Sugar has been in the spotlight for a while, it being the most likely culprit of the obesity epidemic of our time. As to how is that possible, many consider that it is because it leads to an addiction, with sugar acting as the sweet sweet drug driving our wants and needs. A new study 1 used 7 mini pigs as a proxy to study the effects of sugar in the brain. For that purpose the researchers imaged their brains every day for 12 days after feeding them 2 liters of a sugary liquid. What they found was that the pig’s reward system and the release of the “feel-good” neurotransmitters dopamine and opioids were stimulated similarly as drugs of abuse like cocaine, among others. CT scans of the pigs’ brains showed an overloading and desensitization of dopamine receptors already shortly after starting with the sugar feeding, which leads to the diminished pleasurable sensation of the sugary drink over time. This dampening of responses in the brain systems related to pleasure reminds of what happens in the brains of cocaine addicts. A real sugar addiction. The researchers were surprised that sugar could drive this strong effects in the brain after so little time, specially because if translatable to humans that would mean that many brain functions would be impaired practically on a daily basis and almost since birth. However. We must not forget that mini pigs, as similar as they could be to humans and useful as research models, they are still not human. Moreover, for the brain scans animals were sedated with ketamine, which is an opioid that could potentially influence dopaminergic receptors and confound results. In any case, despite the possible confounders in this study, the results align with more evidence pointing towards sugar as the drug of the century. And this silent killer is one to beware, for we all are in danger of a sugar addiction.
Winterdahl, M., Noer, O., Orlowski, D. et al. Sucrose intake lowers μ-opioid and dopamine D2/3 receptor availability in porcine brain. Sci Rep9, 16918 (2019). 10.1038/s41598-019-53430-9↩