Monday, February 27, 2012
Another thing I found interesting is Dr. Sharon Moalem saying, "we don't know" throughout the book. One thing particularly, how little we know about possible epigenetic and maternal effects. Being a psych major I've learned a lot about the maternal effects on the baby, but I've never heard that my mothers genes will have an effect on my baby. Even though there is still complications and uncertainty with the data I find it very interesting that my mothers habits and environmental settings might have effects on my children, or that my genes can be carried to my granddaughter, through my daughter.
In Survival of the Sickest, Dr. Moalem mentions the idea of the Slavery Hypothesis in order to illustrate the mechanism of evolutionary medicine and its long term consequences. The Slavery Hypothesis is the idea that African-Americans have a predisposition for high blood pressure due to selection during the Middle Passage and ensuing enslavement. Dr. Clarence Grim hypothesized that slaves who survived the journey were likely to have been able to retain high levels of salt, as the death rate was high due to deprivation of food and water, as well as rampant illnesses that caused diarrhea and vomiting. Moalem does not mention that these claims are widely unsubstantiated. There is no proof of there being historical validity to the fact that Africa was salt-scarce and the statistics regarding this hypothesis lack supporting evidence.
However, it is interesting to note that the Slavery Hypothesis remains widely accepted today, despite the numerous criticisms that exist. It is still described as truth in medical textbooks and peer-reviewed literature, in the New York Times, the American Journal of Cardiology, Science News, and even by Oprah and Dr. Oz. As a result, ideas about genetic determinism and the biological basis of race have once again become a focus of scientific research. Acceptance of this hypothesis would presumably imply the acceptance of the idea that race is a biological, not social, construct. I agree with Moalem when he states, “From a medical perspective, it’s clear that specific diseases are more prevalent in specific population groups in a way that is significant and deserves continued, serious exploration” (65). However, this does become an issue when ideas such as that of eugenics arise. These ideas regarding the biological and social constructions of race are obviously a reoccurring theme in this class and remain an interesting topic of debate.
Survival of the Sickest offers an interesting perspective of evolution to the casual reader. The handful of Americans that do believe in evolution (joke) likely think in terms of ape-like creatures morphing into humans or survival of the fittest, some even considering the evolution of birds from dinosaurs or the mutation of viruses like HIV/AIDS. But Dr. Moalem leaves such readers with a very different appreciation for the wonders of this theory. He describes evolution as constantly dynamic, for better or for worse, and implicating all different organisms on the planet. I read the book quite avidly and quickly, especially given the accessible language and sensational examples. He starts off personal before getting into these examples, into his journey to investigate hemochromatosis, and subsequently the evolutionary reason behind numerous ailments. I especially enjoyed how he emphasized the genetic interaction of DNA of bacteria, viruses, and us as mammals. This portrays earth as a cohesive and dynamic enormous organism, all interconnected and evolving as a whole, subsequently taking the individualized notion of evolution out of people’s head, which I found very pleasing. If people adopted this former image into their political and everyday life, perhaps we would lead a far more satisfying and holistic reality.
I did maintain a few qualms about the book, mainly concerning the scientific evidence he uses to support his loose thesis. I wondered why he hadn’t used more concrete and solid research to support his claims, but rather became stuck on light ‘junky’ science. The last edition of the book was titled Survival of the Sickest: A Medical Maverick Discovers Why We Need Disease. Upon seeing this I was also left me wondering every time I read something especially surprising; what would non-mavericks in the field think of this? Why did he need a professional speechwriter to help him write this popular science book? There is a point at which Sharon states that some of his claims are still being investigated, or some words to that affect. Nevertheless, I believe he was more intent on offering an invigorating and different perspective on existence, and for me he succeeded to some degree.
On page 88 of Germs, Guns and Steel, Jared Diamond mentions in passing the role that large, domesticated animals serve in nourishing early agricultural communities—they provide meat, aid in crop production, can be used as farm hands, and can be milked. These mammals, Diamond says, “yield several times more calories over their lifetime than if they were just slaughtered and consumed as meat.” For a family with a plot of land and many mouths to feed, this self-sustaining model is fantastic. Compared to other species in the animal kingdom, though, humans are quite odd. We’re the only mammals that consume milk after infancy, surprising because lactase, the enzyme needed to digest lactose, is highest just after birth and diminishes with age (hence lactose intolerance), suggesting that milk is perhaps only necessary and beneficial in the first few months of life.
