The Psychology Behind Sugar Addictions

NOTE: This is a long research article I wrote below, so I will highlight a few main points first if you don’t feel like reading the whole thing. If you have the time and would like to read it all, please do!

 

Summary: Why is Sugar Addictive?

 

1. We “Feel Better” When We Eat It. Eating sugar increases the serotonin levels in the body, which is a calming and mood elevating neurotransmitter. Serotonin plays an important part in regulating pain levels and sleep cycles, and it is an anti-depressant. When sugar levels increase, serotonin levels rise and individuals can feel better about themselves both physically and mentally.
2. It’s as Addictive As Drugs Like Cocaine. Ingesting sugar can also increase dopamine levels, which is also happens when someone ingests cocaine or other addictive drugs. This can cause a binge and withdrawal cycle and lead to a dependence on the substance.
3. The Brain Thinks it Is Rewarding. The orbitofrontal cortex is an area in the front of the brain where humans process rewards, and this is activated when someone consumes sugar. Therefore, sugar is seen as rewarding to the body.

 

The Psychology Behind Sugar Addictions

 

We find sugar everywhere today. In the supermarket it hides between cookies, cakes, donuts, candy, soda, and other foods we would never think to look. With all these tasty delicacies sitting around, it is hard to stop ourselves from eating it all the time. Recent psychology studies show that there might be valid reasons as to why we cannot stop eating sweets. Studies that look at the biological and chemical properties of sugar when compared to human eating habits find astonishing results. Sugar is an addictive substance.

There are three types of food molecules that can enter the body: fat, carbohydrates, and protein. Sugar is categorized as a carbohydrate that is composed of hydrogen, carbon, and oxygen. Compared to other carbohydrates, sugar is a relatively simple molecule, so it is easier to break down in the body’s intestinal system. We can find many different forms of sugar in the world today. This can include anything from simple white cane sugar (what we usually use in baked goods) to the more exotic sugars like agave nectar or molasses. All of these substances contain the same mixture of simple sugars, which are glucose, fructose, and sucrose. These three types of sugars can be mixed and matched in order to create a unique combination. For example, granulated sugar is 100% sucrose while honey is 50% fructose, 45% glucose, and 5% sucrose.  These different molecules all make up what we call “sugar.”

An addiction is something that causes psychological dependence, so it is a mental and cognitive problem in addition to a physical ailment (Avena, 2008). According to the Diagnostic and Statistical Manual of Mental Disorders, an addiction can now be classified as a dependence. Dependence is “characterized by compulsive, sometimes uncontrollable, behaviors that occur at the expense of other activities and intensify with repeated access” (Avena, 2008). In regards to sugar, this means that eating sugar continuously and uncontrollably can cause daily activities to suffer. In order to be diagnosed with a sugar addiction, psychologists and doctors look at three different signs: bingeing, withdrawal, and craving (Diagnostic and statistical manual of mental disorders, 2000). Just one of these symptoms can indicate a start to an addiction, but all three combined points to a serious dependence on a certain substance. Usually we think of alcohol and drugs as addictive substances, but sugar is a very real addiction, too.

Eating sugar increases the serotonin levels in the body, which is a calming and mood elevating neurotransmitter (Fortuna, 2010). Serotonin plays an important part in regulating pain levels and sleep cycles, and it is an anti-depressant. When sugar levels increase, serotonin levels rise and individuals can feel better about themselves both physically and mentally. Many times we think of cookies and ice cream as comfort food, so this could be one reason why some people have a hard time staying away from these sweets.

Ingesting sugar can also increase dopamine levels. Research has proven that addictive substances like cocaine and heroine cause “elevated extracellular dopamine levels in the nucleus accumbens” (Fortuna, 2010). This same process occurs when sugar-rich foods are ingested. It has also been found that the dopamine receptors are critical for people to experience pleasure for normal life events like watching movies, exercising, or reading books (Fortuna, 2010). A deficiency in this receptor can lead to depression, so many times those who are deficient in the dopamine receptors may turn to drugs or sugar for pleasure. A deficiency in the receptor has also been linked to a variety of disorders like alcoholism, bulimia, or binge eating.

One study performed on rats tested why people have a hard time slowing their sugar intake, and the results showed that dopamine was released when sugar was ingested. In the study, rats were deprived of food daily for twelve hours. Then, when their circadian rhythm was normal, they were given a twelve-hour access to a sugar solution and chow. This resulted in the rats learning how to eat copious amount of the sugar solution, especially towards the start of the day. After a month of this feeding cycle, the rats showed many behavioral similarities to those with drug addictions. For example, binging and opiate-like withdrawal occurred along with signs of depression and anxiety. Each time the rats drank the sugar solution, there was a release in the extracellular dopamine (DA) in the nucleus accumbens (NAc). This is a typical effect of drug abuse, and this overtime can lead to changes in the availability of the DA receptors (Avena, 2008).

