Review Of Dr. Sharon Moalem's 'Survival Of The Sickest'

"Why would genes that make people sick still be in the gene pool after millions of years?" Survival of the Sickest by Dr. Sharon Moalem with Jonathan Prince explains how diseases have a purpose in human survival, they are the tools that aided the human evolutionary process. The diseases were a contribution to the human evolutionary process. A collection of different cases and scientific research support the authors' hypothesis on the connection between certain diseases that plague us in modern times and the adaptability of our ancestors in contact with these diseases. The book begins with the introduction of a man named Aram Gordon. He was diagnosed with hemochromatosis. Hemochromatosis is, “a hereditary disease that disrupts the way the
body metabolizes iron," [1] The body would typically detect that there is a sufficient amount of iron in the blood so it is then reduced by the intestines. The excess iron will pass through as waste instead of being absorbed into the body. This disease would cause the body to ignore the iron level, resulting the tissue absorbing more iron than necessary. The surplus of the iron can lead to the damaging of major organs and joints. Thus, it is a chronic illness that can lead to liver failure, heart failure, joint pain, impotence, damage to glands in the body, and can lead to cancer. [1] [2] If left unchecked, it can lead to death. There is little disparity between the symptoms that Gordon experienced and the symptoms of hemochromatosis. He had physical difficulty, fatigue, a liver problem, and his heart seemed to beat irregularly. During this time, hemochromatosis was somewhat rare making it difficult to treat, in all honesty, doctors often failed to make a correct diagnosis so it was considered rare. It was also rather hard to diagnose as the symptoms could equal in another ailment. The illness was fully classified and found the primary gene responsible in 1996. However, its existence was first theorized in 1865 by a French Physician named Armand Trousseau. Since 1996, it was discovered that the disease was most occurring in people of Western European descent. Diagnosing the disease can be done by blood tests which reveal the amount of iron carried in the blood. One can also look at the genetics and see if there is a chance of it spreading since it is a hereditary disease, dietary habits must be modified, and there is the process of bloodletting. [2] Bloodletting was the ideal method to regulate the iron levels and prevent buildup. In the past, however, it caused more deaths than cured people. This study led to new evidence that bloodletting, in moderation, can be beneficial. Iron was beneficial for people as it is needed for almost every function for our metabolism. When the human body is under attack, the immune system deploys natural chelators-proteins that lock up iron molecules and take them out of circulation. Although excess iron is distributed through the body, one certain type of cell gets less than normal. That cell is a type of white blood cell called macrophages. They search for any troubles in the body and when one is located, they will try to subdue it and bring it to the lymph nodes. Iron is not only essential for us, but for many species of infectious bacteria. Normal macrophages were filled with iron, which feed the bacteria, resulting in their growth which are not able to access the lymph nodes to disseminate through the body. Hemochromatosis gave macrophages the advantage to successfully isolate and starve the infectious agents to death. This made them more effective against deadly pathogens like those which cause tuberculosis and bubonic plague. It appeared as humans had evolved to fend off diseases better than any other species. Shown in the beginning, Dr. Sharon made observations based on his experiences and research. In 1952, Eugene D. Weinberg conducted an experiment to test what could invalidate the affectivity of a antibiotic. In Petri dishes were three different samples. Though placed with antibiotics, one sample was overflowing with bacteria and this sample was iron. The iron had successfully neutralized the antibiotic. So much was learned from this information. Today, we understand much more about the complex connection and history between bodies, iron, infection, and hemochromatosis. The second chapter concentrates on the disease, diabetes.
