Epidemics. This seems to be one of the media's favorite terms lately. Obesity is an epidemic. There were H1N1 and Avian flu scares. Even social traits like sadness and happiness are being talked about as transmittable 'symptoms' of social behavior. Overall, anything and everything can be contagious if we really think about it. But what I want to discuss here is a transition of epidemics and possible underlying causes that can be overlooked when dealing with particular diseases or sets of diseases.
Obesity is the epidemic of our generation. Never before has the body-mass index (BMI) of the human population ever gained such ground before. Obesity rates in the US rising upwards to one-third of the population and up, with many other developed nations catching up quickly. One in three seems ridiculously high. Back around the 1970s and earlier the rates sat steady around the 10% mark, and since then a steady rise pushed it up to the 30% mark. The interesting connection to make at this point is the change in smoking rates over the same time period. Back in 1970 smoking rates sat around the mid 40% mark and has now reached the mid 20% mark. If you look at the numbers carefully there is something in common between the two trends. Namely, the change in both of these rates is approximately 20%.
It would be too hasty to jump to the conclusion that smoking prevented obesity, or that smokers who quit end up getting obesity. The connection is easy enough to make considering how smoking is played up in the media as a way to stay thin. I'm sure there were even a few cigarette ads that used this strategy to appeal to its customer base. I think it is easy to dismiss this connection as a mere coincidence, however I will attempt to make the link anyway.
The backstory behind the rates of obesity is usually pointed towards the poor dieting habits of this generation. Things like fast-food are being blamed as a source of low-cost, high-calorie food. Other causes include saturated fats, carbohydrates, decreased plant-based consumption, and so on. All of these factors allow something like obesity to run rampant, but I still think the greatest factor is convenience. All of these cheap, bad foods are easily available. Fast-food, chips and pop are very easy to obtain. Easy access can provide reinforcement for addictive behavior. It doesn't help that our bodies feel good eating sugar, fat, and salt. The combination of the temporary boost in mood along with convenience is a potent mix.
During this rise of junk-food culture was a paralleled battle against tobacco. The dangers of smoking were starting to emerge and all sorts of warnings were being issued by the authorities. Gradually over time the connection between use of tobacco products and various types of diseases could no longer be denied, and eventually became accepted as a common truth in the public eye. People who smoked had to balance the way it makes them feel against the potential downfalls. One interesting trend in the medical area that has recently emerged surrounds the addicting element of cigarettes known as nicotine. It has been found that acetylcholine (ACh) is released from the vagus nerve during times of stress to help reduce inflammation. One of the last resort treatments for depression involve stimulating the vagus nerve directly. Nicotine mimics ACh since they both bind to some of the same receptors in the body. In fact ACh receptors were first discovered because of the activity of nicotine, and the first receptors were named nicotinic receptors. Though smoking causes a sensation of relaxation and creates a calming effect no one would have known that they were self-medicating the whole time.
The common theme between the two habits of overeating and smoking is that of mood adjustment. Smoking was unknowingly changing a host of physiological functions in side the body to minimize inflammation and suppress any feelings of depression that may have emerged keeping them hidden. The same can be said for obesity. One of the main effects of becoming overweight is the risk of developing Type II diabetes. Eating high amounts of sugar and fat lead to insulin resistance and elevated blood sugar as a result. Insulin normally antagonizes another hormone called cortisol. Cortisol is released during stress to increase the amount of blood sugar and decrease inflammation. With increased insulin resistance this relationship between insulin and cortisol become imbalanced. There is an elevated level of cortisol and simultaneously elevated blood sugar. Once again, a stress related mechanism is at the forefront of the complications of a simple habit, eating unhealthy tasty food.
It seems like the correlated increase in obesity and decrease in smoking rates are somehow joined by this need to manage stress. Both of these phenomenon are mainly only prevalent in developed nations and less so with underdeveloped parts of the world. The main stressors involved in developed societies manifest themselves through urbanization. Massive amounts of people in a high density creates stressful situations through its level of complexity and subsequent unpredictability. As a result, I think people need to find a way to cope. Originally this was found through tobacco. Now it's a burger, a side of fries, and a fizzy drink.
I believe that there is a stronger underlying pressure that isn't being addressed that involves the stability of the people and the overarching stress of the population. Something beneath the surface is holding constant, pressuring the people to make certain choices to protect their sanity. Smoking and overeating aren't the only addictions available. Shopping, gambling, drinking, sex and other drugs are playing their part as well. The question is, will this problem ever be properly resolved? Or will another epidemic spring up once obesity is brought back under control?