Obesity is a growing problem that transcends boarders across the world. There’s the ongoing argument about the battle of free will and people’s genetic disposition towards being obese. Many people argue that being obese is a personal choice and that it’s the person’s inability to “put down the fork” and exercise properly that leads to them being obese. However, what if I told you that new evidence is pointing towards obesity being a brain disorder? What if I told you it wasn’t completely up to free will? Would you think I’m crazy? Let me explain.
It is believed that people are predisposed to having brain defects inhibiting their ability to control their choices regarding eating and overeating. This inability is caused by neurodegeneration in specific areas of their brain which control their executive reasoning, reward system, and overall cognition. Early stages of life have a great effect on our brain development as we progress through life. Our diets have the ability to lead towards proper development or improper development.
High fat diets lead to the disruption of our blood brain barrier which controls the exchanges between our blood stream and our brain tissue. The blood brain barrier is highly specific because the cells which make up the lining of our capillaries are highly compacted (aka have tight gap junctions). These “epithelial cells” have tight gap junctions which are surrounded by the end foot of astrocyte cells (clean-up/ helper cells of the brain). The astrocytes wrap around the gap junctions of epithelial cells in order to add another level of specificity to the exchanging of molecules and ions with the brain tissue. High fat diets disrupt this highly specific barrier by down-regulating mRNA which encodes very important proteins. These proteins hold epithelial cells tightly together producing the tight gap junctions which are vital to a properly functioning blood brain barrier. When these gap junctions are loosened there is the ability for dangerous molecules to be exchanged into the brain causing damage. The damage in the brain is usually due to oxidative stress leading to neurodegeneration, very similar to what we’ve seen in other neurodegenerative diseases before.
High fat diets are high in triglycerides which also disrupt the blood brain barrier. Triglycerides inhibit leptin and insulin receptors on the blood brain barrier that allow for proper transport of these molecules into the brain. These molecules (leptin and insulin) lead to the brain’s response telling us to stop eating because we’re full. When triglycerides inhibit the transporters for these molecules, we’re unable to properly transport them into the necessary regions of the brain thus we continue to eat. This is how leptin and insulin resistance is created in the body, commonly found in obese individuals.
Obese individuals brains exhibit volume deficits in their hippocampus and hypothalamus (regions associated with memory and executive functions [decision making]). These deficits are due to improper exchange with the blood brain barrier due to high fat content in their diets currently, when they were children, or even when they were in the womb. These findings put a lot of responsibility on the parents to provide adequate nutrition for their children early in life in order to lead to proper brain development.
I used to believe completely that obesity was a choice. After reading more into research regarding brain defects causing inability to feel “full”, to properly use our executive functions, and have our memory center altered, I truly believe obesity is an actual brain disorder. Depending on how your mother’s diet was during pregnancy and how your diet growing up was, some people are predisposed to be obese. Will power has a lot stacked up against it for some people whose brains are telling them to keep eating even though they shouldn’t. It’s a vicious cycle that is better to be avoided than broken.
Until Next Time,
Sebastian
Obesity: Not (Completely) Our Fault
