Keep Sharp: Build a Better Brain at Any Age

Book Preface

The brain is wider than the sky… [and]… deeper than the sea.
EMILY DICKINSON

Unlike most of my colleagues, I didn’t grow up with a deep-seated desire to be a doctor, let alone a brain surgeon. My earliest aspiration was to be a writer, likely triggered by a boyhood crush I had on a grade school English teacher. When I chose medicine, I was thirteen years old and my grandfather had just suered a stroke. We were very close, and witnessing his brain function change so quickly was jarring. He was suddenly unable to speak or write but seemed to understand what people said and could read without diculty. Simply put, he could receive verbal and written communication easily, but he could not respond in those same ways. It was the rst time I became fascinated by the intricate and mysterious functioning of the brain. I spent a lot of time at the hospital and was that annoying kid who asked the doctors a lot of questions. I felt very grown up as they patiently explained what had happened. I watched as those doctors were able to return my grandfather to good health after opening up his carotid artery to restore the blood ow to his brain and prevent future strokes. Having never spent much time with surgeons before then, I was hooked. I started reading everything I could about medicine and the human body. Before long, I was
xated on the brain, and specically memory. It still astonishes me that our memories—the very fabric of who we are—can be reduced to invisible neurochemical signals between tiny areas of the brain. For me, those early explorations into the world of brain biology were at once demystifying and magical.

Years later, when I was in medical school in the early 1990s, conventional wisdom was that brain cells, such as neurons, were incapable of regenerating. We were born with a xed set and that was it; throughout life, we’d slowly drain the cache (and accelerate that killing o with bad habits like drinking too much alcohol and smoking marijuana—the truth about that later). Perhaps it was the eternal optimist in me, but I never believed that our brain cells simply stopped growing and regenerating. After all, we continue to have novel thoughts, deep experiences, vivid memories, and new learning throughout our lives. It seemed to me that the brain wouldn’t just wither away unless it was no longer being used. By the time I nished my neurosurgery training in 2000, there was plenty of evidence that we could nurture the birth of new brain cells (called neurogenesis) and even increase the size of our brains. It was a staggeringly optimistic change in how we view the master control system of our bodies. Indeed, every day of your life, you can make your brain better, faster, tter, and, yes, sharper. I am convinced of that. (I’ll get to the bad habits later; they don’t necessarily kill brain cells, but when they are abused, they can alter the brain, especially its memory powers.)

Let me say at the outset: I am certainly a fan of excellent education, but this is not what Keep Sharp is all about. This book is less about improving intelligence or IQ and more about both propagating new brain cells and making the ones you have work more eciently. This isn’t so much about remembering a list of items, performing well on exams, or executing tasks adeptly (though all of those goals will be more achievable with a better brain). In Keep Sharp, you will learn to build a brain that connects patterns others might miss and helps you better navigate life. You will develop a brain able to toggle back and forth between short-term and long-term views of the world and, perhaps most important, a brain highly resilient in the face of life experiences that might be disabling to someone else. In this book, I will precisely dene resilience and teach you how to nurture it. Resilience has been a critical ingredient for my own personal growth.
Context matters when talking about something as important as the function or dysfunction of our brains, and our view of cognitive decline has changed dramatically over time. The history of documenting dementia dates back to at least 1550 BCE, when Egyptian doctors rst described the disorder in what’s known as the Ebers Papyrus, a 110-page scroll or manuscript that contains a record of ancient Egyptian medicine. But it was not until 1797 that the phenomenon was given a name, dementia, which literally means “out of one’s mind” in Latin. The term was coined by a French psychiatrist, Philippe Pinel, who is revered as the father of modern psychiatry for his eorts to push for a more humane approach to the care of psychiatric patients. When the word was
rst used, however, dementia referred to people with an intellectual decit (“abolition of thinking”) at any age. It was not until the end of the nineteenth century that the word was conned to people with a specic loss of cognitive ability. During that century, the British physician Dr. James Cowles Prichard also introduced the term senile dementia in his book, A Treatise on Insanity. The word senile, which means old, referred to any type of insanity that occurs in old people. Because memory loss is one of the most prominent symptoms of dementia, the word became mostly associated with old age.

For a long time, the elderly with dementia were believed to be cursed, or to have an infection like syphilis (because the symptoms of syphilis can be similar). So the word dementia was considered pejorative, used as an insult. In fact, when I rst told my kids I was writing this book, they asked if it was about dementors, the dark, soul-sucking creatures from Harry Potter. The idea that dementia, which is not a specic disease but a group of symptoms associated with memory loss and poor judgment, is sometimes thought of in such negative ways is worth addressing briey here.

It is true that scientists and doctors use the word clinically, and it is also true that patients and their loved ones don’t always know what to make of it, especially when they rst receive the diagnosis. It is too imprecise, for one thing. Dementia can be a spectrum, ranging from mild to severe, and some of the causes of dementia are entirely reversible. Alzheimer’s disease, which accounts for more than half the cases of dementia, gets nearly all the attention, and as a result, the terms dementia and Alzheimer’s are often used interchangeably. They shouldn’t be. The word dementia, however, is steeped in our common vernacular, and so is the association with Alzheimer’s disease. In this book, I use both terms with the hope that the conversation, and the words we use to describe the broad condition of cognitive decline, will shift in the future.

I believe there has been an overemphasis on Alzheimer’s disease as a way to talk about this broad condition, and it has further fueled a widespread sense of fear that memory loss is inevitable as we get older. Perfectly healthy people in their thirties and forties are alarmed about the implications of common memory lapses, like misplacing their keys or forgetting someone’s name. That is a misguided fear, and as you will learn, memory loss is not a preordained part of aging.

As I started traveling the world talking to people about this book, I realized something else extraordinary. According to an AARP survey of Americans aged thirty-four to seventy-ve, nearly everyone (93 percent) understands the vital importance of brain health, but those same people typically have no idea how to make their brains healthier or that achieving such a goal is even possible. Most believe this mysterious organ encased in bone is a black box of sorts, untouchable and incapable of being improved. Not true. The brain can be continuously and consistently enriched throughout your life no matter your age or access to resources. I have opened the black box and touched the human brain, and I will tell you all about those extraordinary experiences in this book. As a result of this training and decades of additional learning, I am more convinced than ever that the brain can be constructively changed—enhanced and ne-tuned. Just consider that. You probably think of your muscles that way —even your heart, which is a muscle. If you are reading this book, you are someone who is probably already proactive about your physical health. It is time to realize the same is possible with your brain. You can aect your brain’s thinking and memory far more than you realize or appreciate, and the vast majority of people haven’t even begun to try. Keep Sharp is going to help you design your own “sharp brain” program, which you can easily incorporate into your daily life. I have already done it myself, and I am excited to teach you to do it as well