It’s not that you couldn’t resist that chocolate bar, bag of crisps or portion of chips, but your brain couldn’t. A new study suggests that your brain can learn to love sweet and fatty snacks as it could be “rewired” by routinely giving it a high-fat, high-sugar pudding; the authors believe.
To investigate the brain’s role in the craving for high-fat, high-sugar foods, an international team of researchers led by the Cologne-based Max Planck Institute for Metabolism Research gave normal-weight persons a rich pudding twice daily for eight weeks in addition to their regular diet and examined their brain activity both before and during the study.
A control group was given pudding with the same calories but less fat and sugar.
“Our tendency to eat high-fat and high-sugar foods, the so-called Western diet, could be innate or develop as a result of being overweight. But we think that the brain learns this preference,” said Sharmili Edwin Thanarajah, a postdoctoral research fellow at the institute and lead author of the study, laying out the researchers’ central hypothesis.
They found that brain activity significantly increased in the group that ate the high-fat, high-sugar pudding, which mainly activated the dopaminergic (i.e., involving dopamine) system, the region in the brain responsible for motivation and reward.
Dopamine is the “feel-good” hormone and is essential from an evolutionary standpoint. The brain releases large amounts of it when we do things required to survive and reproduce, such as eat and have sex.
“Our measurements of brain activity showed that the brain rewires itself when we consume chips and the like. It subconsciously learns to prefer rewarding food,” explains study leader Marc Tittgemeyer, a professor and head of the translational neurocircuitry group at the German institute.
The combination of fat and sugar is incredibly “rewarding.” The researchers note in their study that “many modern processed foods are high in energy density and frequently contain both fat and sugar, which interact to potentiate reinforcement beyond the energetic value.”
During the study, the test persons didn’t gain more weight than those in the control group, and their blood levels, such as blood sugar and cholesterol, didn’t change either. However, the researchers assume that their preference for fatty and sugary foods will continue beyond the end of the study.
“New connections are made in the brain, and they don’t break up very fast,” said Tittgemeyer. “After all, the whole point of learning is that once you learn something, you don’t forget it so quickly.”
The researchers’ findings were published in the U.S.-based scientific journal Cell Metabolism. However, they caution that the study supports, but doesn’t prove, their hypothesis, partly because of the small number of test persons – 57. And the results, they add, could be different with people who are overweight, with an extra snack or study duration.
