Healthy nutrition for brain disorders and mental complaints: 2 diets that work

Source: Jeleefstijlalsmedicijn

In recent decades, the number of people suffering from brain disorders such as depression and anxiety disorders and neurological conditions such as Alzheimer’s, ADHD, autism, and Parkinson’s has increased significantly. In this article, I show that genetic causes, better diagnosis, and changes in society cannot explain this increase in brain disorders. Where does the increase come from?

Research conducted in the last ten years shows that changes in our dietary pattern can partly explain the increase. We eat and drink much more industrially produced food (think of soft drinks, chips, cookies, and seed oils) and simultaneously consume more carbohydrates (from pasta, bread, rice, candy, cookies, and soft drinks).

In this article, I describe how that dietary pattern affects the functioning of our brain, resulting in mental disorders. I conclude the article with the question: ‘What can you do about this?’ To that end, I discuss four diets: our ‘normal’ Western diet and three alternatives — vegan, Mediterranean, and ketogenic — with their effect on the brain. Two of these diets turn out to be healthy nutrition for brain disorders, two others are not.

For writing this article, I used the book Brain Energy by Chris Palmer, assistant professor at the medical faculty of Harvard.

This article offers nutritional advice to support mental well-being. However, it is not a substitute for professional medical advice or medical treatment. Always consult your doctor for personal health matters.

Definition

Mental disorders as a result of metabolic disorders in the brain are abnormalities in the way the brain processes energy, produces and breaks down neurotransmitters, and performs other biochemical activities. These abnormalities can lead to the symptoms we associate with mental disorders.

1. The growth in brain disorders, mental complaints, and the ineffectiveness of treatments

In psychology, the ‘bio-psycho-social’ model is common for explaining brain disorders and mental complaints. However, that model cannot explain the rapid growth in the number of people suffering from these conditions. Moreover, the model falls short in finding the causes of disorders, which explains why so few patients with mental complaints recover from them.

1.1. The growth in brain disorders and mental complaints

In recent decades, there has been enormous growth in various brain disorders in the Netherlands. One in four adults is now affected. This is what research (Trimbos, 2022) shows:

• Nearly half (48 percent) of adults in the Netherlands have ever had one or more brain disorders and mental complaints. Anxiety disorders occur most frequently, namely in 15 percent of adults, followed by depressive disorder (9 percent).
• The number of people with mental complaints is rising rapidly. In 2008, 17 percent of adult Dutch people had a mental condition. Just over ten years later, in 2020, that had increased to 26 percent.

1.2. What causes mental complaints?

The most used model to understand mental disorders is the ‘bio-psycho-social model’. The model was introduced by George Engel in the 1970s. It states that three factors play a role in the development of the disorders:

• Biological: physical aspects such as genetics and neurotransmitter imbalance.
• Psychological: this concerns emotions, thoughts, and behavior.
• Social: this is about relationships, culture, and environmental factors.

Engel’s model was revolutionary because it deviated from the then prevailing medical approach that focused mainly on purely biological causes of diseases.

1.3. What can explain the rapid increase?

The bio-psycho-social model falls short as an explanation for the growth in mental complaints:

• Biological factors. It is unlikely that genetic factors can explain the rapid growth in mental disorders. First, because genetic causes play little or no role in many mental disorders (Unesh, 2014). Additionally, because our genes change only slowly.
• Social and psychological factors. It may be that our society places higher demands on people than a few decades ago. That could lead to more stress and thus an increase in anxiety disorders and depression. But neurological abnormalities such as schizophrenia, bipolarity, and autism are also growing rapidly. Social and psychological factors cannot explain the growth in such neurological disorders.

1.4. The ineffectiveness of current treatments

What makes the rapid growth in brain disorders and mental complaints worse is that current treatment methods are not very effective. The usual way to address brain disorders is with medication (to address the biological causes) and through psychotherapy (to counteract the psychosocial causes).

What is known about the effectiveness of these treatments?