When I think of milk and milk products, one thing I always bounce back to is who in their right mind decided to milk an ungulate’s udders?? It’s a little bit weird! I’m not that naïve, though—I realize that milking is only mimicking what babies of many species do to obtain nutrients and calories from their mothers. But why, after exhausting our human mother’s resources, do we find it necessary to switch to milk from other species and use it for milk, cheese, yogurt, ice cream and other dairy products? According to the ever-trusty Wikipedia, milking animals coincided with the development of agriculture, appearing independently in 9000-7000 BC in Southwest Asia and 3500-3000 BC in the Americas. There are many theories about how and why humans came to milk animals, a marked departure from the diet of a hunter-gatherer, who would probably consume virtually no dairy. While it remains unknown exactly when and how dairying came to be, it’s certainly a livelihood for many and a considerable part of the SAD (Standard American Diet) and diets in other parts of the world.
As an aside, from the general information that I know about lactose and lactase and human’s uniqueness in dairy consumption, I have to question doctors’ recommendations to drink more milk. The idea that the calcium in milk is necessary for strong bones and proper growth (which can be found in other foods) is one of the government’s party lines (see My Plate and past food pyramids). If dairy is a relatively new addition to the diet, though, is it really necessary?
Additionally, the bit Moalem wrote about having to pee whilst being cold was entirely too true. Whenever I'm on the ski mountain, I always get the urge to pee at random intervals. It always happens to be when I'm at the coldest part of the mountain too, right before I am about to go down the trail. Really??? I absolutely hate the feeling because it is so uncomfortable and such an annoying process to have to go to the bathroom while at a ski place. Internal pressure as a reason seems to make some sense because at the coldest part of the mountain, there is more pressure from the inside of your body, and the increased blood flow to certain pars in order to keep you warm. This seems like an extremely debated about question that I too would like to know the answer too. Why do we have an urge to pee whenever it gets really cold outside?? Any thoughts...
Monday, February 20, 2012
Reading Survival of the Sickest makes me wonder about the ways in which society now will evolve in the future and what kinds of adaptations we'll develop. Since our diets have become vastly different because of the introduction of processed foods, we might be able to develop a better system to get rid of excess fat and sugar in our diets and our bodies will naturally eliminate the problem of obesity, diabetes and heart disease. Or, going back to Why Zebras Don't Get Ulcers, we may create an adaptation to our hormonal responses to stress so we can all live happily and carefree even when our student loans are overdue and our jobs suck. Or in order to speed up becoming a happier and healthier society, somewhere down the line we might be able to use what we know about evolution and genetics to develop drugs that are specially catered to a specific genetic makeup in order to make them more effective for each individual. It's kind of comforting to think that our bodies can actually evolve to make us better overtime, and that nature possesses all the tools we need to cure every kind of disease. The problem is harnessing those tools in order to make them more effective sooner rather than later.
Chapter VII in Survival of the Sickest really stood out to me in light of our extensive discussion of factors that may contribute to low-birth weight children. In particular, the fat mouse experiment at Duke which showed that a nutrient-dense diet during pregnancy can lead to a fat mouse giving birth to a skinny mouse. What else caught my attention was the fact that the first few days of conception may have important implications over the course of that child’s life. This struck me as just another factor that contributes to inequalities among society. We learned in lecture that the wealthy tend to plan their pregnancies more whereas the lower classes tend to have unplanned pregnancies. Assuming everybody takes equal precautions for better health during pregnancy, if lower classes don’t know they’re pregnant until further into it then they’re less likely to cut back on behaviors that may harm the fetus, such as smoking. This chapter also provided information about how being exposed to smoking can flip on or off certain genes, which could further harm the health of the fetus. This seems to imply that they have less of a chance to ensure that their children will have better health and the more the inequalities in society will continue. I was reminded of Why Zebras Don’t Get Ulcers when it’s mentioned that “The more unequal are incomes in a society, the more pronounced will be the disadvantages to its better-off members from public expenditure, and the more resources will those members have [available to them] to mount political opposition” (Sapolsky, 380). While this particular passage is emphasizing that the wealthy in unequal societies will derive more of a benefit from spending on private goods than on public goods which further divides the society, there is still the idea that the wealthy can better afford prenatal care and can better plan for the birth of their children. This being the case and assuming that the first few days can have tremendous implications in epigenetics, then the wealthy continue to benefit the most. But it should be addressed that inequality in society has costs on both sectors of society since the wealthy are essentially isolating themselves from the rest of the society while everybody else has to live with the consequences of living in it. This is certainly the case in America with increasing income inequality. Although lower classes are harmed the most, it hurts all of society to have this inequality continued. I’m reminded of Adam Smith’s saying that “No society can surely be flourishing and happy, of which the far greater part of the members are poor and miserable.” Not only does income inequality negatively effect lower classes because of worse access to medical resources, poorer quality of foods, but as we read in Why Zebras Don’t Get Ulcers, being on a lower rung in the social hierarchy has negative effects psychologically which can manifest into having a negative physical impact. It makes me wonder, what if the fat mouse was provided a nutrient dense diet but also had to suffer stress? Would it still give birth to a skinny mouse? If so, that provides a glimmer of hope for preventing health complications and reducing inequalities.
