Cobbers on the Brain

Story Time:

I have never experienced a concussion, nor have I ever seen someone I’m close to get a concussion. This statement would’ve been true a year ago, but I can no longer say this is the case. This past March, one of my best friends got a concussion and it was an event I will never forget. I was at this friend’s house, hanging out with her roommates and mine while we waited for her to get off of work. She had been snapchatting us throughout the evening, telling us about the drama going down at work. She had told us that she got hit in the head amidst the drama, but she wasn’t feeling anything more than a headache. She arrived at her apartment 20 minutes later, greeting us but excusing herself to her room to lay down. Almost two hours later, my friend came out of her room, tears streaming down her face as she held a hand to her head. She looked at my roommate and I and asked, “when did you guys get here?” Immediately, our concern skyrocketed. We replied that we had been there since nine o’clock, and she had greeted us when she came in the door. She then proceeded to ask, “how did I get home?” My roommate and I looked at each other, mutually deciding that we needed to take our friend to the emergency room. We continued to ask our confused friend questions about what day it was, what she remembered, and how she was feeling as we prepared her to go. We helped her get her coat on and grabbed her ID before taking her down to the car. I gave my friend a blanket that she could use to block out the lights, and we were on our way to the emergency room.

Upon arrival to the emergency room, I knew my friend’s condition had worsened. My friend was squinting at the light as we stepped out of the car. She was very unsteady as we walked to the front doors of the emergency room—I was essentially holding her up, at this point. At this time, COVID was still a severe problem, so they were not allowing people other than the patient into the ER. However, the person at the COVID checkpoint saw the pair of us and said nothing as I walked my friend to registration. I told my friend to close her eyes as I checked her in, as she couldn’t even remember her birth date. I went to the front desk and told her who my friend was, what had happened, and gave her my friend’s photo ID. A nurse came out with a wheelchair just a few minutes later, and the two of us got my friend seated in the wheelchair. The nurse took my friend to the back, while I waited in my car in the parking lot. My roommate and I were waiting for our friend at the emergency room until 3:00 am.

Post-Concussion Thoughts:

Whenever I thought about concussions prior to the incident with my friend, I imagined how much it would hurt to be hit that hard in the head, but I never thought about the actual injury itself. I never thought about the memory loss, the confusion, the photophobia, or the  loss of balance one may experience after the event. It wasn’t until I witnessed it with my friend that I began to think about all of the conditions associated with concussion. Figure 2 shows a more complete list of concussion symptoms, but I will focus on only a few.

I also have never thought about the biological causes behind these conditions. The migraines, light sensitivity, and sound sensitivity can all be attributed to the ion flux that occurs following a concussion.[1] Ion flux is the movement of ions into and out of the cell. This flux occurs because a concussion makes little holes in the plasma membrane, which allows calcium and sodium to move into the cell and potassium to move out of the cell.¹ A good model for this idea is the sharing of a twin bed. If one person is in the bed, and another joins, the original person is likely to leave (unless they fight for it, but let’s imagine this occurs in a perfect utopian society). This movement of ions can cause depolarization of the membrane, leading to excess release of glutamate.¹ The impaired cognition, slowed reaction times, and slowed processing often seen post-TBI are attributed to impaired neurotransmission and axonal dysfunction.¹ Impaired neurotransmission is an imbalance in the release of excitatory and inhibitory neurotransmitters. There are more excitatory neurotransmitters (action-inducing chemicals) binding to receptors than inhibitory neurotransmitters (action-inhibiting chemicals).¹ The axonal injury is the stretching of the axons of neurons.¹ Like a hair tie that you’ve used one-too many times, the axon stretches out and weakens as a result of the trauma to the brain. All of these things were going on in my friend’s brain, lasting months after her injury. You don’t really think about any of these severe effects from a concussion until you are a witness to it. I will remember this event forever, and I am glad that I am able to connect my friend’s symptoms to biological events going on within her brain.

[1] https://moodle.cord.edu/pluginfile.php/1052900/mod_resource/content/3/2014%20The_New_Neurometabolic_Cascade_of_Concussion.3.pdf

Image 1

Image 2

The obesity rate within America during 2017-2018 sat at a staggering 42.4%. If that wasn’t bad enough, 73.6% of Americans are now considered to be overweight. Look at the chart below, obesity rates within the US have increased exponentially since the 60’s. Several drastic changes occurred during the 80’s within American culture/society that impacted obesity rates, leading to the exceptionally high rates of obesity.