• Alzheimer’s and Parkinson’s. For neurological abnormalities such as Alzheimer’s and Parkinson’s, there are currently no cures. Current treatments focus mainly on controlling or reducing symptoms.
• Autism, bipolar disorder, and schizophrenia. The success rates of treatments are low. Research shows that antipsychotics have a good effect in only 23 percent of patients with schizophrenia (Leucht, 2017).
• Depression. Research shows that 50 percent of patients experience a good effect from medication (McCormack, 2018). However, 90 percent of patients with depression retain symptoms permanently, even with treatment.

This ineffectiveness of treatments leads to frustration in patients. They experience no lasting relief from their condition.

If we know that conventional treatments for mental disorders and mental illnesses do not work well, are there other causes that we can address?

2. A common cause of brain disorders?

We know from research that every form of brain disorder or mental complaint increases the chance of having another condition two to thirty times. This points to a possible common underlying cause.

2.1. Various brain disorders occur together

Research shows that 45 percent of all patients with a form of brain disorder or mental complaint are also diagnosed with another form of mental disorder (Kessler, 2005). A large Danish study showed that every mental disorder is related to every other mental condition. Having one disorder increases the chance of another condition by a factor of two to thirty (Plana-Ripoll, 2019).

Some examples:

• Patients with depression have twice the chance of developing Alzheimer’s (Ownby, 2006).
• Almost all patients with bipolar disorder have depressive complaints (Himelhoch, 2012).
• Patients with an anxiety disorder have eight to thirteen times greater chance of schizophrenia (Plana-Ripoll, 2019).
• Patients with schizophrenia have twenty times greater chance of developing Alzheimer’s (Stroup, 2020).
• Patients with epilepsy have three to six times greater chance of developing anxiety disorders (Kanner, 2011).

2.2. Brain disorders that often occur together may have a common cause

When scientists see that two conditions often occur together, they suspect a common cause. Think of a runny nose and a sore throat: these are not separate conditions, but are both symptoms of a cold. With the common cause being the cold virus.

If you know the cause of a condition, you are better able to find effective treatments. This also applies to brain disorders. What could their common cause be?

Metabolic conditions: obesity, type 2 diabetes, and cardiovascular disease

Our metabolism consists of processes that convert nutrients such as carbohydrates, fats, and proteins into energy and building blocks that our body needs. A metabolic disorder is a condition where normal metabolism is disrupted. This can lead to, for example, type 2 diabetes, cardiovascular disease, and obesity, which often occur in combination:
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• Obesity, excessive fat accumulation in the body, increases the risk of cardiovascular disease, type 2 diabetes, and even certain forms of cancer.\
• Type 2 diabetes is characterized by reduced sensitivity to the hormone insulin (‘insulin resistance’), which leads to elevated blood sugar levels. This can lead to complications such as kidney failure, nerve damage, and heart problems.\
• Cardiovascular diseases, including heart attacks and strokes, are often caused by atherosclerosis, where blood vessels narrow due to plaque buildup. These conditions can be worsened by high blood pressure and diabetes.
  
  These conditions are related to our lifestyle. For example, the Interheart study from 2004 shows that 90 percent of heart failure in men and 94 percent in women are caused by lifestyle factors such as smoking, overweight, alcohol consumption, and not exercising regularly (Yusuf, 2004).

3. Mental disorders as a metabolic disorder of the brain

Brain disorders are not only related to each other but also to metabolic health. This points to a possible common cause. An important indication is that in people with neurological abnormalities and mental complaints, disturbances in the energy balance of the brain are often observed.

3.1. Brain disorders often occur together with metabolic ill health

Research shows that patients with a diagnosed mental disorder are three times more likely to have obesity and die seven to ten years earlier. What do they die from? Often these are metabolic diseases such as type 2 diabetes, heart conditions, and strokes.

The connection between brain disorders and metabolic conditions can go both ways. From mental disorders to metabolic conditions:

• Patients with depressive complaints have sixty percent more chance of diabetes (Mezuk, 2008).
• Patients with schizophrenia have three times greater chance of diabetes (Rajkumar, 2017).
• Children with autism have forty percent more chance of obesity (Mische Lawson, 2016).
• Patients with schizophrenia have 53 percent greater chance of cardiovascular disease (Fan, 2013).
• Patients with depression have five times more often heart failure and strokes (Astrom, 1993).
• Patients with schizophrenia have 62 percent chance of obesity later in their life (Strassnig, 2017).
• Patients with a mental disorder have three times more often obesity (Afzal, 2021).

