Spitballing With Scientists: Identifying The Eating Disorder Genes

Spitballing With Scientists: Identifying The Eating Disorder Genes

Trigger warning: Disordered eating.

Maybe you’re born with it. Maybe it’s anorexia nervosa, and you were also born with it. Did you know that alongside environmental influences, eating disorders are significantly predisposed by your genetics? I didn’t, but it sure would have saved a lot of guilt and confusion if I had. The Eating Disorders Genetics Initiative (EDGI) is the world’s largest ever genetic investigation into eating disorders. They use human saliva to identify these specific genes and direct future research into illness prevention. 

Eating disorders are usually classified into anorexia nervosa, binge eating disorder (BED), bulimia nervosa, or the wordy Eating Disorder Not Otherwise Specified (EDNOS). These can stand alone, or otherwise coexist in a nightmarish Venn diagram. 

While anorexia nervosa has the highest mortality rate of any psychiatric illness, all eating disorders can be life threatening. Many extremely ill sufferers appear otherwise healthy. Plenty of eating disorders are borne from reasons other than body dissatisfaction. For example, they can be a form of control over a hectic life. Sufferers can be any age, gender, ethnicity, body shape or sociocultural status. A higher-weight, middle-aged bloke in cargo shorts who regurgitates his dinner in private can be at just as much risk as anybody else. 

Martin is a geneticist and Jenny is a clinical psychotherapist. Both are in the process of recruiting thousands of participants for the University of Otago EDGI study. “Whether you're talking about diabetes, schizophrenia, asthma, bulimia nervosa or whatever, there’s always a genetic and environmental component that influences your risk of the condition,” said Martin. “In the case of anorexia nervosa, the majority of the risk is genetic. It’s less genetic for bulimia or binge eating disorder. I hasten to add that it’s never going to be one gene — it’s going to be many genes, probably hundreds of genes. Each gene will have a very small effect on risk.”

Only a few of these eating disorders genes have been identified so far, leaving many more to be found. Martin said that “the reason we want to find these genes is because it reflects the biology that underlies the condition, and we really don't know anything about the biology. When someone develops an eating disorder like anorexia nervosa, they’re tapping into some part of their biology that's almost like an addiction. What's going on there? What's driving that? It's not just a behavioural thing or choice. We think it is being somewhat driven by the biochemical pathways that differ between individuals.”

In their previous study on anorexia nervosa, Martin and Jenny learned that there are metabolic aspects to eating disorders. Anorexics are hardwired to have lower weight since birth. Their metabolism, lipid profiles, fasting sugar, glucose levels and insulin are also slightly different to non-anorexics. 

EDGI was established during Aotearoa’s lockdown in March, when the number of sufferers requiring specialist services increased by four times the average. Many students flatting alone struggled with food insecurity, panic buying, and social solitude. Anxiety levels soared. Life had no structure anymore. 

Under these conditions, eating disorders worsened, re-appeared, or even emerged for the first time. Disordered eating habits are thriving in isolation. On the other hand, students stuck at home weren’t able to hide their habits from families as easily as before. Eating disorder support services, such as EDANZ, were flooded.

“The Covid-19 pandemic has definitely generated an increase in eating disorder resentations and relapses,” EDANZ says. “We experienced a significant increase in contact from families and individuals needing support and advice. This huge demand has continued since the beginning of last year. We have struggled to cope.”

Many of us lived vicariously online throughout lockdown, but as time progressed the Mamma Mia! (2008) Zoom parties lost their novelty. Memes and weight loss articles cropped up about the ‘quarantine 15,’ alluding to the 15 pounds gained by stress-eating at home. Instead of the internet being a form of escapism, some users were bombarded with triggering messages about BMI and Covid risk factors. In one student’s case, not even her online lectures were safe. Her professor asked which students had gained weight during quarantine, completely unrelated to the class, which was an uncomfortable and triggering experience. 

