We are in the midst of the greatest revolution the biomedical sciences have ever seen. Recent progress has made it possible for us to soon move past the one size fits all approach to medicine to an age of personalized medicine and precision therapies. This will have a dramatic impact on human longevity, allowing us to live much longer and healthier lives.
But what we might be creating by adding years of life is living prisons for decaying minds. The afflictions of the body are low hanging fruit, the complexity inherent to the brain and what it would take to figure out what goes wrong with it are many orders of magnitude greater. As science continues to take bold leaps forward it may soon leave us with an epidemic of rotting brains in healthy bodies.
Once you turn about twenty, for reasons we can’t properly explain, neurons in your brain start to die. Unlike other cells, neurons don’t grow back. But there are a hundred million neurons in your head with one hundred trillion connections between them, so you don’t notice when a few go.
But over time that damage accumulates. For some it happens faster than others. When damage crosses a certain threshold that death becomes visible as things in the body start going wrong, we call these things symptoms of disease. For example, once 50-80% of the dopamine producing neurons in an area of the brain called the substantia nigra die, people start to experience the tremor and rigidity we call Parkinson’s disease.
But it’s not like anything really changes before or after that threshold is crossed, we just give it the name disease because now symptoms of that cell death are visible, but what led to it is usually decades of accumulated degeneration that doesn’t stop.
And it happens to everyone throughout their life, even people who seem healthy accumulate damage in their brain that eventually leads to cognitive decline. As we age the brain also loses some of its plasticity as there are fewer neurons left to form new connections which is why older people have a harder time learning new skills.
Nothing has been proven to stop or even slow neurodegeneration. There are things that speed it up, like genetic mutations, poor nutrition, slothful lifestyles, and exposure to toxins, but nothing to slow or stop it. If we live long enough we will all suffer from neurodegenerative disorders.
Over the past year I have been visiting neuroscience labs across the world in an attempt to figure out the neurodegeneration going on in my own head. To date I have spoken at length with over fifty experts who spend their days on the frontiers of neuroscience and biomedical research; men and women teasing apart the smallest details of our biology and that 3 pound lump of goo between your ears that is responsible for everything you do, everything you feel, and everything you are. When I meet them I mainly ask them about their research, but I also try to get their sense of where we are in our understanding of the brain and where we’re going.
One question I often pose is – say perfect knowledge of the human brain is a 100 yard race, how far have we collectively gone in this race? The consensus from those I have talked to so far is that we are right around the 10 yard mark.
Trying to wrap your head around why the brain is such a difficult puzzle can be a little mind numbing. To master it not only would we need a map of the 100 billion neurons that make up each human brain and the 100 trillion connections between them and how those connections change from moment-to-moment, but we would also need a much better understanding of emerging disciplines like genomics, pharmacogenomics, transcriptomics, and proteomics to name a few.
However there is good news as most of the scientists I spoke to acknowledge that almost all of those 10 yards have been crossed since the turn of the century, and the pace of progress is itself accelerating. Many of the people I met are in fields that didn’t even exist a few decades ago: brain stimulation, stem cell research, tissue engineering and genetic modification therapies were science fiction for my parents’ generation. What’s more, the introduction of big data and artificial intelligence will further quicken our stride and get us even closer to understanding our brains, how they develop, how they interact with the world, and all that goes wrong along the way.
But it requires work, progress does not just happen, it is the result of human labor and human ingenuity and these scientists and researchers and doctors and nurses and everyone involved in health care need money, time and resources to continue pushing the science forward.
If you want to play a part in stopping neurodegeneration consider giving to one of the Parkinson’s disease charities listed below. Parkinson’s disease is likely to be one of the first neurodegenerative disorders that we figure out. If we do, not only will it have implications for other brain diseases, but everyone who experiences neurodegeneration. (That includes you!)