCED to be true. Why not do a n=1 experiment and see what happens when you cut way back on high-carb foods? It certainly is an area worth investigating.

“But wait a minute, I’m not addicted!”

If we look at the components of addiction and at most peoples eating style, it becomes quite clear that most of us don’t qualify as being addicted to sugar. However, that does not necessarily mean that we are free from the detrimental effects that high-carb eating may bring. Just because we are not hospitalized and ‘out-of-control’ addicts does not imply that we do not have any of these addiction symptoms (although in milder forms). Aside from that, it’s kind of hard to tell whether we are addicted to high-carb or not, as people have constant access to high-carb foods. The only way to find out whether you have withdrawal symptoms is to limit high-carb foods for a while.

When I started eating less high-carb foods when transitioning into the Native Human Eating Style (Paleo/Primal), I found that I was HIGHLY dependent and addicted to carbohydrates. I found that at first my motivation and mood levels dropped significantly when ditching grains and refined sugars. This was not because of the new foods I started eating, but because I stopped eating the addictive substances that are high-carb foods. It was an insane emotional crash that took a couple months to recover from. You can read my journey about it here. Fortunately, my brain chemistry restored itself and (because I had studied the neurology of all this) I intuited what was going on with me and I managed to pull thru the emotional and energetic low and stick to eating flawless Paleo/Primal. It wasn’t easy and my family and friends thought I was fucking crazy for persisting with it.


Dopamine Receptor Balance

I have not gotten into the specifics of how our brain chemistry is altered by sugar (and other addictive substances and behaviours) yet, so I will proceed in explaining what happens in our brains during the addiction process. Let’s start with the basics of neurotransmission in the brain.

Activity and connections between neurons (brain cells) are made by means of neurotransmission. Neurons have axons that they use to connect with other neurons. This axon (which sort of looks like a tail or tentacle) connects with another neuron and between these two neurons a space (called a cleft or synapse) is created. If the axon of the first neuron gives a positive electrical signal (called an action potential), amounts of neurotransmitter are released into the cleft/synapse.

On the other side of the cleft/synapse, the other neuron has neurotransmitter receptors to which the neurotransmitters can bind. This binding process stimulates electrical activity in the second neuron, and might further facilitate an action potential in the next string of neurons. After the binding process, some of the neurotransmitter goes back into the axon of the first neuron (this process is called re-uptake) and others are broken down in the cleft/synapse.

Now, that’s a lot of neurological terms (if you’re new to brain chemistry), so I want to focus on three of these, namely:

  • (A) the amount of neurotransmitter present in the axon of the first (pre-synaptic) neuron
  • (B) the amount of neurotransmitter present in the cleft and
  • (C) the sensitivity of the neurotransmitter receptors of the second (post-synaptic) neuron.

A healthy neurotransmitter receptor balance is when the brain has adequate amounts of neurotransmitter reserves (A) and receptors are sensitive (C) enough to natural amounts of neurotransmitter that are being released into the cleft (B) under normal everyday circumstances. When there is a healthy neurotransmitter receptor balance (among other things), an animal will feel good and be motivated to engage actively in life.


Overstimulation leads to neurotransmitter deficiencies

In the addiction process, something happens to the neurotransmitter receptor balance. Addictive substances and behaviours release high concentrations of Dopamine within the Reward System. For a short time period, amounts of Dopamine in the clefts (B) are elevated. The person experiences this as an emotional high or a feeling of euphoria (Norden, 2007). This emotional high is followed by a low, because the high doses of Dopamine deplete the amount of neurotransmitter present in the axons of the pre-synaptic neurons (A).
In other words, addictive substances and behaviours deplete neurotransmitter reserves by releasing a large dose of them in a short period of time. As a result of this, during the period following the emotional high, less Dopamine will be released during natural everyday activity. Also, there are more long-term effects of these excessive high doses of Dopamine that are released into the synaptic cleft (B). During the emotional high, post-synaptic Dopamine receptors (C) have a lot of neurotransmitter binding to them. In reaction to this, post-synaptic neurons will down-regulate the amount of receptors, as well as the sensitivity (C) of those receptors (Norden, 2007). This is how a tolerance is built up to an addictive substance. “Tolerance is a gradual decrease in responsiveness, such that more of the substance is needed to produce the same effect.” (McSweeney et al., 2005, as described in Avena et. al., 2008).

In other words, you need more of the object of addiction to achieve the same emotional high as the initial hit. This increases craving, which leads to more bingeing and keeps the addiction in place. In the meantime, Dopamine receptors get more and more desensitized and the neurotransmitter receptor balance gets worse and worse. In emotional experience, you grow more and more numb and you become less and less motivated and excited by life.


