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Due to the nature of my research and teaching, I have been asked one question more often than any other: what can I eat to make myself mentally healthy and become smarter? After spending more than forty years conducting research on the effects of food and drugs on the brain, my answer evolved into the following.
First, a few facts that everyone is already entirely aware. People generally have poor diets by almost any definition of the term. We eat too much fat, salt and sugar. We consume too much alcohol and nicotine and exercise too little. Most of America, regardless of age or socioeconomic status, is overweight or obese. Our bodies are storing too much fat; this fat produces a harmful environment of inflammation, oxidative stress and physiological imbalance that often leads to the metabolic syndrome. Simply stated, our lousy diet generates an environment in our body that ages us too quickly and impairs our thinking.
Thus, your question should actually be the following: what should I stop eating to avoid becoming unhealthy and stupid?
A diet rich in fresh fruits, vegetables and whole grains combined with reduced caloric intake, is ideal (and the one universally recommended) because it will compensate, and partially reverse, for the numerous negative effects of your current diet. Dieticians, physicians and all other health care providers beg their patients to change their diet; patients rarely do.
Some mental health disorders are caused by poor diets. The most common mental health disorder is depression. Obesity, and the presence of too much body fat, underlie our vulnerability to depression. People who lose body fat, via exercise or liposuction, experience improved mood and cognitive function. Thus, excessive body fat can make you both depressed and stupid and also makes it less likely that you will respond to anti-depressant therapy. Today, an overwhelming amount of scientific evidence obtained across a wide spectrum of medical disciplines strongly argues that obesity accelerates brain aging, impairs overall cognitive function and, ultimately, is responsible for the numerous processes that kill us.
Sugar is not harmful to your brain or body. From your brain’s perspective, dietary sugar is indispensable. Without a constant uninterrupted supply, you will quickly lose the ability to think then slip into a coma and die. You need sugar. However, diets high in sugar lead to metabolic diseases which have significant negative effects on cognition.
A small percentage of the general population are vulnerable to the lack of specific nutrients in their poor diet. This category of nutrients often includes vitamins and some minerals. Adding those nutrients back to their diet is often beneficial. However, numerous studies have now conclusively shown that for the overwhelming majority of us, supplements with vitamins and nutrients are a waste of money.
In contrast, a small percentage of the general population are vulnerable to the presence of specific nutrients in their poor diets. A good example of such a nutrient is gluten. If you are sensitive to gluten, do not eat it. If you are not gluten-sensitive then avoiding gluten is a bad idea according to the results of a study involving over 15,000 participants who were followed for thirty years. The American College of Cardiology now strongly recommends against the adoption of gluten-free diets for people without a medical necessity. Gluten-free diets, like so many other fad diets of the past and present, have been promoted by uninformed nutritional prophets using dietary scare tactics to scam a few dollars from a misinformed public.
We are often told that our diet affects our health and mood. That’s a true statement, but it does not quite represent the way that our body works: in reality, a healthier diet can only compensate for the consequences of your current lousy diet. Fruits and vegetables and whole grains cannot boost your mental health, they will not produce euphoria or reverse your depression; they can only help to undue the damage that your diet is already causing to your mental health.
No diet, no nutrient, no drug (do not believe the nonsense you have read about nootropics, a 21st century brain placebo) has ever been proven scientifically to enhance health or brain function. The advice you receive so often from your health care provider is designed to convince you to stop your poor diet in order to avoid becoming unhealthier and further cognitively impaired. Therefore, chose your diet wisely, your longevity and happiness depend upon it.
© Gary L. Wenk, Ph.D. Author of Your Brain on Food, 3rd Edition, 2019 (Oxford University Press)