Figure 1

Obesity is associated with many negative health conditions. These conditions cost America anywhere between 147 and 210 billion dollars annually. Will our societal eating habits become so greatly problematic to the point of Wall-E? As a kid I thought the movie was funny, the portrayal of the overweight people seemed to be amusing and unrealistic since there appeared to be a complete lack of healthy humans. However, if Americans continues this trend towards increased obesity, we could end up looking similar to those pictured in this fictional movie. Would I still find it funny, probably not.

Picture credits; Wall-E

One of the changes mentioned earlier that took place in the 80’s relates to the change in meal composition. As a society we are moving away from healthier meals in favor of high fat diets. We talked at length about this in class, there are several negative consequences of eating a high fat diet. You can find that information on this document if you would like to look more into it. As an example of how we’ve changed out consumption of different foods, lets look at a couple of examples. Consumption of vegetable oil within Americans diets has DRASTICALLY increased over time. 400 additional calories are consumed daily due to this one ingredient alone. Unfortunately that is not the only food “category” that has changed. Look below to see examples of three food categories and how their average (daily) caloric intake has changed over time.

Figure 2, 3, and 4

Here is a list of the top calorie sources within the US diet

1. Grain-based desserts (like cakes, cookies, and donuts)

2. Breads made with yeast

3. Chicken and chicken dishes

4. Soda and sports drinks

5. Pizza

6. Alcoholic beverages

7. Pasta and pasta dishes

8. Mexican dishes

9. Beef and beef dishes

10. Dairy desserts (like ice cream and cheesecake)

In case you hadn’t noticed, none of these are overly healthy options and are all very high in fat, leading back to the article relating to high fat diets and how unhealthy that is for us.

The American diet in terms of daily calories has changed over time. Today Americans consume more than 3,600 calories every day which is a 24% increase from 1961 when Americans only consumed 2,880 calories daily. The chart below shows how the US food chain has ballooned over time in order to meet the demands of the consumers. The chart shows slightly different estimates of daily caloric intake, estimates that vary per source, but it shows the shift from 2,880 to 3,600 calories. Sources seem to have conflicting estimates, but almost all seem to agree that daily caloric intake has risen by at least 20%.

Figure 5

What changes have lead Americans to become so obese, especially the large spike in obesity during the 80’s? Well the simple answer includes several things: a change in the composition of meals (for example more saturated fat and vegetable oil), source of food (fast food over home cooking), and lifestyle changes (less exercise and more loungin around watchin the Vikings lose).

In terms of a changing food source, the graph below does a good job showing where families have gotten their food from over the years. Families used to eat at home, now fast food and restaurants compose a much larger percentage of weekly meals.

Unfortunately obesity in America is not only a problem of consumption, it is also a problem of physical exertion. What do I mean by this? Well, most Americans fail to meet the US governments minimum daily recommended exercise. That recommendation includes 75 minutes of vigorous cardiovascular exercise a week as well as muscle strengthening twice a week. Sadly only 23% of Americans achieve this minimal standard. Time is spent doing other things, for example watching television.

Figure 6

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With Americans having a higher caloric intake and a decrease in exercise it is not shocking to see a drastic rise in obesity. Lets all get out of our chairs, eat a little better, and work as a society to better our health. If we don’t and our diets continue to contain a high ratio of fat, we might get to a point where our body becomes resistant to both insulin and leptin. This scenario would lead to a detrimental feedback loop that would benefit no one, leading to even higher rates of obesity with little hope for individual health and well being.

Here’s a link to a video of me explaining my topic if you’d rather listen to my voice instead of reading: https://drive.google.com/file/d/1W9P1wZxyiVZsQILe2YTxtd4Sm4rKFIo-/view?usp=sharing

 

Centers for Disease Control and Prevention. (2021, September 30). Adult obesity facts. Centers for Disease Control and Prevention. Retrieved November 16, 2021, from https://www.cdc.gov/obesity/data/adult.html.

