By Olaf Schulz-Lobeck
To support people thriving successfully in modern times via good health, it is essential to understand how the last century impacted us. A lot happened!
One hundred years is too short for an evolutionary selection process via genetic change transformations, so we must understand that changes within this period of time are “simply the developmental responses of organisms to changed conditions.”
Stephen Stearns, a professor of ecology and evolutionary biology at Yale University, highlights that evolution has shaped these developmental programs that respond flexibly to environmental changes. And though it may seem that natural selection does not affect humans the way it did thousands of years ago, such evolutionary mechanisms still play a role in shaping humans as a species.
Humans are getting taller, they are also fatter than ever and live longer than at any time in history.
A recent British study, published by the Institute for the study of Labor (IZA) in Bonn, Germany, showed that men in the United Kingdom have grown by 4 inches (10.16 cm) on average since the turn of the 20th century.
In the study of British recruits, the average high of British men, who had an average age of 20, was about 168 cm at the turn of the century, whereas now they stand on average at about 178 cm. The increase can be attributed to imporved nutrition, health services, and hygiene, said the reserachers of the University of Essex in Colchester (UK).
And even in some of those countries where the average high has been rising, the increase has not been uniform. For instance, people from former East Germany are still catching up height-wise with former West Germans after years of communist rule, said Barry Bogin, a professor of biological anthropology at Loughborough University (UK). And in some non-Western countries that have been plagued by war, disease, and other serious problems, average high has decreased at one point in time.
Another example was a decline in the mean height among blacks in South Africa between the end of the 19th century and 1970. Barry Bogin emphasized this phenomenon in one of his studies published in the Nestle Nutrition Institute workshop series in 2013. He explained that the decline was likely related to the worsening of socio-economic conditions before and during apartheid.
The key causes are increased consumption of energy-dense foods that are high in saturated fats and sugars and reduced physical activity
This rising epidemic reflects the profound changes in society and behavioral patterns of communities over recent decades. While genes are important in determining a person’s susceptibility to weight gain, energy balance is determined by calorie intake and physical activity. Factors such as societal changes and worldwide nutrition transition are driving the obesity epidemic. Economic growth, modernization, urbanization, and globalization of food markets are just some of the forces thought to underline the epidemic.
As incomes rise and populations become more urban, diets have changed. Food high in complex carbohydrates have replaced more varied diets with a higher proportion of fats, saturated fats, and sugar. At the same time, large shifts toward less physically demanding work have been observed worldwide. Moves toward less physical activity are also found in the increasing use of automated transport, technology in the home, and more passive hobbies.
At F.X. Mayr, we are observing a fundamental change caused by the demands of our performance-driven society since the 21st century. Wealthy people, who in the past were likely overweight due to not having to physically work as hard, are getting slimmer, more active, and healthier. In contrast, poorer people, who in the past were slimmer due to doing more physical work, are getting fatter and less healthy. Reasons can be traced to less access to education, less physical work, the oversupply of cheap, readymade products, cheap and fast food, and a culture of 24/7 food availability.
Although factors such as significant advances in medicine, better sanitation, and access to clean water have greatly reduced mortality rates from infectious disease, the death from degenerative diseases such as Alzheimer’s, Parkinson’s, heart diseases, and cancer are on the rise. In other words, people are living longer and dying from different diseases than they did in the past.
Access to healthcare is a very big factor. For older people, given they are more prone to illness than young people, being able to see the doctor is very important. This means being able to afford visits to the doctor and being able to actually get into the doctor’s office.
Another substantial factor in determining lifespan is family or community. Regular contact with loved ones is a huge plus in extending people’s lives. If someone falls or has a health crisis, they’re more likely to be found in time if they have people around them. And, perhaps a bit more sweetly, people just tend to have better health if they’re socializing with people. Why this is true is up for debate, but lots of studies support the basic idea. One study from John Hopkins Medicine even argues that younger people who assist older people also see some health benefits.
In what might be the biggest placebo effect of them all, having a sense of purpose is a big plus. Having some goals and responsibilities drives a lot of people to live years longer than people who feel lost or unimportant. This might be a career goal or a hobby, or even taking care of a pet. The big thing is that in countries with high life expectancy, old people are more likely to feel engaged. This can be a cultural difference, or it can be geographical. Old people are more likely to do things if they can physically get around, for example.
“There is some fear out there that an esoteric cabal of scientists in white coats is going to take over the future of evolution with genetic engineering,” according to Professor Stearns. “Whether we want to or not, we have already changed our future course of evolution, and it is not being done by some small group of people. Is it being done as a byproduct of thousands of daily decisions that are implemented with technology and culture.”