BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Obesity (Page 2 of 2)

Artificial Sweeteners: Not So Sweet After All?

425555319_86d3866d4b_o

Amy van der Hiel

A recent study conducted at the Weizmann Science Institute suggests that artificial sweeteners may trigger health problems instead of benefiting people. This is important because not only is saccharin in artificial sweeteners, but it is also found in salad dressings, vitamins, and in low/zero calorie items we often eat.

Previously, sweeteners were known to pass through the gut undigested, therefore allowing people with health issues to use the sugar substitute. Recent tests on mice and humans found that saccharin actually interferes and alters microbiota bacteria found in the gut and small intestines, leading to serious conditions such as obesity and diabetes.

Mice were monitored for 11 consecutive weeks when given drinking water doped with saccharin and the results showed they had abnormally high levels of glucose in their bloodstream. When food is digested it is broken down into glucose, the most common carbohydrate, and then enters the bloodstream to either be used as fuel or stored. When glucose metabolism is blocked, the blood glucose level is high. The test was repeated with mice on high-fat diet and the results were the same, showing that the saccharin had the same effect irrespective of the animal’s weight. Four of seven humans that ate a high-saccharin diet were also found to have an impaired glucose metabolism.

Why the microbiota are affected is still unknown as the test is preliminary, but the conclusion has been made that certain saccharin sugar substitutes are not simply passing through the intestines.

Original Article: https://www.sciencenews.org/article/artificial-sweeteners-may-tip-scales-toward-metabolic-problems

Photo Credit: https://www.flickr.com/photos/amyvdh/425555319

More Links:

http://www.biologynews.net/archives/2014/09/17/gut_bacteria_artificial_sweeteners_and_glucose_intolerance.html

http://well.blogs.nytimes.com/2014/09/17/artificial-sweeteners-may-disrupt-bodys-blood-sugar-controls/

http://wis-wander.weizmann.ac.il/gut-bacteria-artificial-sweeteners-and-glucose-intolerance#.VB48n4ARD1h

Can we fix the expensive problem of obesity??

Today, America faces what can be considered an “obesity epidemic”. An estimated 69 million americans are considered obese, and obesity is the #2 cause of preventable death in America. Obesity can lead to a number of dangerous conditions and even life threatening conditions. Consequences of obesity include coronary heart disease, type 2 diabetes, different types of cancers, stroke, live disease, sleep apnea, arthritis and more! In addition to health consequences, the epidemic of obesity in america also includes severe economic consequences.  In 2002, the estimated health care expenditure for obesity-related issues was $147 billion

taken from WikiMedia

 

 

The statistics concerning obesity, childhood obesity, money lost due to obesity etc. are shocking. America is deeply affected by a preventable issue affecting roughly 35% of adult americans and 20% of youth americans. Scientists and doctors have long explored ways to address this issue medically. Until recently, it was believed that the part of the brain controlling appetite is fully developed before birth, and therefore, cannot be altered. As genetics play a big role in weight and appetite control, the ability to alter the appetite control center (the hypothalamus) would be a huge step in “curing” obesity.

However, “research published in theJournal of Neuroscience has identified a population of stem cells capable of generating new appetite-regulating neurons in the brains of young and adult rodents”. This information suggests that altering the appetite regulation system in humans is a possibility.

There is now hope that “the neural circuitry that controls appetite is not fixed in number and could possibly be manipulated numerically to tackle eating disorders.

Link to Main Article:

http://www.sciencedaily.com/releases/2013/04/130405064253.htm

Link to Additional Articles:

http://www.cdc.gov/obesity/adult/causes/index.html

http://obesityinamerica.org/statistics/

http://www.getamericafit.org/statistics-obesity-in-america.html

Link to Photo:

http://upload.wikimedia.org/wikipedia/commons/e/e7/Medical_Complications_of_Obesity.svg

 

 

The New Way to Diet

The New Way to Diet 

Today, obesity is a global epidemic effecting millions if not billions of people world wide. Whether it be a few pounds or even a couple hundred pounds, there are countless people out there looking for a way to drop excess weight. Some they try dieting and altering what they eat and others revert to more serious methods, such as surgery. Recently a new procedure has been created that can help those suffering from obesity. Called  GECA or (gastric artery chemical embolization), this surgery can change the lives of millions of individuals.

