Can Nutrition Treat Mental Disorders?

What you eat has a profound impact not only on your metabolic health but on your mental health.

Updated 09/28/2023

(Note: This is a transcript of a video involving Dr. Bret Scher, MD FACC, and Dr. Chris Palmer, MD, psychiatrist at Harvard Medical School and McLean Hospital.)

Dr. Scher

In today’s discussion, we’re going to cover how what you eat can make a substantial impact not just on your metabolic health, but also your mental health. I’m going to describe the dietary changes that experts agree apply to everyone and that are sure to improve your health. Then, we’ll go further, focusing specifically on therapeutic nutritional ketosis. After reading this article, you should better understand how therapeutic nutritional ketosis can improve psychiatric symptoms or symptoms of mental illness and why you may want to consider discussing it with your healthcare provider.

But first, please remember that our content is for informational purposes only. We’re not providing individual or group medical or health care advice or establishing a provider-patient relationship. Many of the interventions we discuss can have dramatic or potentially dangerous effects if done without proper supervision. Consult your healthcare provider before changing your lifestyle or medications. 

In our previous articles, we described the correlation between insulin resistance, metabolic dysfunction, and mental illness. We also explained how you can know if you have insulin resistance. Now, we’re going to go into more detail about how what you eat can directly impact your metabolic health and your mental health. 

Let’s start with the easy part and the dietary advice that applies to pretty much everyone: get off the Standard American Diet (also called the standard western diet or the standard industrialized diet) that combines high-carb, high-fat, high-calorie, highly processed foods. Instead, focus on whole, natural food sources, and avoid almost anything that’s refined, processed, or composed of added calories with little nutritional value.

The added calories and the low nutritional value of ultra processed foods are a recipe for insulin resistance, metabolic dysfunction, and a roller coaster of rising and falling glucose and rising insulin levels. 

Now, before you get upset with me, let me clarify what I mean when I say this was the “easy” advice. What I mean is that this advice is easy to give. It’s a rare idea that almost all nutrition experts agree on, but I know it’s not always easy to implement. We live in a world that’s full of tempting foods, which are exactly the ones that we should avoid. If it was easy for everyone to follow this advice, we wouldn’t have the obesity, diabetes, and metabolic health crisis that we currently have, and we probably also wouldn’t have as bad of a mental health crisis. 

We have to be honest that the food environment we live in is working against us. The advice to eat all things in moderation and simply reduce your calories is often destined to fail, thanks to the ubiquitously easy availability of cheap, tasty, potentially addictive refined and processed products. It’s no secret that almost any diet that focuses on whole food sources is going to be better for metabolic and mental health than the standard industrialized diet.

Many people can see benefits from a whole-food vegan, vegetarian, Mediterranean, or other diets as long as it fits with their overall health and likes so that they can maintain it long-term in a healthy way. 

But the question we have to ask is: is it enough to simply reduce refined and processed foods? Or is there something potentially even more effective for metabolic and mental health?

At Metabolic Mind, we want to explore the concept that simply eating better, although healthful, may not be the most impactful approach. Instead, we hypothesize that therapeutic nutritional ketosis may be the most effective nutritional approach for mental health and treating symptoms of mental illness. 

But before we go any further, let’s make sure we’re on the same page on what we mean by therapeutic nutritional ketosis.This refers to any nutritional approach that reduces carbohydrate intake low enough so your body changes from using glucose for fuel to using fat for fuel. That can be the fat you store in your body or the fat you eat. As a result, your body produces ketones, which the brain can specifically use for energy production. 

This is more than just a diet. It’s a powerful intervention that radically changes your body’s metabolism and how it produces energy. That’s why simply calling it a ketogenic diet doesn’t do it justice. It’s not what is sometimes promoted as the fad weight loss diet, but rather, it’s a therapeutic medical intervention that’s been around for over a century. 

So how can therapeutic nutritional ketosis benefit mental illness? We’ll get into that, but first, please remember that therapeutic nutritional ketosis or simply starting a ketogenic diet is a powerful health and medical intervention that can change your body’s metabolism and dramatically alter brain function. medication levels, sleep patterns, energy levels, and other physiologic functions. If you have a psychiatric diagnosis, symptoms of one, or take psychiatric medications, you should not start a ketogenic diet alone. Instead, you should only consider starting a therapeutic ketogenic intervention with careful monitoring from your health care provider or an experienced clinician. We hope you’ll learn from our information and take the information to your health care provider to discuss whether therapeutic ketosis is an appropriate, safe, and potentially effective intervention for you. 

Now back to the question: how can therapeutic nutritional ketosis benefit mental illness? There are at least two main ways, probably more, but two main ways. The first is a direct effect from ketones. Scientific studies have shown that, with a diagnosis of serious mental illness, seizures, or even dementia, brain cells have trouble efficiently using glucose for fuel. Essentially, there’s a disruption to the brain’s energy production. Ketones supply a completely different fuel that doesn’t depend on insulin or the cell’s ability to metabolize glucose. This can result in more efficient energy production for the brain.