Centers for Disease Control and Prevention. (2021, September 10). FastStats – overweight prevalence. Centers for Disease Control and Prevention. Retrieved November 16, 2021, from https://www.cdc.gov/nchs/fastats/obesity-overweight.htm.

Schuler, L. (2021, February 12). The real reason Americans are so fat. Men’s Health. Retrieved November 16, 2021, from https://www.menshealth.com/weight-loss/a19536794/reasons-americans-are-fat/.

” why the world is overweight? the 1980’s and its contribution to our health now! Size Fantastic – Sustainable Weight Control – Healthy Weight Control and Weight Loss. (n.d.). Retrieved November 16, 2021, from https://sizefantastic.com.au/weight-loss-tips/why-the-world-is-overweight-the-1980s-and-its-contribution-to-our-health-now/.

 

 

 

 

Am I hungry or not? 

Leptin is a hormone that decreases your appetite while ghrelin increases it. These hormones aid in determining an individuals weight. However, when there is a malfunction in the signaling pathways an individual can experience weight gain/loss.

Drawing by Hannah Paulson

For people with eating disorders, the decision of what to eat is a complicated snarl of anxiety and guilt. And it’s not much less complicated for people without eating disorders. Our appetites, for what and how much we eat, are regulated by a complex array of hormones, hunger, and desire. When these systems are working properly, everything is great. We eat what we need and want, more or less. Our weight is appropriate for our genes and body type. Our diet is varied and tasty. 

Leptin

As in any complex system, however, things can go wrong. Research has shown us that eating disorder sufferers have problems regulating feelings of hunger and satiety that can perpetuate and perhaps even contribute to the onset of illness. Several key hormones and brain processes have been identified that may be malfunctioning in people with eating disorders. Leptin and ghrelin, discussed below, also interact with a variety of other hunger and satiety signals to help keep our bodies fueled properly. 

Leptin is a hormone produced by fat cells that signals satiety. Researchers at Rockefeller University discovered the leptin gene almost 20 years ago, and researchers soon showed that leptin is one of the many reasons why diets don’t work. As body fat stores go down, so do leptin levels. Lower leptin levels mean that it takes longer to feel full after eating, which serves to bring the body back to its original weight. 

Since leptin is a key component of appetite and body weight regulation, scientists suspected that leptin might be involved in eating disorders. Researchers measured leptin levels in 67 women with eating disorders, compared to 25 healthy women. As expected, leptin levels were significantly elevated in the women with binge eating disorder compared to healthy women, but they were significantly lowered in women with anorexia or bulimia. 

Normally, high levels of leptin are associated with lower levels of endocannabinoids, brain chemicals that, among other things, regulate appetite. Low levels of endocannabinoids should make a person feel less hungry. This isn’t the case in people with binge eating disorder; their elevated leptin levels are actually associated with high levels of endocannabinoids, which could help promote further binge eating.

In bulimia, leptin levels appeared somewhat lower than expected, and lower leptin levels were associated with more frequent binge eating. A later study found that low leptin levels in women with bulimia were also associated with more chronic, severe illness. 

When researchers compared leptin levels in women with anorexia to women who had low weights for other reasons, they found that leptin was significantly higher in the women with anorexia. This blunted leptin response could help explain why people with anorexia are hyperactive and can continue starving themselves for long periods of time. They are hungry, yes, but not as hungry as they should be.

Ghrelin

Ghrelin is secreted by the stomach and acts opposite to leptin. Whereas high levels of leptin help trigger satiety, high levels of ghrelin help trigger hunger. Ghrelin levels typically rise before a meal and decrease afterwards. The hormone is thought to work in part by helping to stimulate the brain’s reward system to encourage eating. 

Scientists found that, in women with binge eating disorder, ghrelin levels were lower than in women with similar BMIs. Other researchers have found similar results indicating that decisions about eating aren’t dictated just by hunger and fullness, but by other emotions as well. 

When researchers measured ghrelin in women with bulimia, they found that levels of this hormone didn’t decrease as much as it did in control women. Since women with bulimia don’t feel as full after a meal, they may be more likely to binge or overeat. In anorexia, ghrelin levels are elevated, as expected with someone who is starving. During the refeeding process, however, ghrelin levels drop dramatically, which could help explain why many people with anorexia struggle to put on weight because their hunger signals aren’t working properly.