After a carbohydrate-rich meal, one can expect to be sleepy for hours as tryptophan enters the brain and dominates the LNAA, Large Neural Amino Acid (Fortuna, 2010). Because sugar is a carbohydrate that is easily broken down in the body, the effects of sugar happen very quickly. This happens because blood glucose levels rise after a carbohydrate-rich meal, which releases the hormone insulin. According to Fortuna, “as it turns out, all of the amino acids that compete with tryptophan for entry through the LNAA are sensitized to insulin…when this happens the ordinarily scarce tryptophan becomes the most abundant amino acid in the brain.”

Intermittent sugar access can also act through the opioids in the brain.  The changes in the opioid systems of the brain caused by eating sugar lead to the addiction-like signs of withdrawal. “Intermittent, excessive intake of sugar can have dopaminergic, cholinergic, and opioid effects that are similar to psychostimulants and opiates, albeit smaller in magnitude” (Avena, 2008). Even though the effects of sugar on neurochemicals are mild, it can lead to a dependency or addiction over time.

In addition to the neurochemical reasons for sugar addiction, there is also an area in the brain that shows signs of sugar addiction. In a study where participants consumed sugar and brain activity was analyzed, it was found that the orbitofrontal cortex was active after sugar consumption. The orbitofrontal cortex is an area in the front of the brain where humans process rewards (Benton, 2009). This means that eating sugar is a rewarding activity, so we are likely to continue to eat sugar in order to feel reward and pleasure.

Other areas of the brain that were found active when sugar cravings struck were the caudate nucleus, hippocampus, and insula. These areas of the brain are some of the same areas in which drug cravings are activated. According to Pelchat, “it is as if, when craving, one has a sensory template of what has to be eaten to satisfy the craving.” In the case of sugar, people know that sugar has to be eaten in order to satisfy the craving.

Those at risk for sugar addiction include those with bulimia, binge eating disorder, obesity, are alcohol dependent, smokers, and those with chronic pain (Fortuna, 2010). This is because a sugar addiction is comparative to these disorders, and many times these disorders may occur congruently with sugar addictions.  “Healthy, normal weight individuals, by definition, do not suffer from food addiction; however, overweight and obese individuals could meet clinical criteria” (Pelchat, 2009). The reason for sugar addiction is not because sugar tastes good, but rather it is in the way it is consumed with alternating binging and restricting.

Environmental cues are capable sugar addiction triggers as well. Watching a commercial about candy, smelling cinnamon rolls come out of the oven, or simply being around sugar can cause someone to start eating it uncontrollably.  Eating sugar can also become a learned response by simply eating sugar when hungry, bored, or tired so that someone craves it whenever they feel this way. Overtime it will be a habit to simply reach out and eat sugar when these cues arise. This happens the same way with other drugs of addiction, too. A classic example shows that a motivated individual can pass through drug rehab perfectly. However, when he returns to his old environment and friends, he will find himself craving drugs again because of the environmental cues (Pelchat, 2009).

Sugar has only recently been thought of as something people can become addicted to. Therefore, the research that supports sugar addiction is rather new and is not as abundant as other research topics. While the studies performed on rats and humans point to the neurochemical and biological effects of sugar, many doctors and scientists in the community are still skeptical as to whether there is a clear connection between the human body and sugar addiction. Because this is a rather new research topic, it may take more time and more studies to convince people in the scientific community of the validity of sugar addiction. Through learning about the studies performed so far and seeing the affects of sugar on others, sugar can be a very real addiction.

Sugar addiction, or sugar dependence, is based off the three basic stages of bingeing, withdrawal, and craving. Sugar can cause the neurochemicals dopamine, tryptophan, and serotonin to increase. All of these are involved with pleasure, reward, and pain tolerance that can make sugar irresistible. These neurochemicals are also released with other drugs of addiction, which links sugar addiction to any other addiction. With more research and studies I am sure that sugar addiction can become an even more well-known addiction in the scientific and medical community.

References

Avena, N. (2008). Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neuroscience & Bio Behavioral Reviews, 32(1), 20–39.

Avena, N. (2009). Sugar and fat bingeing have notable differences in addictive-like behavior. Journal of Nutrition, 139(3), 623-628.

Benton, D. (2009). The plausibility of sugar addiction and its role in obesity and eating disorders. Clinical Nutrition, 29(3), 288-303.

Corsica, J. (March, 2010). Food addiction: true or false? Current Opinion in Gastroenterology, 26(2), 165-169.

Diagnostic and statistical manual of mental disorders: DSM-IV-TR. (4th ed.). (2000). Washington, DC: American Psychiatric Association.

Fortuna, J. L. (2010). Sweet Preference, Sugar Addiction and the Familial History of Alcohol Dependence: Shared Neural Pathways and Genes. Journal of Psychoactive Drugs, 42(2), 147-151.

Pelchat, M. (March, 2009). Food addiction in humans. The Journal of Nutrition. 139(3), 620-622.

Tuomisto, T. (March 1999). Psychological and physiological characteristics of sweet food “addiction.” International Journal of Eating Disorders, 25(2), 169-175.