Now, you might have heard that the brain can’t run 100% on ketones, and that’s true. Your brain will always require some glucose, which your body can produce by itself, even when you’re not eating carbohydrates. The best scientific evidence suggests that ketones can supply up to 70% of total brain energy. That’s a potentially huge benefit compared to the brain running 100% on glucose, which is what frequently happens in the setting of insulin resistance and metabolic dysfunction, especially on the standard industrialized diet. 

But more efficient energy production isn’t the only benefit making ketones offers. When the brain switches from glucose to ketones for the majority of its energy, there’s evidence of decreased neuroinflammation, something else that’s been implicated in the cause of mental illness.

There’s also a change in neurotransmitters with an increase in GABA and a decrease in glutamate. That combination can reduce the hyper-excitability of sick or diseased nerve cells. Furthermore, using ketones for fuel can improve the function of mitochondria, the energy producing part of the cell. 

Here’s Dr. Chris Palmer, who postulates that the mitochondria serve as a unifying root cause of energy dysfunction in mental illness.

Dr. Palmer

When you look at the neuroscience linking metabolic disorders or metabolic problems and mental disorders, especially serious ones like bipolar disorder, schizophrenia, and chronic depression, that research actually goes back a couple of centuries. We have known since the 1800s that diabetes and serious mental disorders are strongly connected and that families who have high rates of diabetes are more likely to have serious mental disorders and vice versa: in families with serious mental disorders, people are more likely to develop diabetes. 

Beginning in the 1940s, researchers began to identify all sorts of metabolic abnormalities in the bodies of people with mental illness. They took samples of blood from their veins and noticed increased levels of lactate, which is a biomarker of metabolic stress. Usually, we have increased lactate when we exercise, but they were noticing these increased levels of lactate in people with schizophrenia and bipolar disorder, even when they were relaxing. 

That research continued to escalate, and then, in the 1990s, we had neuroimaging studies and all sorts of lines of evidence that all converged on metabolism. Metabolism is extraordinarily complicated, though, and so is the brain. Researchers have been puzzled and overwhelmed by this complexity. Only over the last 20 years have we begun to see an entirely new body of research that helps us understand this complexity, and that body of research is focused on mitochondria. Most people know mitochondria as the powerhouse of the cell, but actually they do so much more than that. When you do a deep dive of the science of mitochondria and all of the different roles they play in cells and the human body, you can actually connect the dots of all of the factors that we know play a role in mental illness.

Mitochondria are involved not only in metabolic disorders like obesity, diabetes, and cardiovascular disease, but mitochondria are also directly involved in the production and regulation of neurotransmitters like serotonin and dopamine as well as some important hormones like cortisol, estrogen, and testosterone. They play a role in gene expression and inflammation as well.

When we look at that, when we look at this big picture of metabolism in mitochondria, we can actually begin to understand how symptoms of mental illness emerge; and, more importantly, how the causes lead to those symptoms; and, much more importantly, ways that we can intervene to stop the symptoms, put these disorders into remission, and restore people’s health and lives.

Dr. Scher

But remember, I said therapeutic nutritional ketosis has two potential effects. The benefits we’ve listed so far are the direct ketone effects. The other potential benefits come from improving insulin resistance and metabolic dysfunction.

Any diet that helps you reduce excess body fat, especially visceral fat, which is the fat around your belly and your inner organs, can likely improve insulin resistance, but a ketogenic diet is probably the most effective nutritional intervention given the combination of reduced body fat, decreased carbohydrates, and decreased insulin levels. This is very important to remember. As we’ve already mentioned, there is a tight association between insulin resistance, metabolic dysfunction, and mental illness and we know that psychiatric medications can induce insulin resistance. They can be very effective for treating acute psychiatric symptoms, but over the long run, they can induce insulin resistance. Therapeutic nutritional ketosis could help future health risks from the medications by reducing the risk of insulin resistance.

But remember: nutritional ketosis is a medical intervention that changes your metabolism. In reality, therapeutic ketosis should be prescribed just like a medication and should include a discussion of the risks and benefits as well as clear instructions on how to do it, and it should be used in conjunction with other psychiatric medications. In fact, nutritional interventions like ketogenic diets are typically initiated while keeping medication regimens the same, at least for some time, and in some cases as needed. Medications for sleep may be required during the initial transition into ketosis, which can occasionally cause insomnia.

So at this point, we’ve talked about the potential benefits and the potential precautions. You’re probably wondering why we’re so cautious about recommending starting a keto diet and only doing it under the guidance of your health care provider. Well, it turns out there are some potentially significant side effects and precautions. We’re going to cover those in much more detail in another article.

In the meantime, thanks for reading. Please take care of yourself, take care of others, and we’ll talk with you here next time here at Metabolic Mind.