Restoring receptor sensitivity & natural neurotransmitter reserves

The only way to restore healthy neurotransmitter receptor balance is to quit the addiction and to endure the emotional low of withdrawal symptoms. After a while (couple weeks or months, depending on the severity of the neurotransmitter receptor imbalance), receptor sensitivity and neurotransmitter reserve restore themselves. This is not a pleasurable experience and a lot of people relapse back into addiction because they can’t stand the emotional low (plus, they also need to deal with other responsibilities and people in life). Everyone likes to be around a fun, joyous and excited person, not someone in an emotional low, which makes it more difficult for a person to quit. In the end, when a healthy neurotransmitter receptor balance restores itself, it’s totally worth it though, as stable energy levels, positive emotionality and motivation will eventually re-emerge. When natural Dopamine levels and receptor sensitivity are back, motivation to engage in the world is back as well.


Motivation is Healthy Wanting: a Functional Reward System

But that’s not the end of it, as it turns out there are more brain chemicals that may be effected by high sugar intake. In neuropsychology, a distinction is made between ‘wanting’ and ‘liking’ of an acquired reward. Dopamine covers the wanting part (the pursuit of a reward & what sets us in motion to go after what we want), but Opioids and GABA/benzodiazepine systems are found to be associated with ‘liking’ (Berridge, 1996), the experience of attainment and the pleasure of consuming the reward.

Enjoyment is Healthy Liking

How come people in today’s society are so dissatisfied with what they have, even though they have more luxuries than ever before?
Here’s your answer. Enjoyment and Appreciation of goods has little to do with what you’ve got materially and EVERYTHING to do with healthy and functional brain chemistry.
Neurological systems like the Reward System and the Opioid System (as well as the Locus-Coruleus Norepinephrine System and other neurotransmitters like Serotonin, etc.) are quite complex and interact with each other in our brains and create our experience of life. Obviously, it isn’t as simple to say things like: Dopamine is the brain chemical for motivation, Opioids are for pleasure/pain, Serotonin is for our moods, and Norepinephrine is for arousal. These systems all interact with each other and it’s all about what behavioural tendencies are observed to be correlated with activity and deficiencies in certain neurotransmitters.
In spite of the complexity, I intuit there is much value in understanding the processes I’ve described above and trying out new things and seeing how they affect your experience of life. See if you can identify a couple of addictions you might have, make a conscious choice to quit that addictive substance or behaviour for a prolonged time period, and then see what happens. You may end up with an improved quality of life.
To conclude this article I will state the following:

A distinction can be made between two ways to live life:

You can either actively explore, try lots of different things and
find out what works by first-hand experience.


You can wait for 100% proven scientific findings
to arrive until you try something new.

I love science and I am very thankful for the kind of new findings that Avena, Rada and Hoebel (2008) (and many other great scientists in other fields) have brought to the table. However, it is a fact that science has so much more to uncover and that there are things in life that science may not even be able to investigate. I know I cannot let science be my sole guide for action, as I would be missing out on so many possibilities and opportunities that might enhance the quality of my life. The Native Human Eating Style (paleo/primal) was one such thing and I’m glad I applied it in my life.

Edje Noh

Reference List

Avena, N.M., Rada, P. & Hoebel, B.G. (2008). Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neuroscience and Biobehavioral Reviews. 32(1): 20–39.

Berridge, K.C. (1996). Food reward: brain substrates of wanting and liking. Neuroscience and Biobehavioral Reviews. 20 (1):1-25.

Boksem, M.A.S. & Tops, M. (2008). Mental Fatigue: costs and benefits. Brain Research Reviews, 59, 125-139.

Colantuoni, C., Rada, P., McCarthy, J., Patten, C., Avena, N.M., Chadeayne, A. & Hoebel B.G. (2002). Evidence that intermittent, excessive sugar intake causes endogenous opioid dependence. Obesity Research 10 (6): 478-88.

Norden, J. (2007). Understanding the Brain, TTC Video.


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2 Responses to Carbohydrate Addiction: How Birdseeds and refined sugars may alter Brain Chemistry

  1. $exyArabMan says:

    I’m addicted to reading about game and self improvement. lol– I think that counts!

    • edwards87 says:

      Certainly, Intellectualism is definitely a form of addiction. It’s the whole trade-off between concepts and experience Eckhart Tolle (and many other spiritual teachings) talk about. By conceptualizing everything and having all your attention focused on that mental process distracts away from your present experience (how you feel in your body). Thinking and being in the mind becomes an escape from negative feelings. For the long-term, it’s wiser to face those feelings rather than using addictions to mood alter (change your emotional state with addictive behaviors).

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