Food as a Treatment for Mental Health2022-11-13

Let food be thy medicine and medicine be thy food.


There is emerging evidence that diet can affect mental health. A comprehensive way of looking at this may be useful. Which of the three main types of foods (carbohydrates, proteins, and fats) affect primarily which of the three main dimensions of mental health (anxiety, mood and cognition)? And what is the optimal timing, quantity, and fit to the patient?

Anxiety may be decreased primarily by carbohydrates, at least in the short-term. Hence the “self-medication” with carbohydrates seen in anxious individuals. Slow carbohydrates may be better in the long-term. Mood may be increased primarily by proteins. Hence the increased incidence of depression in low-protein/vegan diets. Cognition may be improved primarily by good fats, i.e. poly-unsaturated fatty acids. Hence the evidence for a diet high in fatty fish as benefit cognition and delating Alzheimer’s disease. A Mediterranean or MIND diet seems to provide the optimal balance of carbohydrates, protein and good fats, potentially leading to optimal balance of anxiety, mood and cognition.

So what is the role of a ketogenic diet, high in proteins and fats, with very few if any carbohydrates? There is emerging evidence it can have positive effects in psychiatric disorders. It has been known for decades that a ketogenic diet can help with seizure disorders. What is new is the interest in its effects on anxiety, mood, and cognition. Based on the above framework, it should have an anti-depressant and pro-cognitive effect, with some potential increase in anxiety due to lack of carbohydrates. Oftentimes, however, improving mood indirectly also decreases anxiety. In some ways a ketogenic diet may have similar effects to mood stabilizers such as lithium and valproate, working broadly to optimize brain function across diagnoses. Looking at blood biomarkers in individuals on a ketogenic diet may solidify the analogy. It remains to be seen how long individuals should be on a ketogenic diet, on how much proteins and fats and how little carbs, and for what diagnoses. For long- term maintenance and prevention, a less absolute version of it, with some carbohydrates from vegetables and fruits, may be optimal. So whether that is called a protein and fat rich Mediterranean diet, or a light ketogenic diet, becomes semantics.

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