Is There A Connection Between Gluten And Depression

Depression is more than simply feeling unhappy and it has several causes such as stressful events, loneliness or specific illnesses.¹ Could gluten be affecting your mental health and be one of the causes of depression?

The relationship between depression and gluten seems to be complex and many factors play a role in it. Various studies and theories exist explaining the reason of mood disorders in people with gluten-related disorders and evidence supporting an association between mood disorders and gluten-related disorders is increasing.

Overview

Depression is one of the most common mental disorders.

Data from WHO shows that in 2019, 280 million people were living with depression.² In 2020, the number of people living with anxiety and depression increased remarkably due to the COVID-19 pandemic, 26% for anxiety and 28% for major depressive disorders in just one year.

Celiac Disease

Recently, gastrointestinal and extra-intestinal complaints due to gluten-containing foods have been on the rise. Celiac disease is an autoimmune disease which is characterized by intestinal mucosal damage due to an immune response to gluten and improvement following a gluten free diet.³ A gluten free diet involveseliminating gluten products from the diet, such as wheat, rye and barley products. Although prevalence of celiac disease worldwide has been increasing and it affects every 1 in 100 people in the UK, celiac disease is sometimes not properly diagnosed. That is because celiac patients might present with many different kinds of symptoms or can sometimes be without any symptoms. 

Celiac disease patients can also present with mood symptoms. In fact, about 10% of celiac disease patients are found to have psychiatric disorders. Moreover, the percentage of celiac disease patients  affected by depression is higher than general population proportionally.⁴ An increased risk of depression in celiac disease patients with type 1 diabetes and autoimmune thyroiditis has also been observed.⁵

Other gluten-related disorders

Mood symptoms are also associated with other gluten related disorders such as non-celiac gluten sensitivity (NCGS)l.⁶ NCGS is a syndrome characterized by intestinal and extraintestinal symptoms due to ingestion of gluten-containing food in the absence of celiac disease or wheat allergy. Although the prevalence of non-celiac gluten sensitivity is not exactly known yet, it is suggested that it is more common than celiac disease. Non-celiac gluten sensitivity patients usually have similar symptoms to irritable bowel syndrome such as bloating, tummy pain and irregular bowel movements. However, non-celiac gluten sensitivity patients often have complaints outside of the intestines.⁵

Significant improvements in mood disorders including depression and psychosocial well-being have been observed in patients with gluten-related disorders such as celiac disease, irritable bowel syndrome and non-celiac gluten sensitivity after implementing a gluten-free diet.² The degree of improvement, however, is found to be related to good dietary adherence.

What is the connection between gluten and depression

Despite not having an exact explanation for the connection between gluten and mental state, there are some possible explanations suggested in the literature:

• Immune Response - Immune response to gluten might lead to depressive symptoms.⁴ Recent studies indicate increased gluten-related antibodies in people with major depressive disorder
• Nutritional deficiences - Nutritional deficiencies might be related to impaired mood and vitamin B intake was found to improve depression in adults with chronic celiac disease on a gluten-free diet⁴
• Cortisol Levels - Gluten could to alteration of cortisol levels which are found to be higher in people with a poor mental state. However, a study found no change in salivary cortisol secretion, making this explanation unlikely
• Serotonin Levels - Gluten can affect the amount of serotonin by limiting the amount of available tryptophan, which is a precursor amino acid for serotonin.⁶ Serotonin is a neurotransmitter, which is found in the brain and responsible for feelings of happiness. A study on rats showed that brain serotonin levels decreased after the rats were fed wheat. However, whether this is applicable for humans, or if this effect still occurs when rats are only fed gluten itself instead of wheat has not been clearly examined yet
• Exorphins -  Endorphins are opioid peptides that act in a similar way to morphine and they are produced in the body.⁶ Exorphins, on the other hand, are also opioid peptides, but they come from outside the body. That means, gluten exorphins are products of gluten digestion. These gluten exorphins have an effect on intestinal function as well as various mental processes if they reach the brain
• Gut bacteria - According to a study, celiac disease patients have intestinal dysbiosis, a condition where the gut bacteria are out of balance, and this condition can be resolved following a gluten-free diet. This suggests, instead of celiac disease, it is gluten itself which might be causing the bacterial imbalance. There is already a lot of research in rats that shows the effects of gut bacteria on various mental processes but there is also some studies demonstrating this to humans as well⁶

Can I improve my mood and mental health by going gluten free

A Gluten-free diet might be effective in improving mental health for those with gluten intolerance. Although the association between gluten and mood disorders in gluten-susceptible individuals are reported in the literature, effects of gluten exposure in terms of mental health in people without gluten-related disorders are not fully understood yet and require further research.⁴ Therefore, It might be a good idea to consult a healthcare professional to assess the benefits of a gluten-free diet in case of experiencing any mood changes or other symptoms after consuming gluten. Otherwise, any change of dietary intake of gluten without any symptoms may not be beneficial regarding your mood.

Summary

Depression and anxiety are the most common two mental conditions. Depression has been linked to many causes, and according to some studies, one of them could be gluten.

Celiac disease and non-celiac gluten sensitivity are conditions in which the body is affected due to consuming gluten. In those with gluten-related disorder, gluten might cause intestinal symptoms as well as symptoms outside of the digestive tract, including mood-related symptoms.

Despite the fact that the relation between gluten and mood disorders in people with gluten-related disorders has been shown in various studies, further research is needed to confirm this relation for people without any gluten-related symptoms or diseases.