BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: hormones

Can Eating Late Increase the Obesity Risk in Humans?

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On October 20, 2022

In Student Post

Are you frustrated that, despite your healthy diet, you constantly feel like you are lacking energy, gaining weight, frequently hungry, and fatigued? Did you know that adjusting the time you consume meals could resolve this? Let me enlighten you on why you might be facing these symptoms!

A recent study  by Brigham’s women’s hospital orchestrated experiments to answer the following question “Does the time that we eat matter when everything else is kept consistent?”.  In the experiment, 16 patients with a BMI (body mass index) that indicated they were overweight, were examined closely. The 16 patients were on strict schedules so that their behavioral and environmental factors wouldn’t disrupt their results. They all had the same amount of sleep, the same diets, the same amount of physical activity, and the same wake up time. The only thing manipulated was the times each of them ate their meals. Each patient recorded the times they felt an increase in appetite, had their body temperature and energy levels measured and gave blood samples. The conductors of this experiment performed biopsies  of adipose tissue from the patients, to evaluate how their eating times affected how the body stores fat. 

The test results showed that the participants that were on a later eating schedule had a decrease in a hormone called leptin, which  is a hormone that regulates your appetite and energy level. The patients with a later eating scheduled were caused to feel more hungry than the group that consumed food earlier due to their body’s decrease in leptin. Eating later also had an effect on Ghrelin which is a hormone that increases your appetite.

The experiment discovered evidence that the group eating later was more at risk of obesity.  The adipose tissue gene expression revealed the pathways involved with lipid metabolism, receptor tyrosine kinases, and autophagy was altered in a way that decreased lipolysis and increased adipogenesis. Lipolysis is the process  of breaking down lipids. In our biology class, we learned how hydrolysis is the process where water is added to a molecule, which results in the molecule breaking into smaller molecules. In lipolysis, hydrolysis breaks down triacylglycerols into glycerol and free fatty acids. In biology class, we learned that lipids provide us with mass amounts of energy when they are broken down and if they aren’t being properly broken down in our body it can lead to damage in our cells and tissues. We also learned in biology class that autophagy allows your body to break down and reuse old cell parts so  that our bodies won’t work as efficiently. 

Lypolosis

Overall, the time of our eating has many effects on our appetite, body temperature, weight fluctuation, number of calories we burn, energy level, and risk of obesity, and can even cause  molecular changes in our fat tissue. In the future, Brigham and Women’s Hospital, hope to perform more related experiments to discover further information about this topic and specifically the relationship between meal time and bedtime on energy balance.

I have always tried to be the healthiest version of myself, which will make me feel like my best self. I remember telling my brother that I was feeling sick because I ate really late at night and he laughed at me and said I was being dramatic. It is really interesting to learn the science behind eating late at night and how it can affect how you look and feel. I especially liked gaining a better understanding of this topic because now I know the factors that cause my body to not feel as great when I eat later than usual! 

Menstruation Does Not Affect Cognitive Performance…Period.

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On January 3, 2018

In Student Post

Mood swings, abdominal pain, nausea, acne, and bloating.  Do any of these sound familiar?  These are all some of the most common effects of menstruation and, until recently, a drop in cognitive function was widely accepted as another one.

Despite what old assumptions might have been, new scientific research is transforming the way that we look at the menstrual cycle.  According to a study led by Professor Brigitte Leeners, menstruation does not actually negatively affect your cognitive functions.  It is common for people to believe that hormones that are released during the cycle have a significant effect on cognition, but Leeners learned that estrogen, progesterone, and testosterone do not actually consistently inhibit cognitive performance.

Leeds measured cognitive ability at four different points during the menstrual cycles of 68 different women.  The participants were tested on their abilities through tests that specifically measured their cognitive bias, memory, and attention.  The test spanned the courses of two consecutive menstrual cycles.

As one can expect from an experiment, there were outliers, so some women experienced cognitive changes as a result of their periods.  According to Leeds, however, “Although there might be individual exceptions, women’s cognitive performance is in general not disturbed by hormonal changes occurring with the menstrual cycle.” So, even though certain women were affected by their cycle, the overwhelming trend showed that, typically, women are able to perform just as well whilst menstruating as they would if they were off of their cycle.

