A new book by Dr. Bonnie Kaplan and Dr. Julia Rucklidge shows that what we eat affects our mental health.
In April 2021, a book entitled The Better Brain was published by Houghton Mifflin Harcourt. This groundbreaking book by researchers Dr. Bonnie Kaplan and Dr. Julia Rucklidge details the studies showing that what we eat affects our mental health. Psychologist and Aleteia contributor Jim Schroeder sat down with Dr. Kaplan to talk about her new book and why we should all be invested in the research and recommendations behind it.
Dr. Schroeder:You have just come out with a new book on nutrition and health, but when I look in the bookstore, I see lots of books on nutrition and health. Why did you write another one?
Dr. Kaplan: There are many layers to this answer. First, most of the previous books focused on the relationship between nutrition and physical health, such as bone and muscle development. While important, they neglect the proven link between what we eat and our brain health. Second, many of these books, although maybe well-composed, aren’t written by the researchers who actually investigate these links. We felt that the general public deserved to hear from those who actually do the studies, not just report on them. And finally, prior books tend to give advice about how and what to eat. But I know I am not alone in saying that if you tell me what to do, but don’t tell me why, I am less likely to do it. Our book is an attempt to provide the how, what, and why.
Dr. S:Throughout the book you say that there should be more education about this topic. Could you give us a little summary of what you think children in elementary school should learn about nutrition and their brains?
Dr. K: Well, what I think we need to start with is teaching our children that the brain is the most metabolically active organ in the body. Although the brain is only about 2% of our body weight, it utilizes a minimum of 20% (and some believe upwards of 40%) of the oxygen and nutrients available; meanwhile, 1/6 of the blood flowing through our body at any given time is in our brain. In other words, the brain is a needy, greedy organ. Kids are taught from an early age that food is important for their bodies, but rarely are they taught it is important for their brains. And thus, they wouldn’t even begin to consider that it is important for their mental health.
Dr. S:Would you please explain the difference between macronutrients and micronutrients, and why you always talk about the micros?
Dr. K: Macronutrients are major categories of food such as proteins, fats, and carbohydrates. Few in North America are lacking in these categories. But micronutrients, for purposes of discussion here, are generally thought of as vitamins, minerals, and essential fatty-acids. Many people in North America are significantly deficient in micronutrients, which unfortunately is linked to many problems with brain functioning and mental health.
Dr. S:So which will I find in potato chips? How about Pop Tarts? And what are UPFs?
Dr. K: The reality is that much of our processed food is full of macronutrients, but severely lacking in micronutrients. Ultra-processed foods (UPFs), such as Pop Tarts, have trivial amounts of vitamins and minerals even though they are loaded with carbs and the like. So, you might ask, what is the answer to better mental health? Actually, it is rather simple. Eat real foods. But I should note that not all processed foods are bad. In fact, previous to World War II, most people’s diets were limited by the season and location. But once foods started to be canned and frozen on a large scale, people all over the country could get healthy options, such as frozen peas, anytime they wanted. But the key here is that they remained real food, not the UPFs that followed in mass quantity.
Dr. S:So, there has been a lot of press lately about the Mediterranean diet being a great way to eat healthy. If we eat a Mediterranean type of whole foods diet, will we all have really good brain health? And by the way, can we afford to eat that way?
Dr. K: The Mediterranean diet is definitely a good start, but research has shown us that there are two major reasons this might not be enough for some people. One, there is a good degree of individual difference when it comes to how people metabolize food, and the specific nutrient needs they have. Thus, while eating healthy is important, certain individuals need additional micronutrient options, such as supplements, to help maximize brain health. In addition, due to a variety of factors, the soil most plants are grown in today in North America is less nutrient dense than it was decades ago. Thus, the depleted soil produces plants with a reduced concentration of minerals and vitamins — the carrots you eat are not the same, nutritionally, as those your grandmother ate. For these reasons, a broad-spectrum micronutrient supplement may be important for some people. As for affordability, research shows that you can save money eating a whole foods type of diet. This will surprise some people, but we explain how and why in our book.
Dr. S:So, it sounds like you are saying there is a place for supplements, even for some people who are eating a healthy, diverse diet?
Dr. K: Yes, the research indicates this is the case. But here is what might surprise many people, and this is why we set out to write this book. It is not just for physical reasons, but rather intellectual, psychological, and emotional ones. Research has consistently shown that a broad-spectrum micronutrient can benefit kids and adults in areas such as attention, mood, and cognitive functioning. In fact, one of the most consistent findings is that micronutrients improve emotional regulation.
Dr. S:Speaking as a parent of many kids, I can’t think of anything more important in our house than our kids regulating their emotions better. Okay, final question: Let’s say I am an adult who is reasonably healthy with no known medical conditions. Beyond everything else you just said, is there any other reason I should pay close attention to my nutrition?
Dr. K: As someone in her 70s, I have to comment on how nutrition relates to the risk for dementia. Studies have clearly demonstrated that nutrition is a key factor related to brain health across the lifespan, and that those who eat highly processed diets have increased cerebral atrophy (brain shrinkage) as they get older.
In the end, it is clear that nutrition is the foundation of not just our physical health, but our mental health, too. Our hope is that this book will be a catalyst for the general public and mental health clinicians to take this more seriously.
Readers can find out more information about the book and Dr. Kaplan at her website: BonnieJKaplan.com.