Keeping fit and eating healthy is as good for your brain as it is for your body and exercise can help keep the worries of the modern world at bay. Carl Dixon looks at how
There is an underlying prescription to being human. As a species we are intelligent, omnivorous, tribal and highly resourceful and it was these attributes have allowed us to dominate the planet. Humanoid history goes back millions of years, and our particular species Homo sapiens spread from Africa approximately 50,000 thousand years ago.
Many evolutionary psychologists argue that we have not substantially changed, either physically or psychologically, since then.
Deep in our DNA, we remain tribal hunter gatherers. Although the characteristics of our species may be largely unaltered, society has changed beyond all recognition, and this mismatch may be responsible for many of the problems that plague us.
We now have the dangerous luxury of being safe in our natural environment and we can be passive, sedentary and unchallenged if we choose to be.
But can we really remove all the fundamental physical, psychological and societal conditions that moulded us as a species and continue to thrive?
John Ratey is an associate clinical professor of psychiatry at Harvard Medical School and is the co-author of GoWild: Free Your Body and Mind from the Afflictions of Civilisation.
Pulling on disparate threads, including how we eat, sleep, move and how we connect to each other and nature, he argues that we need to return to a more natural way of living that is more in tune with our evolutionary past. We are designed to be wild and by living tamely, we make ourselves sick and unhappy.
“The single greatest change in human history was the change from hunter-gatherer to agricultural societies,” he says.
“We were moving 10-14 miles a day when hunting and foraging. Dense packets of storable starch from agriculture allowed sedentary lives. Now we have an overabundance of carbohydrates, but we are programmed to store food as fat and to not waste calories by being physically active unless we have to. The result is obesity.
“Our addiction to carbs causes huge problems because too much glucose is highly toxic and type 2 diabetes is a screaming, wailing siren of warning to our society.”
For Ratey, health begins with movement. Some animals are specialists, but humans have been described as the Swiss Army knife of motion. We are probably the best endurance runners on the planet, but we are also ballet dancers, long distance swimmers and powerlifters.
Computers can play chess, but building a computer that can manipulate a chess piece with the dexterity of a six-year-old, defeats us. Only a large, highly sophisticated brain is powerful enough to coordinate our complex movements. Physical activity is an integral part of who we are and Ratey argues that it is a key component of human happiness.
In the Naperville High School in Chicago, which Ratey has written about extensively in his book Spark, The Science of Exercise, a dedicated daily physical exercise programme, resulted in dramatic improvements in academic performance.
“Despite a daily PE programme, the kids were not getting any healthier,” he says.
The PE teacher decided to give kids good grades if they stayed within certain heart rate zones, rather than just competing with each other. They were now competing with themselves and results were based on effort. Three percent of the 19,000 kids in that school district were overweight, the national average in the US at that time was 33%.
What was more fascinating was that when 99% of the children in that school district took the International Mathematics and Science Study (TIMSS), they came first in the world in science and sixth in math.
Exercise impacts in particular on the prefrontal cortex, it prepares the brain for learning.”
It now seems that exercise places demands on the brain, which releases certain chemicals in response. These chemicals provide the ideal environment for the brain to grow new cells, make more connections and flourish. By contrast a sedentary lifestyle is associated with lower cognitive skills and may contribute to mental decline in later life.
“I am just back from Japan and they are starting to focus on this,” he says. “They are starting to see that physical exercise makes children better. I think we are on the cusp of paying attention and making changes.”
Ratey notes that the varied sleeping patterns of teenagers, adults and older people ensured that someone was always awake to look out for predators. In most cultures, where everyone sleeps together in one big family group, a young child sleeping alone is considered child abuse. This ties in to another over-arching concept, which is the importance of community.
“It is the one chapter of the book which should have been longer,” Ratey admits.
“There is fantastic data coming from Harvard and Stanford that being in contact with other people helps with cognitive decline. We are also beginning to understand the neurobiology of mindfulness and how the different brain networks get activated and interact and how getting stuck in one network can lead to depression and anxiety.”
It is common in western culture to assume, despite considerable evidence to the contrary, that we are more evolved than our ancestors, that there has been a steady progression from primitive early humans hiding in caves, through fire making, agricultural and industrial revolution and finally onto abstract art, out of season avocados and space exploration.
2,500 years ago Hippocrates wrote: “All people in a bad mood should go for a walk, and if it does not improve, walk again.”
His words speak to a universal human experience and his words were just as relevant for our recent hunter-gatherer ancestors as they are for us.
It may seem counterintuitive to work backwards to solve modern problems, but researchers are finding that humans respond well when they incorporate elements from our evolutionary past — examples including forest bathing, barefoot running, paleo diet and periodic fasting-into modern life.
Nature, community, diet and movement are the fundamental building blocks of our species, and the mechanism by which natural selection sculpted our humanity over millennia.
Despite the many benefits provided by modern society, there is evidence to suggest that we cannot erode the fundamental building blocks of our species and still thrive. Depression, obesity and anxiety represent a huge challenge to modern, western culture.
“The crucial elements are physical health and community and connection with nature,” Ratey says.
“Try not to get too obsessed with the different food systems. A paleo-type diet works. Be reasonable with carbs, don’t eat processed foods and eat lots of meat and vegetables, you don’t need to go hard core and stop showering. Running in nature is better for you than running on a treadmill. Get enough sleep. Stay connected to friends, family and community. Meet people in person rather than online. There is a worry that the ease with which we live may overwhelm future generations and we need robust, adaptable children. Don’t raise soft children in a bubble. There is a book entitled The Wisdom of the Skinned Knee, I think that title says a lot.”
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