The Science Behind Bagels

By Susan Wang '22

It is a sleepy two p.m., when a thought of a baked bagel refreshes you. Your memory of its pleasant taste haunts you, making you hungry again only an hour after lunch. What goes wrong?

This intense desire of consuming refined carbohydrates heavily depends upon a neurotransmitter called dopamine. During the digestion of carbohydrates, neurons become excited due to the release insulin and send signals to the Ventral Tegmental Area, often abbreviated to VTA. The VTA is an area in the midbrain that is highly populated by dopaminergic cells. Once the cells in the VTA are activated, they send the stimulus to cortex, eventually bringing you positive feedback (cited from Wang, Gene-Jack, et al). In actuality, however, being pleased from eating carbohydrates is a trick which your brain uses to reward itself; this trick has been proved effective throughout human history, especially during famines, because it encourages you to eat food that provides enough energy for you to survive (cited from Andrews, B. Zane).

Nonetheless, dopamine alone does not tell the complete story of your desire for refined carbohydrates. When these carbohydrates are fully digested, you experience a series of negative feelings such as anxiety, due to the release of Corticotropin Releasing Hormone--CRH. In comparison with dopamine, CRH is a hormone that functions in a totally different way. The former is related with reward systems, while the latter regulates stress responses. Studies show that one’s brain expresses large amounts of CRH during “withdrawal period”: when carbohydrates are withdrawn, your brain releases five times more CRH than usual (cited from Mervis, Jeffrey and Malakoff, David).

In brief, perhaps next time when you enjoy a bite of your nook bagel, you will remember that what makes it so irresistible isn’t just the taste or the urge to get in a quick meal between physics and history, but instead the surge of dopamine and CRH.

Works cited

Wang, Gene-Jack, et al. “Addiction: Beyond Dopamine Reward Circuitry.” PNAS, National Academy of Sciences, 13 Sept. 2011, www.pnas.org/content/108/37/15037

Andrews, B. Zane “Why Calories Taste Delicious: Eating and the Brain.” Scientific American, 30 Sept. 2008, www.scientificamerican.com/article/why-calories-are-delicious/.

Mervis, Jeffrey, and Malakoff, David. “Chocolate Cake: The New Heroin?” Science | AAAS, American Association for the Advancement of Science, 10 Dec. 2017,