Is the Disconnect between Biology and Culture making you Ill? Part One: Evolutionary Medicine.

EvMedConstruct_0

Part One: Background

Over the winter, rather disgusted at the weight that I put on over the past 20 years, I decided to do something about it. Complaining was easy, but taking steps to improve my health also proved to be quite easy as well.

About 25 years ago, I was diagnosed with metabolic syndrome, and faced all the precautions that came along with it. A change in diet (which lasted about a week) and a suggestion for getting more exercise (which lasted less than a week). Fast-forward to 2015 and physician predictions of insulin and hypertension medicine, a statin, and further complications.

The chief difference between 25 years ago and today is that I was not a Ph.D. medical scientist then, and I had never heard of metabolic syndrome when I received my diagnosis. Until five years ago, I thought I was the only one who thought that many of the issues Americans deal with today were the result of a disconnect between evolution and our modern, sedentary, junk-food-filled lives.

Today, I study a number of medical subjects, including evolutionary medicine. This has completely changed how I look at nutrition, exercise, stress, and much of modern life. When I fall ill (admittedly rare), like you, I call my physician. The difference perhaps is that I have a pretty good understanding of how disease processes work. Although my area of expertise is environmental health and infectious disease, I have a pretty good grasp of how chronic conditions associated with aging affect us. As we grow older, contagious diseases that were once the bane of society have mostly been dealt with (of course with the anti-vaccination movement they are making a comeback), and with the exception of emerging infections like Lyme and other zoonosis (think Ebola, Hanta, and any one of a dozen encephalitis infections), those of us in midlife are left to contend with conditions that seem to strike in our 30s and 40s.

Complex Conditions, or a Single Condition Expressed Differently?

Complex conditions like type-two diabetes, and single diagnosis like hypertension, dyslipidemia, gout, irritable bowel syndrome, asthma, anxiety, depression, acid-reflux, even some cancers have long been understood to be associated with aging, but what if these are all the same inflammatory condition, expressed differently, and identified by their most prominent symptom? What if, certainly not all, but a large percentage of these chronic conditions might be directly associated with the changes in behavior, diet, and activities our species continues to undergo? Would it be possible to reverse at least some of these conditions?

The emerging science of evolutionary medicine is giving us a whole new look at what was once perceived as the inevitable, often genetic or merely age-related, illnesses that we would all face sooner or later. As it turns out, this may not be true. When we consider that biologically and physiologically at least, the human form has changed little (anthropologist argue not at all) over the past 70,000 to 80,000 years or about 4,000 generations. Many paleoanthropologists have suggested that, as a species with unique traits, humans have changed very little since our hunter-gatherer ancestors. Over the past 1500 years, we have experienced significant changes culturally; in the past 150 years these cultural changes have increased drastically. Life-style changes have taken place in how we live, what we do, how we move, and what we eat. These changes may be at the root of the drastic increases in many chronic (and mental health) diseases.

By examining the human physiology through the lens of evolutionary medicine, we can witness the cultural changes of the past 30 generations. Except in our biology. Evolutionary biologists point to the increases in chronic conditions as the failure of our biology to contend with the environments we have created. These conditions, often stemming from sedentary lifestyle, poor diet, or a combination, emerge because our physiology is simply not adapted to this modern environment. Homo sapiens did not evolve to consume large quantities of processed foods, sugars, high fructose corn syrup, or partially hydrogenated processed plant oils. These mismatch diseases can be understood as the result of non-adaptability to the modern world.

Today, the average American eats a lot of carbohydrates in the form of sugar, either from sugar cane, sugar beets, or chemically created sweeteners like high fructose corn syrup. This dense calorie intake of carbohydrates in the form of high starch content, combined with physical inactivity, has led to problems like chronic heart disease, type-two diabetes, and metabolic syndrome. Modern Americans have an almost unrestricted access to sweet foods; we crave sweetness, but this is a yearning based on a time when nearly all foods were naturally unsweetened. Our biological systems evolved over tens of thousands of years to crave the small amount of sugar from fruit (and occasionally honey if we endured the stings), and since the discovery of cane sugar and other sweeteners, the foods we eat have been getting progressively sweeter. Yet despite the easy caloric access, the types of calories in the meals we eat today are much less healthy than the foods our ancestors consumed just a few thousand years ago. Simply put, modern culture has evolved tens of thousands of times faster than biology, and the combination of sedentary life, sweetened food, and the easy access to simple carbohydrates like starch has created a ticking bomb.

If we continue to drastically increase our caloric intake, while significantly decreasing physical activity, the obvious result is a metabolic inequality that, just a few thousand years ago, was simply not possible. Our pancreas, capable of producing plenty of insulin when the sweetest foods we consumed were carrots and occasionally honey, are simply unable to handle the influx of sugar-sweetened everything that has become a staple for many Americans. If the pancreas cannot produce enough insulin to process the sugar and starches we consume, we can develop type-2 diabetes or metabolic syndrome; other physiological systems are also ill-equipped to handle this modern lifestyle, giving rise to a number of other chronic ailments ranging from autoimmune disorders, obesity, osteoporosis, impacted wisdom teeth, and a growing number of infectious disease agents are being strongly associated with our modern lifestyle.

In Part Two: Under Stress and Under-stressing the Immune System

 

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