* Click on image for link to flickr page

GECA is a surgery much safer than a liposuction that can literally make you less hungry  This relatively simple surgery is carried out by blocking off an artery that leads to the stomach. Doing this cuts off the blood supply to a certain section of the stomach that can produce the hormone called gherlin. This hormone controls our cravings to eat food and the sensation we call ‘hunger.’ Removing this hormone from our bloodstream would take away the desire to constantly eat. We would still be hungry, but just for less. With the desire to eat dissipating  one’s intake would go down and, with some exercise, the pounds would drop easily.

What do you think of this new procedure?

Source Article: http://www.medicinenet.com/script/main/art.asp?articlekey=168362

 

 

 

Epigenetics, Dads, and Obesity

 

By Ynse. Photo from Flickr http://www.flickr.com/photos/ynse/1531699476/

 

It turns out that kids with obese fathers have unique epigenetic changes that can affect their health… for the worse.

According to a recent study, “children with obese fathers have different epigenetic markings on the gene for insulin-type growth factor 2 (IGF2) than children with fathers of normal weight.”

Children with obese fathers have less methylation on a specific region of the IGF2 gene. Sadly, this occurrence is linked with many types of cancers such as ovarian cancer.

However, it is too soon to tell if these epigenetic changes are directly linked to the children’s’ health.

According to the biologist Gudrun Moore, “it is tempting to over-emphasize the role of a small number of parent-of-origin expressing genes and to speculate about the effects of modest variation in methylation, but we must not be too hasty to blame either parent for their offspring’s health outcomes.”

However, other researchers are sure that that your parent’s environment and habits affect children’s health.

According to Michael Skinner, this research “suggests that environmental epigenetics might be the mechanism for these effects.”

Maybe now both the mother and father have to be careful about what they eat during the pregnancy. Sorry Dads-to-be, you are going to have to eat healthy now!

For more information on epigenetics and health, you can visit these links.

http://www.economist.com/news/science-and-technology/21565573-some-effects-smoking-may-be-passed-grandmother

http://healthletter.mayoclinic.com/editorial/editorial.cfm/i/249/t/Understanding%20epigenetics/

Photo credit: http://www.flickr.com/photos/ynse/1531699476/

Pull-Ups, Biology, and Our Sexist Society

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/

S U G A R !

Mmm, sugar, so yummy…

Dr. David Katz, the director at the Yale Prevention Research Center writes of the negative effects of sugar in our lives in his article “Medicine, Museums, and Spoons Full of Sugar.” It’s a fact: kids and adults are eating way too much sugar, and this excess is known to contribute to the obesity epidemic.  Obesity itself causes other complications like diabetes and other diseases.

We’ve always known that having too much sugar is a bad thing, but how does it all add up? Soda like Coke, Sprite and Fanta are regarded by some public health experts as “liquid candy.”  Soda adds tons of calories and sugar to a typical diet.  So there you have it: soda is one of the many guilty culprits in the add up of sugar.

Taken by Yasmin Kibria

That’s only part of the problem–most of the excess sugar actually comes from foods.  “A how much is too much? According to Dr. Andrew Weil, everyone has a different response to sugar.  For some it triggers modd swings, brings on a sugar rush followed by a crash, and for some, there are no noticeable effects.  Sugar tends to drive obesity, high blood pressure, and Type II diabetes in people who are genetically programmed to develop insulin resistance.

How does too much sugar lead to obesity? According to Dr. Robert Lustig, sugar causes more insulin resistance in the liver than does other foods.  The pancreas then has to release more insulin to satisfy the liver’s needs.  High insulin levels obstruct the brain from receiving signals form leptin, a hormone secreted by fat cells.

Zoos Killing Elephants?

Credit: xrayspx on Flickr

According to a study conducted by zoologists, elephants that are kept in captivity die much earlier than elephants that remain in the wild. Wouldn’t you think that elephants being kept at a zoo would be more likely to live longer? After all, they are getting regular feedings that require little to no effort on their part, and they are purposely kept away from any predators . So what’s the problem?

Ironically, most of these elephants end up dying of obesity (can you imagine how big an obese elephant might be?), because they eat and eat and eat, but don’t get any exercise in their limited spaces at the zoo. In addition to that, the elephants die from the stress of being transported to a zoo, and being separated from their mothers.

