Blog Post 1: Craving Sweets

Craving Sweets

Have you ever seen a Cosco cheesecake advertisement on television and felt your mouth water? Imagine that feeling, but with the same to-die-for sensation as the urge for drugs or cigarettes. I recently read “Physical Craving and Food Addiction”, a scientific review paper written by Mark Cheren, Mary Foushi, Ester Helga Gudmundsdotter, Colleen Hillock, Marty Lerner, Michael Prager, Mary Rice, Louisa Walsh, and Philip Werdell. According to the research recorded in this journal, binge eating and consuming sugary substances  may have the same addicting effects on the brain as drugs and alcohol do.

In measuring addictions, Wilson defines physical craving as a sensation much different than simply hunger because the person feels an increased need for food having just eaten, which contradicts the expected feeling of being full after eating a meal. Hoebel expands on this definition by organizing it into three characteristics: (1) An animal used to be rewarded for a certain behavior but still continues that behavior even though there is no longer any reward; (2) After consuming a substance over time, the animal’s appetite and desire for it increases; (3) When a substance is taken away from that animal for a period of time, the animal will take more of the substance than before the period of withdrawal.

During animal testing, Hoebel observed for these three traits of physical craving and found that the laboratory animals given sugar versus those given alcohol and narcotics  shared the same results: (1) The animals continued behaving in ways that previously rewarded them with the substance, even though that reward no longer existed; (2) Over time, the animals needed increasing amounts of the substance to feel satisfied; (3) When the substance was returned to the animals after a period of deprivation, the animals consumed more than they had before deprivation. Furthermore, animals continued craving sugar in the face of punishment, which strengthens the conclusion that sugar can cause physical cravings that may affect brain pathways. Ahmed repeated these laboratory experiments with various substances, and found that even the rats addicted to cocaine preferred sugar and sweetness over drugs.

Researchers looking at human brain imaging observed that dopamine areas in the brain changed due to food binging, which causes an increased appetite and need for the food. In fact, Wang discovered that pictures of food trigger the dopamine areas of food bingers to light up. This reflects the same brain response as when drug addicts see drugs, or even think about drugs.

From a biological perspective, craving occurs when the body produces opioids, which are chemically similar to those found in addictive narcotics such as heroin and morphine. Because opioids are produced through the pattern of sugar/fat  consumption, deprivation, and more sugar/fat consumption, binge eating can create an addiction to certain foods because it mirrors this pattern. As a result, the opioids produced by the body from binge consumption of sugar and fat may affect the brain’s dopamine receptor areas in the same way that morphine and heroin opioids do.

To test the idea that opioids cause physical craving for sugar, Drewnowski experimented with naloxone, an opioid blocker that allows drug and alcohol addicts to feel no craving for their substance. In the experiment, two groups of students were given sweets and their eating patterns were observed. Then one group of students were given naloxone. The group of students who were not given naloxone continued eating the offered sweets, whereas the group given naloxone showed no interest in eating sweets all of a sudden. This shows a relationship between sugar and opioids because the naloxone was able to block physical craving for sweets, just as it has past been proven to block craving for heroin and morphine.

Aside from dopamine, another chemical released by the body that causes addictions is serotonin. Unlike dopamine, which causes addiction by making people feel happy, serotonin is a pain reducing chemical. Processed foods can trigger the body to release serotonin because the insulin used in digestion lowers blood sugar levels. Meanwhile the amino acid tryptophan can travel to the brain, creating a reaction with serotonin.

Overall, it looks as though sugar is just as addicting as other drugs from both an internal level with the opioids, but also on an external level with the animal observations that prove sugar may create physical craving. By looking at the human brain scans of the dopamine area, people addicted to sugar have the same effects as those addicted to other drugs. The reason behind this is that our body creates opioids if we binge eat sugar and replicate the pattern of consuming, depriving, and then consuming again.

Now that I understand the biological effects of fat and sugar on the brain, I plan to experiment with different recipes of brownies and altering the recipe to see which one tastes best to people.

Bibliography

Cheren, Mark, Mary Foushi, Ester H. Gudmundsdotter, Colleen Hillock, Marty Lerner, Michael Prager, Mary Rice, Louisa Walsh, and Philip Werdell. "Physical Craving and Food Addiction." Physical Craving and Food Addiction (2009): n. pag. The Food Addiction Institute PO Box 50126, Sarasota, FL 34232. Web. 22 Jan. 2015. <http://foodaddictioninstitute.org/FAI-DOCS/Physical-Craving-and-Food-Addiction.pdf>.