The Link Between Anorexia and Gut Health
I have been meaning to write this blog for over a year now, so when my best friend/Associate Registered Nutritionist, Sophie (@sophieshealthykitchen), asked if I wanted to co-write a blog about Anorexia Nervosa and gut health, I jumped at the opportunity. Sophie recently attended a conference at the Royal Society of Medicine in London that discussed the role of diet in mental health. And I wrote my MSc dissertation on this exact topic. So, we combined our research and summarized our findings for you guys!
What is Anorexia?
Often misunderstood as a disorder of vanity, Anorexia Nervosa is the mental health disorder with the highest mortality rate of all psychiatric disorders. It is characterized by extremely low body weight, insufficient food intake and intense fear of weight gain... Anorexia does not discriminate based on age, gender, race, socioeconomic status, etc., but the demographic with the highest prevalence rate in females of 0.4%. As the exact cause remains unknown, treatment is a complex obstacle.
Additionally, what makes treating this disorder so difficult, is the fact that different individuals respond differently to various forms of treatment.
Consequences of anorexia include a range of both physical and psychological side effects. Some of these include malnourishment due to extreme weight loss, feeling tired, faint or dizzy, osteoporosis, digestive issues, and weakened immune system.
What is Gut Health and Why Is It Important?
Gut health seems to be a term that is thrown around a lot these days, as it has become "on-trend" in the media, and for good reason! Our guts are home to billions of bacteria, viruses, and fungi, which have a combined weight of approximately 1kg - fundamentally the same weight as the human brain. The gut microbiome (all the microorganisms and their genetic material) has a strong impact on digestion, immunity, metabolism, as well as mental and brain functions.
A "healthy" gut is described as having a wide range of diversity! On the other hand, a sub-par gut is described as the loss of beneficial microorganisms, the expansion of harmful microorganism, and/or the loss of overall microbial diversity.
The microbes in your gut also communicate with your brain via the "gut-brain-axis". This means the bacteria that inhabit your gut can talk to, and influence your brain regarding mood, stress, and anxiety.
Interestingly, new research is now suggesting that our gut microbiome may be affected and 'altered' by various different factors. We know that antibiotics can have a negative effect on gut health, and it is advised that probiotics are taken alongside them, particularly if taken for a prolonged period of time. A body of research also tells us that our gut loves fiber (found in fruit, veg, and whole grains). In fact, it is recommended that we eat around 30g of fiber a day and the average intake in the UK is only around 18g.
What Does the Research Tell Us About Gut Health In Individuals Who Suffer From Anorexia?
Our gut bacteria are greatly influenced by the foods we eat. Therefore, the lack of food and associated malnutrition can alter the gut microbiome and result in sub-optimal conditions. Here are some negative side effects of Anorexia Nervosa (AN) in relation to the gut:
1. Decreased intestinal wall thickness, which leads to increased permeability of the gut, can increase the risk of infections and inflammation, and cause GI symptoms, such as bloat, pain, and inevitable "leaky gut". This also increases the risk of developing an auto-immune disease.
2. Microbial diversity decreases and the quantity of harmful bacteria increases. For example, those with Anorexia have higher concentrations of M. smithii, which has been shown as an adaptive mechanism in patients with AN to achieve optimal extraction of calories from very low-calorie diets.
3. Dysbiosis (sub-optimal bacteria profile) also exists in those with depression, OCD, and anxiety, all of which are co-morbidities of Anorexia. Additionally, the low mood experienced by those suffering from Anorexia may be due to the poor nutritional intake. Thus, AN may promote low mood, which then contributes to the progression of the disease, which makes treatment more difficult.
4. A gut-healthy diet rich in fermented foods and low in processed foods has been shown to reduce symptoms of stress and anxiety.
5. Recently, however, there has been compelling evidence that the intestinal microbiota may regulate symptoms and maintaining factors of AN, including weight, energy metabolism, immunity, anxiety, and depression. Variations in gut bacteria may be associated with extreme weight loss, thereby perpetuating AN via direct effects on weight and mood.
Why Is This Important
Good gut health is important for digestion and AN sufferers usually experience a lot of digestive discomforts. What we don't know yet is the types of anorexia that may have a more detrimental effect on the gut. More research is needed to identify whether or not gut symptoms are worsened by prolonged periods of food restriction and purging, for example. Although AN behaviors and symptoms differ from person to person, the present research strongly indicates that poor gut health is associated with this mental health disorder and when treating this illness, gut health research should be used as a tool for recovery.
So, the big question remains: Is an altered gut microbiota simply an obvious result of long-term reduced food consumption, potential dietary deficiencies, and weight loss? Or, alternatively, does microbial composition have the potential to cause these metabolic outcomes and possibly, to contribute to disordered eating behavior? We need more large-scale follow-up studies to clarify these relationships. However, this may offer novel ways to treat eating disorders, specifically Anorexia! If you are suffering from disordered eating patterns and digestive issues as a result, please seek help from a qualified professional. Other helpful resources can be found at https://www.beateatingdisorders.org.uk/