Heavily stressed by Dr. Jen Beshel in her talk and research was the fact that obesity is no longer an American problem, but a global one. Obesity has been seeping in and increasing its presence across the world, even in parts where it might not have been expected. For example, Thailand's Public Health Department recently have had to issue a health warning for their nation's Buddhist monks, as obesity has reached alarming levels. Some 50% of monks have been medically diagnosed with morbid obesity and though the monks, who due to Buddhist practice, do not eat after midday, are still struggling to lose weight and instead are gaining it.
In her studies with flies, Dr. Beshel had yet to figure out if obesity led to permanent changes within the brain. However, a recent study, published August 22 in Science Translational Medicine, claims that obesity leads to a dysfunction of the receptor for leptin meaning it may have found the answer to why it is so difficult for those with obesity to get rid of it.
This study found mice subjected to obesity through a high-fat diet secreted more of a protein called, metalloproteinase-2, MMP-2. Researchers found that MMP-2 actually cleaves off a part of the leptin receptor in the hypothalamus, supporting the finding of Dr. Beshel's study which located the neurological receptors for leptin versus the fat body receptors. The study went on to silence the MMP-2 gene and found full obesity recovery and when the MMP-2 was reinjected into the brains of the mice with the MMP-2 gene knockout, they regained obesity symptoms.
Researchers proposed a dual-mechanism for the pervasiveness of obesity: 1) High-fat/High-calorically dense diets promote inflammation within the hypothalamus(previous research found that these diets induce low-grade chronic inflammation), 2) Higher inflammation leads to greater expression of MMP-2 which impairs the leptin receptor, increasing leptin insensitivity. Essentially, the more individuals ate nutrient-lacking, calorically-dense diets, the more their production of MMP-2 increased which decreased their leptin sensitivity. With a decreased sensitivity to leptin, the individuals could not understand that they were satiated, leading to more eating and even more damage to the leptin receptors.
Despite these findings, obesity still remains unsolved. Dr. Beshel's question of whether obesity has a "too-much" threshold, where crossing that line prevents the body from being able to reverse the effects of obesity, has not been answered yet. This study, though promising, cannot be the solution to obesity. First, hypothalamic injections aren't possible in humans, so MMP-2 concentrations cannot be spot reduced and the effects of a global reduction of MMP-2 has not been studied for viability. Though obesity keeps spreading, studies such as this one and researchers like Dr. Beshel will hopefully make it something we can shed off and keep off.
Works Cited
Suhartono, Muktita. “In Thailand, 'Obesity in Our Monks Is a Ticking Time Bomb'.” The New York Times, The New York Times, 12 Aug. 2018, www.nytimes.com/2018/08/12/world/asia/thailand-monks-obesity.html.
Stetka, Brett. "A Molecular Reason Why Obese People Have Trouble Losing Weight." Scientific American, Scientific American, 22 Aug. 2018, https://www.scientificamerican.com/article/a-molecular-reason-why-obese-people-have-trouble-losing-weight/
In her studies with flies, Dr. Beshel had yet to figure out if obesity led to permanent changes within the brain. However, a recent study, published August 22 in Science Translational Medicine, claims that obesity leads to a dysfunction of the receptor for leptin meaning it may have found the answer to why it is so difficult for those with obesity to get rid of it.
This study found mice subjected to obesity through a high-fat diet secreted more of a protein called, metalloproteinase-2, MMP-2. Researchers found that MMP-2 actually cleaves off a part of the leptin receptor in the hypothalamus, supporting the finding of Dr. Beshel's study which located the neurological receptors for leptin versus the fat body receptors. The study went on to silence the MMP-2 gene and found full obesity recovery and when the MMP-2 was reinjected into the brains of the mice with the MMP-2 gene knockout, they regained obesity symptoms.
Researchers proposed a dual-mechanism for the pervasiveness of obesity: 1) High-fat/High-calorically dense diets promote inflammation within the hypothalamus(previous research found that these diets induce low-grade chronic inflammation), 2) Higher inflammation leads to greater expression of MMP-2 which impairs the leptin receptor, increasing leptin insensitivity. Essentially, the more individuals ate nutrient-lacking, calorically-dense diets, the more their production of MMP-2 increased which decreased their leptin sensitivity. With a decreased sensitivity to leptin, the individuals could not understand that they were satiated, leading to more eating and even more damage to the leptin receptors.
Despite these findings, obesity still remains unsolved. Dr. Beshel's question of whether obesity has a "too-much" threshold, where crossing that line prevents the body from being able to reverse the effects of obesity, has not been answered yet. This study, though promising, cannot be the solution to obesity. First, hypothalamic injections aren't possible in humans, so MMP-2 concentrations cannot be spot reduced and the effects of a global reduction of MMP-2 has not been studied for viability. Though obesity keeps spreading, studies such as this one and researchers like Dr. Beshel will hopefully make it something we can shed off and keep off.
Works Cited
Suhartono, Muktita. “In Thailand, 'Obesity in Our Monks Is a Ticking Time Bomb'.” The New York Times, The New York Times, 12 Aug. 2018, www.nytimes.com/2018/08/12/world/asia/thailand-monks-obesity.html.
Stetka, Brett. "A Molecular Reason Why Obese People Have Trouble Losing Weight." Scientific American, Scientific American, 22 Aug. 2018, https://www.scientificamerican.com/article/a-molecular-reason-why-obese-people-have-trouble-losing-weight/
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