So, your period affects a lot of things.  It can cause discomfort, fatigue, gas, vomiting, and more.  But one thing it cannot do is prevent you from taking your next biology test or attending your 8 AM classes.  Oh well.

Massages Actually Relieve Stress!

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On December 3, 2012

In Student Post

flickr
Photo by FoundryParkInn

When people say that they are taking a spa day, people are skeptical. But, according to a new study massages lower levels of stress hormones in the body. According to this study, people who have regular massages have substantially lower levels of cortisol and higher levels of white blood cells compared to people who do not get massages regularly.

Dr. Mark Hyman Rapaport, the chairman of psychiatry and behavioral neurosciences at Cedars-Sinai Medical Center, said, ” […] the findings are very intriguing and exciting, and I’m a skeptic!”

The study consisted of 53 adults. 29 of these adults were given a 45 minute Swedish massage once or twice a week for 5 weeks. The other 24 adults in the study were given light touch massages for the same time period. After the 5 week trial, the adults who had received the Swedish massages had significantly lower levels of cortisol, significantly higher levels of oxytocin, and slightly higher levels of white blood cells than those who had received the light touch massages.

The Mayo Clinic points out that regular massages can help to alleviate stiffness, pain, anxiety, depression, and maintain a regular blood pressure. The health benefits of massages are endless!

For more information on the health benefits of massages go to: http://stress.about.com/od/stresshealth/a/cortisol.htm

 

Pull-Ups, Biology, and Our Sexist Society

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On November 26, 2012

In Student Post

Men and women are different, right? Guys have more testosterone, which leads to greater muscle mass, facial hair, deeper voice, and greater height. Women have more estrogen, which leads to the development of characteristics like wider hips, and breast development. Having less testosterone means it is harder to gain strength, but not impossible. Anyone can, with the proper training regimen  increase their strength, regardless of sex. This, however, goes against what New York Times writer Tara Parker-Pope writes in her article Why Women Can’t Do Pull-Ups. In it, she cites a study in which

 Three days a week for three months, the women focused on exercises that would strengthen the biceps and the latissimus dorsi — the large back muscle that is activated during the exercise. They lifted weights and used an incline to practice a modified pull-up, raising themselves up to a bar, over and over, in hopes of strengthening the muscles they would use to perform the real thing. They also focused on aerobic training to lower body fat.

According to the study, only four of the seventeen women were able to do one pull-up at the end of the study. I, along with several hundreds of people who have posted angry comments on this article, have several issues with this study, and with the title of the article.

First, they focused on exercises that would strengthen the biceps and latissimus dorsi. My question is, what about the deltoids and trapezius muscles, and the core muscles in the abdomen, and grip strength? All of these come into play to some extent in a pull-up.

Second, I know from personal experience that using an incline to work your way up to pull-ups, often called a supine row, does not work.  I tried this for months and still could not do a pull-up. What did work was jumping over the bar and lower myself slowly (this is called negatives), and using resistance bands to hold whatever weight I could not support while doing a full pull-up. Now, I can do pull-ups. And, when you really think about it, a supine row uses the same muscles but the movement is in no way similar, so it doesn’t make sense to see it as a “toned-down” pull-up for beginners.

Taken by Amber Karnes
http://www.flickr.com/photos/ambernussbaum/4472515271/
2010 CrossFit Games; Women did pull-ups with a 14 lb vest.

Third, how in shape were these women? This was not made clear in the article, and obviously, even after six months to a year, a morbidly obese woman may not be able to do a pull-up.  I think the issue with the study and the article comes down to two things: bad journalism and bad science.  When a 17 year old AP Biology student is able to poke a bunch of holes in your argument and find a bunch of flaws in your experimental procedure, the competence of the individuals involved comes into serious question.

So, readers, can YOU do a pull-up? Do you know any females that can do pull-ups? And, if you were to run the experiment, what would you do differently?

Comment!

