Diabetes is one of the most common chronic diseases in the world. Dr. Moalem states, "The World Health Organization estimates that 171 million people have diabetes—and that number is expected to double by 2030" (23 Moalem). There are two major types of Diabetes, Type 1 and Type 2. Type 1 diabetes is caused by the body attacking cells. These cells are specific for insulin production. Insulin is a hormone made by the pancreas, and this helps store glucose in various parts of the body that can later be used to be converted to fuel. Type 2 diabetes is where the body is able to produce Insulin, but possibly not produce enough impairing the absorbtion and conversion of blood sugar. According to Dr. Moalem, diabetics' urine smells (and tastes) particularly "sweet". Without any proper treatment, these "abnormal blood sugar levels can lead to rapid dehydration, coma, and death. Long term complications include blindness, heart disease, stroke, and vascular disease" (24 Moalem).
This relates to Big Idea 2 because in a normal human being, glucose is used to break down carbohydrates that we eat. However, diabetes disrupts this flow and causes the body to no longer produce the glucose needed. Glucose is essential for survival, Dr. Moalem says, "—it provides fuel for the brain; it's required to manufacture proteins; its what we use to make energy when we need it" (23 Moalem). Without this vital molecule, there can be a big shift in population and ecosystem levels.
Two types of diabetes have been explained above. However, there aren't only two types. Please identify and explain what the third type of diabetes is. Also, on page 25 Dr. Moalem says, "There's a big difference in the prevelance of Type 1 and Type 2 diabetes that is largely based on geographic origin. What are the geographical differences between the two types of diabetes?
(Elliot Rosen - erosen3@students.d125.org)
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ReplyDeleteDr. Moalem also discusses a third type of diabetes called gestational diabetes as it occurs in pregnant women. Gestational diabetes can result in macrosomia, which basically means a really chubby baby. This is caused by extremely high levels of glucose in the mother’s bloodstream, and in turn, crosses the placenta and feeds the fetus (pg 26). Gestational diabetes can raise the likeliness of the mother getting diabetes later in life. A woman is at higher risk to develop gestational diabetes if they are overweight. Furthermore, gestational diabetes is more common in African Americas, Asians, and Hispanics than in Caucasians. (Jane Brody, New York Times, Diabetes is a Risk in Pregnancy That Carries Risks Beyond)
However, recent studies have been made in which researchers have proposed a new type of diabetes: Type 3. After it was discovered by a team at Brown Medical School that the brain also produces insulin as well as the pancreas, further research was conducted. As it turns out, budding research shows that Alzheimer’s disease may be classified Type 3 diabetes. The term Type 3 diabetes refers to insulin resistance in the brain and corresponding inflammation. In a study performed by Rhode Island Hospital, a connection between Alzheimer’s and insulin was apparent. One’s Alzheimer’s disease progresses as a result of the brain developing a resistance to insulin. If the brain is resistant to insulin, the metabolism of lipids cannot proceed properly. Thus, due to the buildup of lipids in the brain, increased stress and inflammation take place, which are commonly symptoms of dementia. (Suzanne de la Monte, Dysfunctional Pro-Ceramide, ER Stress, and Insulin/IGF Signaling Networks with Progression of Alzheimer’s Disease, is published in the June 22, 2012, supplement of the Journal of Alzheimer’s Disease)
Researchers believe that Type 3 diabetes is similar to Type 2 diabetes and gestational diabetes in that the diabetes is affected by lifestyle choices. It is believed that eating more healthy saturated fats such as coconut oil can help optimize brain function by reducing the inflammation in the brain (which progresses Alzheimer’s) and even increase cholesterol absorption in the brain. Type 3, Type 2, and gestational diabetes are a matter of not only perhaps inheritance, but largely a matter of interaction with the surrounding environment (Big Idea 4).
Also on page 25, Dr. Moalem discusses the “big difference in prevalence of Type 1 and Type 2 diabetes that is largely based on geographic origin”. Type 1 diabetes has a higher rate among Northern Europeans (pg 26); the intense cold of sudden climate change in that geography being the natural selection driver to a diabetes genetic link (Big Idea 1). As we previously studied in our evolution unit, organisms can make adaptations and that certain traits may be favored for in order to help them survive in their specific environment (Campbell, pg 456). This is what Dr. Moalem suggests humans, specifically Northern Europeans, did in response to the extreme cold of their environment; the diabetes trait was selected for and passed down through generations as a defense against the extreme cold of the environment in that geographical climate.
On the other hand, the geography of where Type 2 diabetes is prevalent differs from Type 1. Type 2 diabetes is commonly seen across population groups. Where the percentage of the population who has Type 2 diabetes is higher, the percentage of the population who is obese is also higher. (Moalem, pg 26) Geographically, Type 2 diabetes is common in regions where perhaps sugar-heavy diets were more recently introduced to a population contrasting that population’s previous, less sugar-heavy diet. Unlike Type 1 diabetes, a specific geographic region does not carry a higher rate of Type 2 diabetes than another region. Instead, higher rates of Type 2 diabetes are observed among specific populations of people; not specific geographic regions.
Rachel Chang (rchang4@students.d125.org)