Brain on Sugar
Understanding sugar's role in addiction and weight-gain.
The left side is your brain on sugar; the right side is your brain on drugs. Notice the similarities?
This striking comparison helps us to see how sugar is far more influential on the brain and body than you might think.
When we eat things like flour and sugar, a massive flood of dopamine enters the brain; the same way it does when one ingests drugs like cocaine and heroine. The PET scans above indicate a lack of dopamine receptor activity which, in a healthy body, would register in red.
Dopamine receptors in the brain are responsible for how we experience pleasure. When we ingest these substances, the dopamine flood that ensues over-stimulates the brain which causes a rush of pleasure but also forces the brain to compensate by down-regulating, or thinning-out the active dopamine receptor sites.
This is the basis for cravings and addiction, and a strong contributor to certain neurotransmitter dysfunction and imbalance. When pleasure centers of the brain are greatly reduced or unresponsive, symptoms like depression and anxiety are a logical result. In a state of down-regulation, the body naturally compensates by seeking out sudden bursts of potent stimulation in the form of intense cravings for sugar, flour or other addictive substances. Because the pleasure centers are already reduced or unresponsive when it receives another intense spike, the active receptors are then overstimulated and further thinned moving into a deeper state of down-regulation. This viscous cycle leads to the long-term deficiency of neurotransmitters necessary for healthy mental and mood function.
Take a look at this second comparison. The normal brain shows active dopamine receptors in red. The cocaine and obesity-affected brains are shown in a state of down-regulation induced by ingested substances, and thus show an absence of red (dopamine) activity. When a person struggling with weight-gain consumes highly processed foods, the net result is a consistent reduction in dopamine receptor activity. This leads to a diminished sense of well-being and a compensation in the form of intense cravings signaling the body to consume more highly processed foods for short-term satisfaction.
Substances like flour and sugar don’t affect all individuals equally, but the same dynamic present in drug addiction is present in the struggle with obesity. In every body, insulin levels are elevated by processed foods containing flour and refined sugar. In a healthy body, Leptin, a hormone secreted by adipose fat cells, signals the brain that you are "full and ready to get active". It is commonly known as the "satiety hormone" and helps to regulate energy balance by inhibiting hunger. High levels of insulin (caused by ingesting high glycemic foods like refined flour and sugar) disrupts the feedback loop between Leptin and the brain and, therefore, the brain doesn't receive the message that the body is full.
When insulin levels are low and flour and sugar are eliminated (or at least minimized), the body's communication system can function correctly. Metabolism can resume healthy function, in part because Leptin is received by the brain and not blocked by too much insulin, therefore cravings and false hunger cues disappear.
The good news is: your body is designed to heal. When you stop ingesting these substances that flood the brain, a healthy range of dopamine receptors will return laying the foundation for health and thriving.