Original Article:

http://well.blogs.nytimes.com/2012/10/25/why-women-cant-do-pull-ups/

 

Additional Information:

http://en.wikipedia.org/wiki/Supine_row

http://en.wikipedia.org/wiki/Pull-up_(exercise)#Muscles_used

 

Photo: http://www.flickr.com/photos/ambernussbaum/4472515271/

Stress is Good for you?

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On October 1, 2012

In Student Post

Does this look familiar?

High school is stressful. Students are forced to balance heavy loads of school work on top of family obligations and time-consuming extracurricular activities. We all know a little bit of stress is healthy, providing just enough motivation to give you a kick in the butt, but not enough to make you want to pull your hair out. However, when finals time rolls around and you’re ready to cry because you’re so overburdened, then stress becomes a problem. When you’re stressed, glucocorticoids, or stress hormones increase the level of cortisol in your body, prepping it to take on the physical demands of stress. (In terms of evolution, being under stress is being chased by a lion that thinks you’re dinner, not taking the SAT tomorrow). Science has always told us that stress is bad for us; high levels of cortisol are linked to depression and high levels of cortisol over prolonged periods of time actually impair our ability to cope with stress. Just reading about this is stressful, right? But what if I told you that stress might actually be good for you, at least in one respect. A new study conducted by Ranjish Rao and published in Biological Psychiatry shows that high glucocorticoid levels could potentially help reduce the development of PTSD, or Post-Traumatic Stress Disorder.

 

No, I’m not Crazy. Stress Really Can Be Good for You

PTSD is caused when a person witnesses a traumatic, potentially life-threatening event. For example, combat soldiers and children who were sexually abused often times suffer from PTSD. Recent studies show the “trauma” in PTSD is the impact of stress on the brain structure of the victim, according to Dr. John Krystal, editor of Biological Psychiatry. The study conducted by Rao was inspired by an odd occurrence: clinical reports showed people with low cortisol levels were more likely to develop PTSD, and that cortisol treatment actually reduces the symptoms of PTSD. The study used a model of a rat to study its stress levels in relation to corticoids. Professor Chattarji from the National Center of Biological Sciences in Bangalore, India explains the outcome of the experiment: “ We were able to…. identify a possible cellular mechanism in the amygdala, the emotional hub of the brain [responsible for this odd occurrence.]” It turns out the number of synapses in the amygdala is a fairly accurate predictor of whether or not a person will have high or low anxiety levels. The corticoids given to the rats reset the number of synapses in their amygdalas, and brought down their stress level.

So What Does this Mean for Me?

If you’re a high-stressed, health conscious person like me, after reading this you might feel slightly better about your high stress levels, but don’t celebrate just yet. Even though we all have the potential to develop PTSD, not everyone does, so this study is relevant to only a portion of the population. Even if it were relevant to everyone, the stress hormones in the study were given to the rats under controlled circumstances, and if this were to become an actual therapeutic treatment for PTSD, the patient would most likely ingest corticoids under the close watch of their psychiatrist. In my opinion, the damage caused by high glucocorticoid levels far outweigh the benefits. So, take a deep breath and relax. Maybe go for a run or talk with a friend. Your stress will eventually go away.

 

 

 

Broken Heart Syndrome?

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On January 10, 2012

In Student Post

Yes, it’s real…

"Radiology Picture of the Day"

Photo taken by Radiology Picture of the Day, Edited by Yasmin Kibria

The broken heart syndrome is a temporary heart condition brought on by stressful situations–both excessively happy or excessively sad or tragic moments.  The symptoms may be brought on by the heart’s reaction to a surge of stress hormones.  A flood of stress hormones and adrenaline causes part of the heart to enlarge temporarily and triggers symptoms that can look like heart attack: chest pain, shortness of breath, irregular heart rhythm. The difference is that the factors that would normally cause heart attack, such as a blocked artery, aren’t present.

The University of Arkansas performed a study which looked at rates of “broken heart syndrome” — when a sudden shock or prolonged stress causes heart attack-like symptoms or heart failure — and found that it overwhelmingly affects women.

Dr. Abhishek Deshmukh, a cardiologist at the University of Arkansas who has treated women with broken heart syndrome, became curious about just how gender-specific the condition was.He found that, overall, women had about 7.5 times the risk of broken heart syndrome as men; in people under 55, women were at 9.5 times greater risk than men. Women over 55 were also three times more likely to suffer broken heart syndrome than younger women.