From metabolic conditions to brain disorders and mental complaints:

• People with obesity have sixty to seventy percent more chance of epilepsy (Gao, 2008).
• Weight gain around puberty gives four times higher chance of depression as a young adult (Perry, 2021).
• Patients with diabetes have two to three times greater risk of depression (Semenkovich, 2015).
• People with obesity have fifty percent more chance of bipolar disorder (Palmer, page 66).
• Diabetes patients have fifty percent greater chance of developing epilepsy (Baviera, 2017).
• People with obesity have twice the chance of multiple sclerosis (Alfredsson, 2019).

This connection may point to a possible common cause. How does metabolism affect brain function?

3.2. Many brain disorders are linked to disturbances of metabolism in the brain

Research shows that many mental disorders are linked to disruption of metabolism in the brain. Think of depression, anxiety disorders, autism, ADHD, PTSD, schizophrenia, bipolarity, addictions, Alzheimer’s, Parkinson’s, and epilepsy.

Examples of research showing these relationships:

• Depression. Researchers collected 46 studies on blood values and depression. They concluded that metabolic changes in the blood were associated with depression (Pu, 2020). Other researchers saw worsened metabolism during depressive episodes of patients. The worsened metabolism recovered after six months of treatment with antidepressants (Tayeb, 2023). Yet other research shows that addressing insulin resistance in the treatment of depression leads to faster recovery and prevention of relapse (Watson, 2018).
• Bipolarity. There is much evidence for an association between metabolic abnormalities and bipolar disorder. Researchers see that patients during manic periods have increased energy production in the brain and during depressive periods have an energy deficit (Morris, 2017).
• Alzheimer’s. Researchers call Alzheimer’s ‘type 3 diabetes’. Studies show that Alzheimer’s is a form of diabetes that specifically affects the brain and has molecular and biochemical features that overlap with type 1 and 2 diabetes (De la Monte, 2008).

How can disturbances in the brain’s energy balance cause mental disorders? What is known about this?

The energy balance of our brain

Our brain is only 2 percent of our body weight but uses as much as 20 percent of our energy. A disturbance in metabolism disrupts the energy balance and leads to dysfunction of mitochondria (the ‘energy factories’ of our cells).

Our brain contains an enormous number of neurons: about one hundred billion, more than ten times as many as there are people on earth. Each of these neurons uses energy. Neurons get this energy in the form of the molecule ATP (adenosine triphosphate). Each neuron uses per second 4.7 billion ATP molecules. The molecules are produced in the mitochondria. Cells in our body contain three to four hundred mitochondria, but brain cells can contain thousands of mitochondria.

How do the mitochondria in the brain get energy? The brain can use two sources: glucose and ketones.
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• Glucose is a type of sugar that circulates in the bloodstream and is used by almost all cells in the body as an energy source. Glucose is transported via the blood to the brain and let through the blood-brain barrier.\
• Ketones are energy molecules produced by the liver from body fat. This happens when only a limited amount of glucose is available from food. The ketones are transported via the blood to the brain.

3.3. Insulin resistance affects energy availability in the brain

Insulin resistance (reduced sensitivity to the hormone insulin) is a symptom of metabolic ill health. As a result of this resistance, cells have difficulty absorbing glucose from the blood as energy. This problem exists not only in the body but also in the brain.

Our brain is highly dependent on energy availability for its functioning. Both acute and chronic problems with energy availability affect brain function:

• Acute energy deficit. An example of this is hypoglycemia or ‘low blood sugar’. This occurs when people who are used to eating lots of carbohydrates don’t eat for a while. In mild cases, it leads to fatigue and difficulty concentrating. More serious cases result in headaches, depressive feelings, or even hallucinations.
• Chronic energy deficit. An example is type 2 diabetes. In type 2 diabetes, cells have difficulty converting glucose (sugar) into energy due to insulin resistance. This first leads to mild symptoms such as fatigue and difficulty concentrating. More serious cases lead to problems with the eyes, nerves, brain, or even heart attacks and strokes.

