Examples of physiological changes in H. sapiens as a result of diet over a period of human evolution. Created by Nickele Morgan.
I found that there were several major events in hominid evolution including: increased meat eating, cooking of food, controlled use of fire, milking of cattle, among others (Arjamaa & Vuorisalo, 2010). Events like these caused evolutionary changes in hominids from a gene-culture perspective.
Increased eating of meats helped to provide more fatty acids, which would help hominid brain evolution. Today many people take fatty acid supplements (such as fish oil pills) to help stay healthy, such as providing benefits to the cardiovascular system (Stokel, 2011).
I wonder if the lack of these fatty acids has the opposite effect on brain development in people today. Are we de-evolving? If our ancestors needed fatty acids, carbohydrates (fresh vegetables), etc. and we are depriving ourselves of these very things now, how can we all expect to continue to evolve (for the better) because of these dietary choices?
Different cultures seem to be able to evolve separately. Evolutionary changes in lactose tolerance and gluten intolerance's are taking place right now. Hawks (2013) stated “People that have been dairying for a long time have lactase persistence. People that have been farming with grains, wheat, rye, or rice for a long time, have additional gene duplication of a gene called amylase, which breaks down starch into sugars. These co-evolved with genetic changes to make people better suited to them.”
Hawks (2013) also discusses how people living at high altitude are able to breathe easier because of their genetic adaptations; capillaries in their cells have changed the oxygen-carrying capacity to compensate for the higher altitudes.
It appears that how we live will determine the direction of evolution whether it be the food we eat or the environment in which we live.
Fast Food Impacting Evolution[]
The US is the leading consumer of fast food followed by France, Canada, United Kingdom, and South Korea (Sammy, 2013). Research shows that as the intake of fast food increases the obesity rate increases right along with it (Jeffery & French, 1998). Obesity in the US has reached epidemic proportions. There are many negative long term effects of fast food on health. In children it has been found to cause type 2 diabetes, asthma, obesity and liver disease, and in adults it is tied to stroke, cardiovascular disease, and cancer (Corporate Accountability International, n.d.). Most of these foods are filled with heavily processed ingredients.
The cheap and easy access to this fast food are some of the many attractions to those that eat this type of food. How can a fast food burger be so cheap you ask? There are many reasons for this. Many chemicals are used to process the meat and some of them have even been found to damage DNA amongst other things (endalldisease n.d.). What really helped fast food to proliferate is the factory farming industry and at the same time fast food boom fueled the growth in factory farming. Animals unlucky enough to end up in a factory farm are injected with a slew of drugs ranging from antibiotics to anti-depressants.
Antibiotics are commonly mixed in with food and water and constantly given to the animals to increase growth rates. This has lead the evolution of antibiotic resistance bacteria, epically methicillin-resistant Staphylococcus aureus (MRSA) (Rinsky et al., 2013). MRSA causes skin abscesses and weakens the immune system to the point if left untreated death can occur. Recently the number of people who checked into hospitals with this has doubled. Doctors have found that many of the drugs normally used on MSRA are no longer working. This bacteria is spread from the animals to the workers and then into the rest of the public. As this over and miss use of antibiotics continues they will continue to become less or ineffective in treating humans who need them to get well (Rinsky et al., 2013).
I think this is a scary example of how societies eating habits can impact evolution and cause once easily treatable illnesses to become life threatening. I am sure the plants and animals we aim to control are also evolving in different ways. I can see the combined effect of all these changes having a very negative impact on overall human health.
Here is a great NPR segment entitled: “Modern Humans Still Evolving, and Faster Than Ever”. Here is the link to the page where you can read or listen to the story: http://www.npr.org/2013/09/27/226837803/modern-humans-still-evolving-and-faster-than-ever
Diet and Evolution[]
In addition to Nickele's statements regarding diet driving human evolution, it feels like all of America is collectively, overweight, sick and struggling.
Personal diet choice, particularly vegetarism is a point of interest regarding how our society and humans as a whole have evolved. People become vegetarian for many reasons; healthier lives, environmental footprints, animal ethics, etc. Health is a main reason that people go veg, and as you stated in your post and current research agrees that 70 percent of all diseases, including one-third of all cancers, are related to diet (Sabatet, 2003). Going vegetarian, and even better, vegan, can reduce the risk of a plethora of chronic degenerative diseases, such as obesity, high blood pressure, certain types of cancer and the list goes on and on! Yet, with all these benefits, one has to wonder after reading the article by Arjamaa and Vuorisalo (2010), does being a vegetarian contribute to a smaller brain size? Will vegetarians evolve slower or are they ahead of the game?
References[]
Arjamaa, O and Vuorisalo, T. 2010. Gene-culture co-evolution and human diet. American Scientist 98: 140 – 147.
Flatow, I. (Interviewer) & Hawks, J. (Interviewee). (2013). Modern Humans Still Evolving, and Faster Than Ever [Internet transcript]. Retrieved from NPR website: http://www.npr.org/2013/09/27/226837803/modern-humans-still-evolving-and-faster-than-ever
Sabaté, J. (2003). The contribution of vegetarian diets to health and disease: a paradigm shift?. The American journal of clinical nutrition, 78(3), 502S-507S. Stokel, K. (2011). The beneficial omega-6 fatty acid. Life Extension Magazine. Retrieved from http://www.lef.org/magazine/mag2011/jan2011_The-Beneficial-Omega-6-Fatty-Acid_02.htm
Corporate Accountability International. (n.d.) Co8untering fast foods health effects. Retrieved from http://www.stopcorporateabuse.org/countering-fast-foods-health-effects
Endalldisease (n.d.) McDonalds fast food: toxic ingredients include putty and cosmetic petrochemicals. Retrieved from http://www.endalldisease.com/mcdonalds-fast-food-toxic-ingredients-include-putty-and-cosmetic-pet...
Jeffery, R., French, S. (1998). Epidemic obesity in the United States: Are fast food and television viewing contributing? American Journal of Public Health, 88(2), 277-280.
Rinsky, J., Nadimpalli, M., Wing, S., Hall, D., Baron, D., Price, B., …, Heaney, C. (2013). Livestock-associated methicillin and multidrug resistant Staphylococcus aureus is present among industrial, not antibiotic-free livestock operation workers in North Carolina. PLoS ONE, 8(7), e67641. doi:10.1371/journal.pone.0067641
Said, S. (2013) Countries that consume the most fast food or junk food. Retrieved from http://www.therichest.com/expensive-lifestyle/location/countries-that-consume-the-most-fast-food-...