Theodosius Dobzhansky, evolutionary biologist, said, “Nothing in biology makes sense, except in the light of evolution.” What did he mean by this? All organisms adapted to thrive and survive in a particular environment, if that environment changes faster than the organism can adapt, mismatch occurs. This fundamental biology principle applies as much to humans as it applies to any other organism in nature.
For 66,000 generations, humans ate primarily meat, fish, fruits and vegetables, nuts and seeds, and some starchy plants. Our hunter-gatherer ancestors were much more physically active, they didn’t sit for long periods, they lived in sync with the natural rhythms of light and dark, in direct contact with nature, and in close social groups. Our ancestors were leaner, fitter, stronger and free of chronic inflammatory diseases. You could argue that they were superior to us in every measure of health and fitness, from body mass index (BMI) to blood pressure, from insulin sensitivity to oxygen consumption, from vision to bone density.
Contrast this with today's industrialised world, when obesity and diabetes combined affect a billion people worldwide. Cardiovascular diseases (CVDs) are the number one cause of death globally, an estimated 17.7 million people died from CVDs in 2015, representing 31% of all global deaths. Of these deaths, an estimated 7.4 million were due to coronary heart disease and 6.7 million were due to stroke. "Most cardiovascular diseases can be prevented by addressing behavioural risk factors such as smoking, unhealthy diet and obesity, physical inactivity and harmful use of alcohol using population-wide strategies." (World Health Organisation)
Cancer is the second leading cause of death globally, and was responsible for 8.8 million deaths in 2015. Globally, nearly 1 in 6 deaths is due to cancer. Around one third of deaths from cancer are due to the 5 leading behavioral and dietary risks: high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco use, and alcohol use. The economic impact of cancer is significant and is increasing. The total annual economic cost of cancer in 2010 was estimated at approximately US$ 1.16 trillion (World Health Organisation)
Billions of people suffer with high blood pressure. Dementia rates are increasing at a rapid rate along with autoimmune disease. There were an estimated 46.8 million people worldwide living with dementia in 2015 and this number is believed to be close to 50 million people in 2017. This number will almost double every 20 years, reaching 75 million in 2030 and 131.5 million in 2050 (The Global Voice on Dementia). Just think about that for a second. It's scary to think that more than 80 distinct autoimmune diseases have already been identified, and several new ones are being identified each year (Autoimmunity and the Gut).
Obesity in Australia is one of the biggest public health challenges facing the population. More than half of the adult population has a body weight that poses serious health risks. More than 60% of Australian adults are obese and almost 10% are severely obese. At least a quarter of Australian children and adolescents are obese or overweight - (Australias Obesity Statistics 2017)
The US and England is no better off, In the 2016 survey, it found that 26.2% of adults in England are obese and a further 35.2% are overweight, making a total of 61.4% who are either overweight or obese (Obesity Statistics). In 2013 the Organisation for Economic Co-operation and Development (OECD) found that 57.6% of American citizens were overweight or obese. The organization estimates that 3/4 of the American population will likely be overweight or obese by 2020 (The 10 Healthiest States in America). The latest figures from the CDC as of 2014 show that more than one-third (36.5%) of U.S. adults age 20 and older ( Adult Obesity Facts | Data | Adult | Obesity | DNPAO | CDC) and 17% of children and adolescents aged 2–19 years were obese (Childhood Obesity Facts | Child | Data | Obesity | DNPAO | CDC).
This is only scratching the surface of this serious global health epedemic we are faced with. The number of deaths caused by obesity and the impacts that autoimmune disease are having on our health are growing every day along with the phenomenal economic costs to society.
So what happened? Where did is all go wrong? What transformed us from physically health, vital people, free of chronic disease, to a sick, fat and unhealthy people?
There were two main blows that drastically shaped the environment that we currently live in and we talk more about them in the following blog posts:
Sick, Fat and Unhealthy: Part 3: The Industrial Revolution