It is striking that these acute and chronic symptoms first occur in the brain, before the rest of the body is affected.

To conclude this section, a brief summary:

Can people who are insulin resistant switch to ketones as an alternative energy source for their brain? Unfortunately, this is not easy. People with insulin resistance often eat a diet rich in carbohydrates (bread, pasta, rice, cookies, candy, and sugary drinks). Such a diet increases the risk of insulin resistance. At the same time, such a diet leads to excess glucose in the blood. And if there is a lot of glucose in the blood, the body will not produce ketones. Thus their brain is cut off from this alternative energy source.

• We know that mental disorders often occur together with metabolic ill health.
• We see this reflected in mental disorders where metabolism in the brain is disrupted.
• Brains are very sensitive to getting enough energy.
• The brain can use both glucose and ketones as an energy source.
• However, insulin resistance limits the supply of needed energy from glucose.
• Eating carbohydrate-rich food prevents the production of ketones.
• Insufficient energy from glucose and ketones leads to energy deficits in the brain.

The good news is that if we want to combat mental disorders, in addition to medication and psychotherapy, we have an extra tool in hand: healthy nutrition for brain disorders.

Reversing insulin resistance and type 2 diabetes with lifestyle

In this article, we discuss the crucial role of nutrition in managing and possibly even reversing insulin resistance, prediabetes, and type 2 diabetes (T2D). Type 2 diabetes is a chronic condition that affects millions of people worldwide.

4. Healthy nutrition for brain disorders. Four possible diets

In this chapter, we discuss four diets and their effect on our brain:

• Standard Western diet
• Vegan diet
• Mediterranean diet
• Ketogenic diet.

We show that the standard Western diet is harmful, the vegan diet falls short, and that the Mediterranean diet and ketogenic diet are healthy nutrition for brain disorders.

4.1 The standard Western diet is harmful to the brain

The ‘normal’ diet in the Western world consists largely of ultra-processed food. More than seventy percent of all food products in Dutch supermarkets are ultra-processed. More than half (61 percent) of our energy intake consists of ultra-processed food (Vellinga, 2022).

Ultra-processed food is food and drink that is industrially produced. It contains ingredients that you probably don’t have in your kitchen. Examples of ultra-processed food are soft drinks, chips, cookies, seed oils, candy, ready-made meals, fast food, cold cuts, instant soups, sauces, mayonnaise, energy drinks, ice cream, cake, and pizza.

Also read Ultra-processed food: more than half of our diet and deadly

Ultra-processed food can lead to damage to our brain. A possible mechanism for this is that ultra-processed food contains many added sugars, which increases the risk of insulin resistance.

Some examples of research showing that ultra-processed food is associated with mental disorders:

• Depressive complaints. Multiple studies show that people who eat more ultra-processed food have a significantly increased risk of depressive complaints (Samuthpongtorn, 2023, Gomez-Donoso, 2020). One study showed that avoiding ultra-processed food in a short time (three weeks) leads to a substantial reduction in depressive complaints (Francis, 2019).
• Dementia. Research shows a strong connection between consumption of ultra-processed food and developing dementia. Every ten percent of ultra-processed food in our diet that we replace with lightly processed or unprocessed food leads to 19 percent lower risk of dementia (Huiping, 2022). Other research shows that people who consume the most ultra-processed food have 44 percent greater chance of dementia (Henney, 2023).

4.2. The vegan diet falls short for the brain

On a vegan diet, many people develop deficiencies in nutrients such as vitamin B12, iron, zinc, iodine, and omega 3 (Bakaloudi, 2021). These are nutrients that are only or mainly found in foods of animal origin. A deficiency of each of these five nutrients is associated with an increased risk of several mental disorders.

