Brain, Food, & Stress

I'm wrapping up my undergrad experience. It pains me to say so for some reasons and thrills me for others. It is only natural to complete things, enjoy the satisfaction of that, and look fondly on the journey that you've made. Life is full of these defined periods of time and defined areas of focus. I completely failed at keeping up with this blog while going to school. So the 6 of you that actually follow me, I apologize. I did succeed at my schooling though. I am graduating with honors and a degree in Applied Nutrition and a minor in Biology with a focus in Anatomy/Hematology.  The future is bright, as it always has been. I am moving to Beavercreek Ohio to live with two of my bestfriends and one of my heroes, Molly and Ty, and the captain- respectively. I will be doing a dietetic internship at Miami Valley Hospital and soon take a test to become a registered dietitian. I can't believe it is all happening finally.

The name of this post is brain, food and stress. Three things that I've been closely intertwined with lately. First the brain, i've had to stuff so much in mine if you saw me you'd see a body with a stuffed turkey head walking around(remember that friends when Monica did that?!). Not really but yes, I've learned so much and I'm excited to share it all. Food... well that's obvious- it's my passion. And, finally stress- I've been under a lot of it lately. So these things have been present with me or affected me lately... yet I want to write and explain a little bit about how they all play on one another... in everyone... not just Caitlin Rose.

I am going to do this in two posts, some of the science then some of the corresponding behaviors.

 Science and Background Stuff

You may be interested to know that the same neurotransmitters in the brain that are important for normal feeding and intake also participate in the "fight or flight" response when people are under stress. For those of you that care they are: serotonin, dopamine, acetylcholine and norepinephrine.

These neurotransmitters are made up of different building blocks. The amino acid tyrosine is made to build serotonin. Tryptophan(you know that turkey I had on my head a minute ago, that is where you get this guy) makes up dopamine and norepinephrine. Tons of vitamins and enzymes are also required to make up these chemical transmitters.

Serotonin

This neurotransmitter(NT) increases the appetite for carbohydrates (especially sweets). When the carbohydrate need is met the preference should switch to protien. In adequate amounts of serotonin may cause depression. This vagus nerve communicates by way of this NT to get messages from the brain to the GI tract. Excess serotonin causes slower stomach emptying(slower digestion), bloating, and constipation. A serotonin deficiency can be caused by abnormal excitation of "fight or flight" response. 

Acetylcholine

Acetylcholine can both excite and inhibit other mechanisms in the brain. It helps control emotional processing, learning, memory regulation and taste aversion. When cortisol(stress hormone) levels are high it stimulates and depresses the adrenal axis of the brain. This can decrease thyroid function. So keeping cortisol low can help to make sure proper functioning of this NT. Cortisol is increased with excess, excess carbs or poor regulation of blood sugar.

Norephinephrine

This NT can excite or inhibit as well. It indirectly integrates a stress response and can cause decreased desire for food intake when physiologic stress is present. It stimulates the adrenal system to breakdown and use energy. It can also slow down other body functions during times of high stress.

Dopamine

The happy NT. It can be increased with food makes people happy. It is the reward NT. It works to also reinforce learning in the brain. So when you eat the brain learns this is good and it makes us happy.

Eating is Some Complex Business

The body and brains regulation of eating is a very complex process. Eating is necessary for survival, we all know that. So is sex for that matter(the survival of a species)... and it involves a lot of dopamine too, but I digress. The central nervous system has a lot of redundancy in order to help ensure eating and survival.

Eating is often regulated by emotions, time of day and surroundings. The hypothalamus is the major regulator of this all. Long-term regulation of feeding(eating) is related to maintaining adequate fat stores for survival(thank you evolution). Leptin is secreted in the hypothalamus, other places in the brain, the placenta, skeletal muscle and the gi tract. It has immune function too, but that isn't our main focus here. Leptin and insulin act on the hypthalamus and cause a slowing of building pathways, building protiens, muscle etc. Ingestion of food generates increases in leptin. When there is a period of no eating(or fasting), the leptin levels fall. It comes from fat tissue and is a hormone(which is just a fancy way of saying it helps tell somewhere else in the body to change what it is doing).

High carb meals and low fat meals produce higher leptin levels. More leptin means more energy storing. More carbs, more signals to store store store! That doesn't mean you should stop eating carbs. But they should be a part of an overall balanced diet.

More later on how this all comes together in changed behaviors... for now this is just some of the basic science that goes into it.

Thanks for reading. Stay tuned!