Why does this gender imbalance occur? Researchers are still working towards finding an answer, but it has been speculated that hormones come into play.

The way to mend a broken heart? Literally let it heal over time–it’ll be fine soon enough.

For further information:

http://healthland.time.com/2011/11/17/study-women-are-more-vulnerable-to-broken-hearts/#ixzz1fGLHn6V4

http://www.cbsnews.com/8301-504763_162-57326698-10391704/broken-heart-syndrome-more-common-in-women/

http://theweek.com/article/index/221655/broken-heart-syndrome-a-real-health-issue-for-women
 

Cheer up, its not depression, its just hypothydroidism

By

On December 4, 2011

In Student Post

Have you ever felt depressed and you don’t want to take pills to make you feel better? If the answer is yes then you might be in luck. A recent article in The New York Times reports on scientists finding a correlation between some cases of depression and levels of thyroid hormones in the blood. The specific hormones are Thyroxine and Triiodothyronine known as T4 and T3 respectively which regulate a wide variety of things such as body temperature and cognitive functioning. There are two cases which can have an irregular effect on the body. The first is hyperthyroidism which is having too much of the thyroid hormone which can cause a faster metabolism, sweating, weight loss and anxiety. The other case is hypothyroidism which is having too little of the thyroid hormone which can cause physical fatigue, weight gain, and depression which is what Dr. Russell Joffe, a psychiatrist, has been looking into. He says that “treating [hypothyroidism], which affects about 2 percent of Americans, could alleviate some patients’ psychiatric symptoms and might even prevent future cognitive decline.” Patients can be given synthetic thyroid hormones such as levothyroxine if their thyroid stimulation hormone, or TSH, is too high.

This subject is still controversial because it is hard for some doctors to tell what an abnormal level of TSH is since the normal levels can range from 0.4 to 5. This is only a problem if one doctor sees a patient with a 5 and thinks nothing of but if the normal level for the patient is 0.5 then the patient has 10 times as much TSH than they should have. Other cases can be difficult since it is sometimes hard to tell if it is a case of depression or if it is just stress and anxiety instead of mild depression. The research is still being done on trying to get a better sense of how the thyroid hormones and mood link.

Gamers solve some of biology’s most difficult riddles?

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On October 5, 2011

In Student Post

Who is solving some of biology’s most difficult puzzles and riddles? Obviously scientists, right? Think again. It’s the gamers.

An article recently reported that a revolutionary online game called Foldit, allows anyone, from gamers to students, to help predict the foldings and structures of  various proteins by playing competitively online. Protein folding is one of biology’s most difficult and costly problems, and is even a troublesome task for the most capable computers. A game such as Foldit requires much insight and an intuitive understanding to fold the proteins, allowing human intuition to triumph over a computer’s calculations. As we have learned in class, proteins are very prevalent in the human body. Hormones, enzymes, and antibodies are all examples of proteins, but many proteins are also associated with strands of viruses and diseases.

This is where you, as the gamers, come into the picture.

Since proteins play a large role in the functions of viruses and diseases, gamers playing Foldit can help design new proteins to help treat or provide a cure for the condition. The article reported that gamers have most recently solved the structure of an enzyme crucial for the reproduction of the AIDS virus. Knowing the structure, scientists are now able to find certain drugs to neutralize the enzyme and stop the reproduction of AIDS virus.

In class, we have learned that there is basically an infinite amount of combinations of proteins; there are 20 amino acids and can be combined to form chains of various lengths. We have also learned that the structure of a protein is also correlated with its function. The bonds present in the primary, secondary, tertiary, and quaternary structures of proteins are an important part to the shape and folds of a protein, giving the protein certain properties due to its shape. All of the information we have learned about proteins in our AP Biology class, can be seen and easily applied to the game, Foldit.

Now since we know the vital importance of proteins, do you want contribute to the next cure for a virus or disease? Get your game on and try Foldit out and see what you can do to solve some of biology’s most difficult riddles!

 

 

 

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