Nutrient deficiency

Risks of mental disorders

Vitamin B12

Behavioral change, psychosis, intellectual disabilities (Kennedy, 2016)

Iron

ADHD (Granero, 2021), anxiety disorders, depression, psychosis, sleep disorders (Lee, 2020)

Zinc

ADHD (Ghoreishy, 2021), depression, psychosis (Petrilli, 2017)

Iodine

Anxiety disorders (Turan, 2020)

Omega 3 (DHA and EPA)

ADHD, autism, mood disorders, schizophrenia, dementia (Lange, 2020)

4.3. The Mediterranean diet: effect on depression and Parkinson’s

The Mediterranean diet (mainly fruit, vegetables, olive oil, whole grain, beans, nuts and seeds, meat and fish) appears to reduce symptoms of depression and Parkinson’s.

• Depression. Research shows that people who strictly adhere to the Mediterranean diet have 30 percent less chance of depression (Psaltopoulou, 2013). This idea was tested by other researchers by putting patients with depression on a Mediterranean diet. They were compared to a group of patients who ate candy, refined grains, fried food, fast food, and processed meat and drank sugary drinks. After twelve weeks, 32 percent of the patients on the Mediterranean diet were symptom-free, compared to 8 percent of patients in the control group (Jacka, 2017).
• Parkinson’s. There is much evidence showing that following the Mediterranean diet delays the onset of Parkinson’s and slows clinical progression (Bianchi, 2022).

4.4. The ketogenic diet for epilepsy, Alzheimer’s, MS, and other neurological conditions

The ketogenic diet was developed in 1921 by physician Russell Wilder for the treatment of epilepsy in children. The diet includes products such as meat, fish, eggs, nuts and seeds, full-fat dairy products, and olive oil. It is low in carbohydrates and high in fat and intended to bring the body into a state of ketosis. Then the body uses ketones instead of glucose as the primary energy source. By significantly limiting carbohydrate intake (to less than 20 or 50 grams per day) and eating more fats, blood sugar levels drop and the number of ketones in the body increases.

Some examples of the effect of the ketogenic diet on mental disorders:

Epilepsy

Research shows that children on the ketogenic diet have three to six times greater chance of preventing epileptic seizures (Martin-McGill, 2020).

Alzheimer’s

Research shows that memory, executive functions (for example planning and concentration), and language function improve when patients drink a ketone drink daily (Fortier, 2020). The effect the researchers find is moderate to large, which is exceptional for this disease. In other research where Alzheimer’s patients were put on a ketogenic diet, patients improved their daily functioning and quality of life, two factors of great importance for people with Alzheimer’s (Philips, 2021).

Autism

Changes in nutrition can help the brain work better and lower insulin, which may be good for people with autism. Ketones from nutrition can be a good alternative energy source for the brain (Manco, 2021).

Bipolarity

Research in a group of therapy-resistant bipolar patients with a ketogenic diet led to significant and substantial improvements in symptoms of depression and psychosis (Danan, 2022).

MS

Research shows that a ketogenic diet has positive effects in people with multiple sclerosis. Study participants reported a decrease of nearly fifty percent in fatigue and depression. Participants also showed significant improvements in their functional capacities such as walking and using their hands (Brenton, 2022).

There are two variants of the ketogenic diet:

• The ‘normal’ ketogenic diet, with approximately 60-75 percent of calorie intake from fat. This diet is usually aimed at weight loss, improved metabolic health, and energy improvement.
• A therapeutic ketogenic diet. This diet gets 70-80 percent of calories from fat, achieving a higher concentration of ketones (0.5-5.0 mmol/l). This diet is often used as an intervention for specific health problems such as epilepsy, neurological conditions, and type 2 diabetes.

5. And now? What can you do with nutrition?

What you do with the above knowledge depends on how you are doing physically and mentally. If you are metabolically or mentally unhealthy, you have a stronger reason to make changes in what you eat. This motivation is important because changing your diet is not easy.

It goes beyond the scope of this article to elaborate on how you make changes in your diet, but here are briefly three ideas about what you could change.

• If you are healthy (mentally and physically), it is still worth reducing your intake of ultra-processed food. After all, over time, more damage will occur at the expense of your health.
• If you notice beginning metabolic ill health such as increasing weight, more fat around the abdominal area, fatigue, and hunger a few hours after eating, this may indicate the beginning of insulin resistance. The Mediterranean diet can then help. Avoid drinks with (fake) sugars and limit yourself to water, tea, and coffee.
• If you suffer from a brain disorder or have mental complaints, the ketogenic diet has the most demonstrable effect. This means more meat, fish, eggs, olive oil, butter, and other fatty products and fewer carbohydrates in the form of potatoes, bread, pasta, rice, and legumes.