On a completely different note, the Atlantic recently published an article that elaborates on T.gondii, the parasite carried by cats discussed in Chapter V of Survival of the Sickest http://www.theatlantic.com/magazine/archive/2012/03/how-your-cat-is-making-you-crazy/8873/ It’s weird to think that something as innocuous as a housecat may actually be impacting our mental health.
In "Survival of the Sickest" Dr. Sharon Moalem exposes that some diseases are actually very sophisticated, adapted responses to former environmental threats to human health. He focuses especially and continuously returns to his very personal discussion of hemochromatosis--a disorder which traps and locks excess iron in the body (albeit unevenly). I had always been under the assumption that iron is almost always a good thing for the body and as a vegetarian, I find myself on a perpetual quest to add more of it to my diet. Moalem, however, proved me very, very wrong as he discussed how those with hemochromatosis (which neglects to spread iron to certain microphages in the body) and anemia are actually far less susceptible to certain diseases and bacteria which feed on iron as fuel. Iron is constantly added as a supplement in many of the pulses, grains, cereals, and multiple other foods we eat and also an additive in baby formula.
Reading all of this brings me back to Ewald's theory (pg. 120-123). I believe that the Guinea worm disease may have not been eradicated earlier because "bacterial evolution gives bacteria an advantage over us". Although it may seem that the eradication process may come to a final end soon, I won't be surprised if it won't happen by the year 2020. I wonder if more practical ways can help further the process such as educating the children since they are the majority of victims.
From what I've read (up until chapter 10), I thought Guns, Germs, and Steel was interesting in some ways, but overall kind of dry. I admire the author's intense detail of possible cases and examples supporting the usually all-inclusive hypothesis he sets up (such as the conquering of Latin America by the Spaniards), but personally I was more interested in the way he set up many of his arguments with questions that supposedly have been answered by (usually) white philosophers/researchers/scientists.
One such discussion was about human intellect and how some try to say that white/European people are genetically disposed to being smarter. Diamond goes on to refute this fact by putting this into perspective. Due to the advance of medicine and technology, more and more arguably "less fit" people are passing on their genes to subsequent generations. However, in these isolated societies such as the Guineans, tougher living conditions and the unforgiving nature of disease and disaster have only allowed the "fittest" to survive. I thought that was very interesting, because I, usually think of intelligence in the Western sense, in terms of a knowledge bank. Diamond points out that the people he encountered in New Guinea were among the most intellegent people he's met, but not in a book or subject sense. Additionally he noted that they could take up industrialized methods and techniques very quickly if taught.
On the whole, I was also interested in his emphasis on luck and geography. He points out that geography directly affects wildlife diversity and potential problems for species living in certain areas, among countless other factors. These factors can then be used to how some human societies were able to take advantage of their situation and prosper. I had always learned the history of such sequences was more related to the psyche of the people - the smart and strong conquered, but Diamond's intricate explanations showed me that chance and environment were much more important in the development of history than most think. I thought this ties into our discussions regarding health outcomes in society being a direct effect of one's environment, starting with pre-natal conditions. By reading this, I am leaning much more toward the idea that health is far more effected by environment than genetics, barring genetic disease. I look forward to maybe reading about more of the health effects in history in the second half of the book.
Sunday, February 19, 2012
Monday, February 13, 2012
This morning I happened across an an interesting article in the Bloomberg News that seemed quite relevant to class. A Harvard University study suggests that childhood abuse can lead to physiological disruptions in the hippocampus, which causes adult depression and drug abuse down the road. Young men who had histories of child abuse demonstrated differences in parts of the brain where new neurons are generated, and have less dense (up to 6.5%) hippocampus tissue, which processes emotions, fear, memory etc. Dampening activity in this part of the brain has been linked to depression and schizophrenia. In addition people who have endured this type abuse are more biologically sensitive to stress, and such factors may shorten their life expectancy by as much as 20 years, other studies indicate. On a more cheery note, it is also noted that certain drugs and lifestyle changes can prompt the formation of new neurons!
