Brain Food: The Surprising Science of Eating for Cognitive Power

A few years ago, I delivered the keynote at an international conference on the prevention of Alzheimer’s disease. It was a beautiful sunny day in Italy, the lecture hall brimming with doctors, students, and laymen, all eager to hear the latest on pharmacological treatments for Alzheimer’s.

I was much less eager to be the bearer of bad news. Unfortunately, current medications for Alzheimer’s lessen symptoms for a limited amount of time but cannot stop the damage that aging and disease cause to brain cells. A new generation of disease-modifying drugs is under development, but clinical trials have yielded mostly disappointing results so far, confirming what everyone knew: there is no cure in sight.

At which point someone in the audience asked: “How about olive oil?”

My neuroscience-trained brain was baffled. Olive oil?

Olive oil was not in any of my research proposals, or in any way part of my education. I got my PhD in neuroscience and nuclear medicine to focus on the genetic aspects of the disease, motivated in part by seeing its devastating effects on my immediate family. My work for the last fifteen years has been focused on the early detection of Alzheimer’s. Specifically, in my research I use brain imaging techniques, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), to look at people’s brains in relationship to their genetic backgrounds, and in doing so, learn about their likelihood of developing disease.

This work led me to direct the Family History of Alzheimer’s research program at the NYU School of Medicine back in 2009. The program focuses on the children and family members of Alzheimer’s patients. Everyone there has broadly the same concern: “Am I at risk for Alzheimer’s and what can I do to make sure I don’t get it?”

Over the years, I experienced a change in the kinds of questions I was asked by our patients, much like the olive oil question at the conference. Beyond the discussions about genes and DNA, sooner or later the conversation turned to food: “What should I eat to keep my brain healthy?”

While all my research draws on my education as an adult, everything I associate with food comes from my upbringing in Florence, Italy. Back in my hometown, I developed a heartfelt appreciation for wholesome, healthy food from a very young age, which I took for granted until I moved to the United States to study for my PhD. I had not anticipated the challenge of finding a flavorful tomato or the artery-clogging danger hidden within a seemingly innocent chocolate chip cookie. As I struggled with my own diet in my new environment, I learned from my research that I was not alone. By their own accounts, more than half of my study participants reported only trace amounts of vegetables and fruits in their diets.

Little by little, it became clear that I wasn’t just far from home. I was also far from the original theses about the genetic aspects of dementia. In fact, it turns out that the role of genetics in Alzheimer’s, and dementia in general, is not as major as we previously thought. While some patients carry aggressive genetic mutations that cause dementia, for the vast majority of the population, risk is influenced by a variety of medical and lifestyle factors—including a person’s diet. When my research revealed how important, and how oddly neglected, diet and nutrition had been in the field, I went back to school and completed a third degree in integrative nutrition. I drew upon that and other work to found the Nutrition & Brain Fitness Lab at NYU, with the goal of identifying lifestyle factors that support the brain’s health, safeguarding it against dementia. A few years later, I initiated the Brain Nutrition coursework and began teaching at the NYU Steinhardt School’s Department of Nutrition and Food Studies. Around the same time, I moved to Weill Cornell Medical College, where I have the honor of serving as the Associate Director of the first Alzheimer’s Prevention Clinic in the country. The clinic’s innovative approach includes pharmaceutical as well as behavioral interventions aimed at improving both medical status and lifestyle choices in an Alzheimer’s-preventative way. Diet and nutrition are a big part of the practice. Altogether, this work has led me to dive headfirst into the complex relationship between our brains and the foods we eat, and to educate the public as to how to eat healthfully for their brains.

As with anyone who has ever gone down a dietary path toward optimal nutrition, I quickly realized that the available advice was often conflicting and incoherent. But as a scientist, I was above all surprised at the volume and effect of pseudo-scientific information available on the Internet, especially in comparison with how little had been published with the rigor of peer-reviewed medical journals.

We’ve heard a lot about what is and isn’t good for our brains. For example, many of us have recently become aware of an American gluten panic. But only a few years ago, grains were considered the epitome of eating healthy—and people were terrified of eating fatty foods. The problem is that while many of the recommendations you can find online promote a scientific worldview, very few have been substantiated by sound research. The Internet and media in particular have a tendency to make broad extrapolations on limited findings and sensationalize everything. For instance, at least once a week someone will ask my opinion on the latest “miracle drug” for Alzheimer’s. I’ll look up the study. More often than not, it’s true that the drug worked . . . but in a population of ten mice. So that’s great news if you are one of those ten mice. Whether or not those findings are relevant to people is a whole different story.

This is where scientific literacy comes into play. Which sources of information are the most credible? How can we know if the study we heard about in the evening news is worth acting upon?

While sound scientific research is more limited than Internet blogs, results do prove to be consistent. A new generation of studies has begun to identify which nutrients are particularly helpful in enabling our brains to work at the max, as well as protecting them as we age, thereby granting us continued mental strength over the course of a lifetime. At the same time, we are also learning which nutrients are harmful to the brain, negatively affecting our cognitive abilities and increasing the risk of mental deterioration. This includes my personal experience accumulated over years of hands-on research regarding the important interactions among genetics, nutrition, and lifestyle.

What’s important to note is that I’m not just presenting the results of my own research, but rather the analysis of hundreds of scientists who have been studying the relationship between the foods we eat and the health of our brains over the decades. I’m hoping to make clear that science is never a result of one person’s opinion, but always involves a collective of doctors, scientists, and even you, the population itself, in an ongoing, educational exchange that unfolds over time. Thanks to this worldwide dedication, we challenge one another to get to the bottom of those things we’re most determined to resolve. In fact, the beauty of science should be strength in numbers.

The danger of looking at isolated papers is that you might find that what appears to be fact in one study is proven wrong in the next. One day you read that “according to science” you must avoid cholesterol at all costs. Then you turn around to find another equally “scientific” explaining the role cholesterol plays in supporting a healthy brain. How can both things be true?

Ultimately, no single study is perfect. One can never be absolutely sure that its findings are valid and applicable to the population at large. We need to look at a bigger picture. The more an independent study replicates a specific finding, and insists upon applying a wide range of methods to an equally wide number of patients, the more likely that the finding is actually true and applicable to everyone.

Make no mistake. There is a bottom line when it comes to what’s good for your brain and what’s not. In Brain Food, I draw on my background as a neuroscientist to build a neurological and nutritional framework around the ways that food is specifically vital in promoting optimal brain health. In the pages that follow, we will get down to the details of what science has discovered so far by exploring neuro-nutrition, or nutrition for the brain. We’ll look at how food breaks down into nutrients, and to what degree these nutrients feed our brains. We’ll talk about how the brain actually works, and the specific influence diet has on our cognitive performance. But mostly, we’ll see how the human brain has its own unique diet, different from that of the rest of the body. Just as we would eat differently to slim down than to train for a triathlon, when optimizing for long-term cognitive health, the brain has its own demands. As it turns out, our future lies in our own hands—and what’s on our menu.