6. Conclusion: healthy nutrition for brain disorders

The number of people suffering from mental disorders is growing rapidly and current treatments offer only limited relief. This is because we overlook an important cause of these brain disorders: our Western dietary pattern.

Through our eating pattern with a large share of ultra-processed food, we are becoming increasingly metabolically unhealthy, with obesity, type 2 diabetes, and cardiovascular disease as a result. These consequences affect not only our physical health but also damage our mental health, resulting in mental disorders. After all, the brain is part of the body.

The good news is that we can address mental disorders with more than just medication and psychotherapy. We can also adjust our dietary pattern. With diets such as the Mediterranean diet and the ketogenic diet, we can address the causes of mental disorders and reduce symptoms. Moreover, these diets ensure better metabolic health and thus a smaller chance of cardiovascular disease, type 2 diabetes, and obesity.

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Veelgestelde vragen

What is the connection between nutrition and depression?

Research shows that certain dietary patterns can reduce depressive symptoms. People who eat a lot of ultra-processed food have an increased risk of depression, while people who follow a Mediterranean diet have 30% less risk. In a clinical study, 32% of patients on a Mediterranean diet were symptom-free after 12 weeks, compared to only 8% in the control group.

How can a ketogenic diet improve mental health?

A ketogenic diet causes the body to use ketones as the primary energy source instead of glucose. This has positive effects on various mental conditions: it reduces epileptic seizures by 3-6 times, improves memory functions in Alzheimer's patients, and leads to substantial improvements in therapy-resistant bipolar patients. MS patients also report a nearly 50% reduction in fatigue and depression.

What are the benefits of a Mediterranean diet for the brain?

The Mediterranean diet (rich in fruit, vegetables, olive oil, whole grains, beans, nuts, seeds, meat, and fish) reduces symptoms of depression and Parkinson's. It delays the onset of Parkinson's and reduces clinical progression. For depression, people who strictly adhere to this diet have 30% less chance of developing this condition.

How does ultra-processed food harm our brains?

Ultra-processed food (such as soft drinks, chips, cookies, seed oils, fast food) contains many added sugars that increase the risk of insulin resistance and diabetes, which is harmful to the brain. Studies show that people who eat more ultra-processed food have an increased risk of depressive symptoms and dementia. Every 10% of ultra-processed food replaced by less processed food leads to 19% lower risk of dementia.

Which diet helps with anxiety disorders?

Metabolic disorders in the brain contribute to various mental conditions, including anxiety disorders. Both the Mediterranean and ketogenic diet can help because they reduce insulin resistance and improve the brain's energy balance. It is also known that nutritional deficiencies such as iodine deficiency increase the risk of anxiety disorders.

Does nutrition help against Alzheimer's and Parkinson's?

Yes, nutrition plays an important role in these conditions. Researchers even call Alzheimer's 'type 3 diabetes' due to the overlap with metabolic disturbances. In Alzheimer's patients, memory, executive functions, and language improve when they consume ketones. The Mediterranean diet delays the onset of Parkinson's and reduces clinical progression. Conversely, people who consume a lot of ultra-processed food have a 44% higher risk of dementia.

How does insulin resistance affect the brain?

Insulin resistance makes it difficult for brain cells to absorb glucose from the blood, leading to energy deficit in the brain. This energy deficit first causes mild symptoms such as fatigue and concentration problems, but can eventually lead to serious mental disorders. People with a carbohydrate-rich diet also have less access to ketones as an alternative energy source, which exacerbates the problem.

Which dietary pattern helps best against mental disorders?

Both the Mediterranean and ketogenic diet have positive effects on mental disorders. For people with existing mental conditions, the ketogenic diet has the most demonstrable effect. The Mediterranean diet is suitable for people with beginning metabolic ill health. For everyone, reducing ultra-processed food and limiting sugary drinks is important.