I think this was interesting in context of our conversation of genetics vs inheritance. One would assume that changes in the composition of our brain and psychiatric condition is overwhelmingly genetic. The physiological manifestation of a social phenomena (such as child abuse) is a fascinating contradiction to this genetic excuse, and instead indicates that many 'inheritable' traits, such depression may have roots in behavior. Perhaps parents who mentally and physically abuse their children have higher chances of being substance abusers or depressed, resultant from a long chain of child abuse in their family. The inheritance of child abuse! This parallels our discussion of social conditions vs genetics in the inheritance of low birth weight risk. The article briefly delves into the financial burden of child abuse on society and healthcare, which I also found interesting.
Anxiety is a psychiatric disorder that Sapolsky describes as being “rooted in cognitive distortion” (319). An anxiety-prone person’s thoughts create a psychological state of dread and apprehension, which in turn affects how they feel and act. As a result of the excessive worry, people diagnosed with anxiety disorders have abnormal, chronically overactive stress responses, which leads to an increased risk of many diseases. A widely used method of dealing with anxiety disorders is through the use of cognitive behavioral therapy. Cognitive behavioral therapy is an approach that attempts to systematically recognize and eliminate dysfunctional thoughts, which will change how we feel and our behaviors. While this method has been proven to be effective, there has been a rise in the usage of alternative treatments, a major one being mindfulness mediation.
Sapolsky mentions the use of meditation as a technique for managing stress. Meditation is used to increase our ability to relax, which in turn should increase our ability to cope with stress more effectively. While there are many different forms of meditation, the form that the majority of the scientific studies have focused on is mindfulness meditation. The goal of mindfulness meditation is to make create stability and peace in our minds while increasing awareness. Researchers have been studying the effectiveness mindfulness mediation based treatments in reducing anxiety. Through randomized trials, it has been shown that mindfulness meditation therapy can significantly reduce anxiety, as well as successfully improve mood, functionality, and quality of life.
A study published in Psychiatry Research: Neuroimaging, used images from the brain throughout an eight week long mindfulness mediation based stress reduction group to show that actual structural changes occur to our brain when we meditate. Reductions in stress were found to be associated with decreased grey-matter density in the amygdala, which, as Sapolsky explained, plays a very important role in anxiety disorders. These studies show that mindfulness meditation should be increasingly used as a therapeutic technique to reduce anxiety. Meditation could possibly be used as a prevention method before a person is inflicted with a stress related disorder. It would be interesting to possibly study other forms of meditation in order to see if their effectiveness in anxiety reduction differs. Another interesting possible study would be to track the long term effects of meditation and health outcomes in order to discover if any other ailments can be treated or prevented with such a method.
Sunday, February 12, 2012
In a study spearheaded by Dr. Stanley Nattel of the Montreal Heart Institute Research Center, “Canadian and Spanish scientists prodded young, healthy rats to run at an intense pace, day after day, for three months, which is the equivalent of about 10 years in human terms. The training was deliberately designed to mimic many years of serious marathon training in people.” By the end of the study, these formerly healthy rats exhibited scarring and structural changes in their hearts and were more prone to irregular heartbeats, not unlike in humans. “Interestingly, when the animals stopped running, their hearts returned to normal within eight weeks. Most of the fibrosis and other apparent damage disappeared.”
This study, designed to assess the toll that sustained, intense training takes on a person’s physiology, highlighted exactly what some may find the definition of insane. As Sapolsky on page 123, “sit with a group of hunter-gatherers from the African grasslands and explain to them that in our world we have so much food and so much free time that some of us run 26 miles in a day, simply for the sheer pleasure of it. They are likely to say, “Are you crazy? That’s stressful.”” He also addresses the negative correlation between long distance running and fertility (because of low testosterone and estrogen production) and bone health.
I found this topic worth looking into because, in general, we try to get people to exercise more (if at all) to reap its many physical and psychological benefits, but once in awhile a story breaks of a death during a marathon or debilitating injury from improper training and it’s interesting to see there are some people who find pounding the pavement for 26.2 (or longer!) an enjoyable pastime. More may not always be better, but for whomever wants to wake up early for long training runs dedicate their free time...more power to them!