The full scientific name is diabetes mellitus—which literally means “passing through honey sweet.” [3] Diabetes revolves around the gluscoes in someones body. Glucose is a monosaccharide, it was broken down from carbohydrates that the body consumes. It is essential for survival as it, "provides fuel for the brain; it’s required to manufacture proteins; it’s what we use to make energy when we need it." [3] The pancreas produces hormone called insulin to store the glucose for future use. "People with diabetes have high blood sugar because their body cannot move sugar... to be stored for energy. This is because their pancreas does not make enough insulin or/and their cells do not respond to insulin normally." [4] Diabetes can cause several symptoms like, blurry vision, excess thirst, fatigue, hunger, frequent urination, weight loss, and eye problems. Diabetes can affect the circulatory system, the kidneys, the feet, the nerves, and the reproductive system. There is a increased chance of heart attacks and strokes due to the thickening of blood vessel. [4] There are two of the most major types called , Type 1 and Type 2. Commonly they are called juvenile diabetes and adult-onset diabetes for the age demographic it is usually diagnosed in. Type 1 diabetes can occur at any age, but it is most often diagnosed in children, teens, or young adults. In this type, the body makes little or no insulin so daily injections of
insulin are needed to keep sugar and insulin levels relatively normal. It is caused when the body recognizes the insulin producing cells as foreign and attacks them. Type 2 diabetes makes up most diabetes cases. It most often occurs in adulthood however, because of child obesity it is being diagnosed more and more. They make insulin just at a low amount so many manage with medication. The third type is called Gestational diabetes as it is occurs in pregnant women. It was stated in other resources that in 1552 B.C., in Egypt was the first documentation of the ailment. Also around this time, ancient healers noted that ants seemed to be attracted to the urine of people who had this disease. "In the past Chinese physicians actually diagnosed and monitored diabetes by looking to see whether ants were attracted to someone’s urine." Having diabetes means having the urge to urinate large amounts of sugary urine. It can be diagnosed by urine test, which do tell of high blood sugar, it does not tell of diabetes. Another most common is the blood test. Type 2 can be helped with modifying the diet and exercising to lose weight. Certain diabetics can get a pack connected to the body which continually filters the blood. Younger Dryas is a period About 13,000 years ago, in which the retreating glaciers had a sudden reversal that lasted a thousand years. This period was called the because pollen from an Arctic wildflower called Dryas octopetala was found in mud cores dating back to 12,000 years ago. This wildflower only flourished during times of extreme cold. Just before the Younger Dryas, the people had thrived. The population declined after and yet humans still survived. Humans cannot survive in the freezing cold at the same time, that does not mean we did not evolve to manage through the cold. "Like alcohol, sugar is a natural antifreeze. The higher the sugar content in a liquid, the lower the freezing point." This could be how the people survived Younger Dryas. This adaptation might be similar to that of the wood frog’s, Rana sylvatica, which lives across North America. It can freeze solid and then recover completely when the temperature rises to the right level. One interesting bit of evidence is that those people with a propensity for diabetes are descended from people who lived in exactly those places hit by the ice age 13,000 years ago. This can allow people to create new treatment and a cure for diabetes. Based on the ideas and information shown by the experiments and observations on the wood frog, we could be able to survive and learn more on diabetes. In Chapter 4 of Survival of the Sickest, is the Glucose-6-phosphate dehydrogenase deficiency, otherwise known as Favism.
It was named after fava beans. The Greek scholar Pythagoras gave a warning to "Avoid fava beans." These beans were used as ballots at the time so he could have been stating to avoid politics. There is also a different theory, " Pythagoras was just worried his students would eat too many beans and, well, pass too much gas."[5] Many legends revolved around these beans. A cult called Orphics had believed those beans contained the soul of the dead. "Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (Favism) is a hereditary condition in which red blood cells break down when the body is exposed to certain drugs or the stress of infection." A person with this condition will not display any signs of the disease until their red blood cells are exposed to certain chemicals, or to stress. Symptoms are more are seen in men and they are, "Darkened urine, Enlarged spleen, Fatigue, Pallor, Rapid heart rate, Shortness of breath, Yellow skin color (jaundice)." [6] It was first unearthed during the Korean War in the 1950's. In that time period malaria was common in Korea. The soldiers were given drugs to protect themselves from malaria. Certain soldiers experienced anemia and some had their red blood cells literally bursting. They lacked the correct amount of the enzyme G6PD. G6PD get rid of free radicals so they don't create problems. Free Radicals are unpaired
electrons that look to pair up. As they search they can cause chemical reactions that can lead to the premature death of a cell. Fava beans produce free radicals which attack red blood cells. "Malaria is an infectious disease that infects as many as 500 million people every year, killing more than 1 million of them." [5] Malaria is serious disease that affects or is common in almost more than half of the world population. It turns out that people with this genetic deficiency end up being more resistant to malaria. By having favism and surviving malaria weeds out the ones without it, who will most likely die from the malaria. Malaria-causing parasites prefer normal red blood cells over G6PD-deficient ones. Scientists now try to experiment on blood cells based on the information that the children with the mutation had twice the resistance against malaria. The relationship between plants evolution affect on people are better explained by giving information on the different plants and how mother nature created them in such a way that benefits them to survive. The plants can harm us yet at the same time save us from something else. In modern times, it is not that important on why or how diseases are still here for many. It is mostly about finding a cure and how harmful diseases are. I found it intriguing how this book shows a new perspective on diseases and evolutionary biology. I had that mindset of all diseases being harmful yet now see they can have large benefits. It was very interesting to learn of the way to diagnose a disease and how challenging it is. I personally wanted to find out more about the effects that we as humans can have on bacteria. I quite enjoyed learning about this for it displayed a controversial issue, it shows the good and bad in everything and how moral code and science clash. I can imagine future research on these topics and they plague many people in modern day. There are many unanswered questions on the afflictions that affect us and the need to fix such issues are a priority to us. We will want and will strive to answer these questions. Though it may be hard to find cure perhaps make peoples live more easy though afflicted with these diseases. Find alternative ways for them to get what they need to keep the disease under control that will be more efficient and less of a hassle.