the brain benefits from being used
i just read this article from the NYTimes magazine on weight lifting rats. the article summarizes some interesting research being done on whether bulking up impacts the brain in a positive way. it has already been shown that running and other aerobic exercise leads to neurogenesis - ie growing new neurons - in parts of the brain involved with thinking and memory. scientists think this increased growth is probably due to increased blood flow to the brain, or at least that’s what they posit. no one actually knows why.
what’s new here is the research showing that weight lifting - as modeled by brazilian rats running up ladders with weights strapped to their tails and japanese rats running on weight-loaded wheels so they bulk up their little rat quads - has the same effect. rats with extra muscle at the ends of the studies had more of a chemical called BDNF (brain-derived neurotrophic factor) in their brains. and BDNF is known to stimulate the growth of neurons and and the underlying gene activity such growth requires, genes being the computer code of sorts behind the constant building of the body’s new parts.
i hope more research like this comes along with more sophisticated hypotheses and better evidence as to why exercise has such strong effects on brain plasticity. that said, the conclusion of this research seems like a bit of common sense. while there is always benefit to better understanding things like the link between muscle mass and BDNF, because this teaches us a little more about how the body works, there is already a lot of evidence for the impact of exercise on the brain, in particular good research showing that exercise slows cognitive decline. most of that research is on alzheimer’s disease, the most common cause of dementia. while there is no cure for alzheimer’s, regular exercise slows it down. and actually, so do friends. people with strong social networks fare better than those without.
if you’re unsure of what alzheimer’s is, you’re not alone. really no one else does either, but here is my basic explanation. for reasons we do not yet understand, alzheimer’s is the filling up of the brain with junk proteins that get in the way of information transfer between neurons. when the information flow stops the neurons die and the brain shrinks. when you look at an alzheimer’s patient’s brain on a CT scan compared with a normal brain, the alzheimer’s brain is strikingly shrunken with big empty fluid pockets - everything black is fluid - in the middle and around the sides.
but back to exercise. the applied principle of all this - meaning like, how does this research relate to me today - is what i think is most useful. when you don’t work out, your muscles shrink. and when you don’t read or study or talk to people, well, simply put your thoughts shrink - the arc of things you think about and say becomes a little narrower. the human brain has 100 billion neurons and a 100 trillion points of connection with each other. neurons are living cells that talk to each other through little pulses of chemicals between them, forming thoughts and memories and work patterns through the brain. if your body is healthy and active and your blood is relatively clean and your heart is strong and there are friends and laughter and love in your life, and you maintain a healthy dose of daily challenges for your brain to puzzle through, it makes sense that your neurons are better off too.
which is why this article’s concluding sentence, “the brain benefits from being used,” makes me smile. in yoga the mind and the body are one. in western culture we’ve separated the two and it’s considered novel research to show that what’s good for one is good for the other.