Jenny explains that “many support services stopped assessments or had to switch to Zoom, so the service provision wasn’t business as usual. More delays and general stress impacted students' lives. It was a very different experience to normal campus life. I think it was a pretty tough time for people, and lockdown tipped over that vulnerability. When everyone is exposed to the same social pressures, most people don't develop an eating disorder, but for people with those vulnerabilities, they just keep on going. They’re also more prone to relapse afterwards.”

Sophie had recently begun eating disorder treatment at Student Health when Covid-19 hit, meaning her counselling was suddenly moved online. She made the decision to go home to her family. “It was weird having a Zoom session about my counselling while my parents are in the other room,” she laughed. 

Eating disorder treatment is often as physical as it is mental, imposing unique obstacles in online counselling. “Every single week I’d get weighed. It was weirder during lockdown. I’d be on Zoom and [the counsellor] would be like, do you wanna weigh yourself? So I’d go to the bathroom, weigh myself, and come back.” Although she offered, Sophie did not need to provide proof of her weight. She was prescribed various challenges while at home, such as covering up her mirrors for a week, as well as writing daily food and mood diaries. “One of my challenges is that I had to eat pasta for lunch and dinner for a week until I stopped being scared of it — something I really had to talk to my family about, since I couldn’t hide it. I had to go to my mum and be like, oh, can you buy a bunch of noodles and pasta? It’s weird. You don’t really talk about your counselling a lot to other people.” 

Sophie points out that having irregular eating patterns are normalised in student culture. “I found it easier to hide my eating disorder when flatting than when was at home,” she says. “When flatting, it’s easier to say I’m not eating a lot because I’m too busy, or because I’m drinking. Everyone’s in and out, so you can say you’ve had dinner when you haven’t. When you’re in lockdown, you’re with everyone all the time.”

I decided to give EDGI’s trial a go. I’ve experienced an eating disorder but, like thousands of others around the country, it was not deemed dire enough to receive adequate medical treatment. (All eating disorders are serious, but this is an unfortunately common misconception in our medical system.) The trial began with a screening questionnaire to test my eligibility followed by a more in-depth survey asking me a range of questions. Have I ever experienced a traumatic event? Do I obsessively check if the stove is left on? If I do not set the highest standards for myself, am I likely to end up a second rate person? While I poured my heart out to a computer screen, EDGI researchers were busy sending a saliva kit to my home in order to receive a genetic sample. My little tube of spit would later travel across the world and be processed for gene variations in a biorepository. Godspeed.

How will my mouth goop help contribute to future treatment? Martin compares it to treating cancer or diabetes. “Once we identify the genes and understand the underlying biology, we can target the molecular pathways that those genes operate in, leading to better drug treatment. We could develop better non-drug treatments, too, and prevent somebody in the early stages of an eating disorder from getting worse,” he said. Jenny says that eating disorder treatment hasn’t changed since we first identified the disease in 1875. She hopes that identifying eating disorder genes will help people to rationalise, reducing stigma and shame, and realise that sufferers aren’t doing this on purpose. 

While genes play a role in eating disorders, it doesn’t mean that you’re biologically doomed. Eating disorders can often feel agonizingly incurable. Our country’s resources are horribly inaccessible and it’s far harder to receive treatment than it ought to be. EDANZ echoes this, stating that they are “very concerned about the lack of access to evidence-based treatment for individuals and their families. Too many are suffering longer and more serious illnesses because specialist treatment provided by DHBs is inadequate and does not meet the need [in the community].” GPs need the education and knowledge to identify and support treatment. 

However, EDANZ also emphasises that eating disorders are treatable; that “full, lasting recovery from an eating disorder is possible at any stage and any age.” Ideally, with EDGI’s research, we can learn more about improving treatment and saving lives. One tube of spit at a time. 


If you would like to take part on EDGI’s trial, visit their website at edgi.nz.          

If you or somebody you know needs support:

This article first appeared in Issue 2, 2021.
Posted 9:23pm Saturday 6th March 2021 by Asia Martusia King.