According to a study led by Ros Clubb (wildlife scientific officer at the RSPCA), African elephants lived (on average) 16.9 years in captivity, while free African elephants lived (on average) 35.9 years.

In another study, led by the Department for Environment, Food, and Rural affairs, seventy-seven elephants were studied in thirteen UK zoos. The results showed that the elephants spent 83% of their time indoors, 71 of the 77 elephants were overweight, and only 11 could walk normally.

That doesn’t mean that zoos are horrible for all animals, just read this article, but they certainly aren’t helping out the elephants!

 

Are bad bacteria really bad?

That moment you finish pumping your gas and you think about all of the other hands that may have touched the same nozzle, so you become so disgusted until you remember that there is a bottle of Purell in the car. You suddely have the urge to open the cap, squeeze half of the bottle into your hand and rub them until your hands have never felt cleaner. The soothing idea that only .01% of bacteria may still lay on your hand rushes upon you and then you are able to go about your day picking up food with your fingers and proceeding to place it in your mouth.

 

Funny thing is, studies show that using Purell is not good for our hygiene. Does this mean that using Purell and  other anti-bacterial creams, sprays and medicine have actually been the cause of some of our ailments? Purell should not  be used on a day to day basis because it removes 99.99% of germs that means that you are not only killing the bad germs but also the good germs, and maybe leaving just .01% of them behind. Anti-biotics have a similar affect as Purell.

 

The hypothesis:

H. pylori in the stomach- photo taken from healthmedicalarticles.com

Dr. Blaser, a profesor of microbiology at NYU, decided to research what are the consequences of killing all of the bad bacteria in the human body by using anti-biotics and anti-bacterial creams. He came upon the hypothesis that “the overuse of antibiotics increase the risk of obesity.”  He discovered that anti-biotics have been prescribed to patients with ulcers and gastric cancer, even when the patients showed no symptoms. These anti-biotics actually kill a bacteria called Helicobactor pylori (H.pylori). Studies show without H.pylori, a hunger hormone ghrelin, increases its secretion after a meal, when the hormone is actually suppose to drop in secretion levels. Thus by removing H. pylori the person is actually eating more frequently and consequently gaining more weight. It is also shown the children who have been treated with regular doses of anti-biotics to treat throat and ear infections had a marked increase in body fat while maintaining a constant diet. So can it be blamed on doctors that what they say is so-and-so “baby fat” is actually a result of their over prescription of anti-biotics when we had ear infections? Ok. maybe I went a bit to far, but it seems simple, some bad bacteria is meant to be in our system, not only to keep us healthy but also so that we can form some resistance to the bad bacteria.

Superbugs? 

By overusing anti-biotics we have created superbugs such as methicillin-resistant staphylococcus aureus. What a big word, what does it mean? Methicillin-resistant staphylococcus aureus is a bacteria better known as MRSA and is derived from a bacteria that was known to create staph infections. That bacteria was able to be treated through an assortment of anti-biotics but this new superbug does not respond to most anti-biotics. Thus more and more anti-biotics are being given to MRSA patients resulting in a large concern for obesity in these patients.

Back to the Hypothesis of Dr. Blaser: 

Yu Chen, an epidemiologist at NYU, has agreed with Dr. Blaser that the overuse of anti-biotics and the correlation to H. pylori has also been the cause of many childhood infections such as: hay fever, asthma, and skin allergies. Peter Turnbaugh, a Harvard University geneticist, and  Dr. Jeffrey Gordon, a gastroenterologist at Washington University in St. Louis have also agreed with Dr. Blaser that the use of anti-biotics alter the healthy ratios of bacteria in the stomach, which results in an on-set of weight gain.

This is just the start of Dr. Blaser’s studies, he was granted over 100 million dollars from the National Institute of Health and plans on researching more bacteria, not only H.pylori. SO, what does this mean? Can anti-biotics be killing too much bacteria? Should we be waiting until our sickness has reached its peak before we take an anti-biotic? What about Purell is that creating superbugs?

A solution may be to wash our hands before we eat, but not be too narcotic and kill all of the bacteria that may lay on our hands, what do you think?

 

For more information please go to:

http://www.nytimes.com/2011/11/01/health/scientist-examines-possible-link-between-antibiotics-and-obesity.html?_r=2&ref=science

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

http://www.health24.com/natural/Probiotics/17-1940,33634.asp

 

 

 

 

 

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