Major Depressive Disorder and Food Intolerances

There has been more and more research lately into a possible connection between the gut and major depression. This is a hopeful new line of research into the development and prevention of major depression.

What is Major Depressive Disorder?

Major depressive disorder is characterised by experiencing at least 5 of 8 pre-defined depressive symptoms for a minimum of 2 weeks, consecutively. At least one of which must be, either (1) depressed mood, most of the day or (2) loss of interest or pleasure. The length of symptoms is a key factor in distinguishing major depression from a usual low mood.

Inflammation and Major Depression

The suspected link between major depressive disorder and the gut stems from the association of inflammation and depression. It has been noted numerous times that anti-inflammatory interventions such as supplementing with omega 3’s and exercising have a substantial effect on mood in depressive patients with heightened inflammation.

“…a theme across research with cytokine antagonists, omega-3 fatty acids, celecoxib, and exercise is that anti-inflammatory interventions have a substantially greater impact on mood in individuals with heightened inflammation. Thus, when inflammation and depression co-occur, treating them in tandem may enhance recovery and reduce the risk of recurrence.”
– Karakuła-Juchnowicz H et al, Feb 2017, Nutr Neurosci.

Though this is considered a category of major depression sufferers, and it’s not clear yet whether it would apply to all patients. Chronic inflammation has also been connected with the progression of depressive symptoms.

Great, but what does inflammation have to do with your diet or gut? Now that we’ve established a connection between depressive symptoms and inflammation, we can look a little deeper.

The Gut / Leaky Gut Syndrome

An unhealthy gut can lead to all kinds of health problems, but a more recently looked into side effect are food intolerances and depressive symptoms. Developing a leaky gut is believed to accelerate or exacerbate food intolerances.

Leaky gut is a condition where the gut wall becomes more permeable. This increased permeability means that larger than usual food molecules can make their way into the bloodstream. This induces IgG food sensitivities. The increase of food-specific IgG antibodies causes a domino effect (put simply) that leads to an increase in inflammation. This brings us right back to the link between depressive symptoms and heightened inflammation. Explaining the importance of gut health in treating major depressive disorder.

What this means for Food Intolerances and Depression

While there has been very little research into the efficacy of using a diet to control MDD, the initial and ongoing research is quite promising. It so far seems that reducing inflammation can be highly effective in reducing symptoms. Methods including avoiding foods which the patient is sensitive to (as indicated through IgG intolerance testing), ingesting anti-inflammatory supplements or foods, and exercising have been found effective for many individuals.