Fussy eater’ rendered blind by daily diet of french fries and potato chips
A British teen who took picky eating to the extreme, living on little more than a daily order of fries from his local fish and chip shop and Pringles, is now virtually blind, doctors report in a case highlighting a relatively new eating disorder — “avoidant-restrictive food intake disorder.”
“Popular media have highlighted the risks for poor cardiovascular health, obesity and cancer associated with junk food, but poor nutrition can also permanently damage the nervous system, particularly vision,” his doctors reported Tuesday in Annals of Internal Medicine.
The case — “Blindness caused by junk food diet” — involves an unnamed youth from Bristol who, when he was 14, was taken to his family doctor because he was complaining of feeling tired all the time. He was a “fussy eater,” but otherwise well. His doctor diagnosed macrocytic anemia — abnormally large red blood cells — and low vitamin B12. The boy was treated with B12 injections and encouraged to eat a healthier diet.
A year later, he developed hearing loss and, soon after, began complaining he was having problems seeing. His vision grew worse over the next two years, until he was eventually sent to Bristol Eye Hospital ophthalmologist Dr. Denize Atan, who diagnosed optic neuropathy — damage to the optic nerve.
The teen denied using alcohol, tobacco or drugs; his height and weight were average, his body mass index normal. “However, the patient confessed that, since elementary school, he would not eat certain textures of food,” the team reports.
“He had a daily portion of fries from the local fish and chip shop and snacked on Pringles (Kellogg), white bread, processed ham slices, and sausage.”
The teen’s vitamin B12 shots had lapsed, he had low copper, selenium and vitamin D levels, abnormally high zinc levels, and, alarmingly, he was losing bone.
He was put on nutritional supplements and referred to a mental health expert for his suspected eating disorder. But, while his vision problems stabilized, he now has permanent blind spots in the middle of both eyes. “That means he can’t drive and would find it really difficult to read, watch TV or discern faces,” Atan told the BBC.
“He can walk around on his own though, because he has got peripheral vision.”
Optic neuropathy caused purely by malnourishment is rare in developed countries. It’s potentially reversible, if caught early. Left untreated, it leads to permanent blindness.
Unlike anorexia nervosa, “avoidant-restrictive food intake disorder” isn’t driven by concerns about body image or weight gain. It tends to strike in middle childhood with a sudden lack of interest in food, heightened sensitivity to certain textures and “fear of the consequences of eating,” the Bristol team reported.
In an email to the Post, Atan said the boy’s parents tried to introduce different foods into his diet, but he had an aversion to “certain textures” — essentially, any texture that wasn’t like a French fry or potato chip. AFRID isn’t picky eating. Picky eating tends to peak between ages two and six, children tend to avoid only a certain number of foods and they eventually outgrow the behaviour.
In the case of the boy from Bristol, “When I first met him, I felt he was quite a shy and reserved boy,” Atan said in email. He also didn’t volunteer any information about his diet. “It was only after direct questioning that we learned the full extent of his abnormal eating behaviour.”
He’s now 19 and studying information technology, but is registered as having sight impairment and can’t drive due to his vision.
The body’s cells need a variety of nutrients to function normally. “Initially, they may struggle to function with depleted supplies but eventually they will die,” Atan said.
The problem with nerve cells in the optic nerve is that they can’t repair or regenerate, she said, so any nerve loss is permanent.
The boy had followed a restrictive diet for four years before he developed symptoms. “So, problems take a long time to develop,” Atan said. Although he wasn’t formally diagnosed, she suspected avoidant-restrictive food intake disorder, or ARFID, a new category of eating disorders that, in 2013, was added to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. It expanded on what was previously known as “feeding disorder of infancy or early childhood.”
However, fussy eating that’s severely restricted to cheap, nutritionally empty junk foods and that causes multiple vitamin deficiencies is an eating disorder, and children should be seen by a doctor, Atan and colleagues caution.
“Nutritional optic neuropathy should be considered in any patient with unexplained vision symptoms and poor diet, regardless of BMI,” they added.
Writing in The Conversation, Atan warned that recent trends could cause nutritional optic neuropathy to become more common.
“For example, the widespread consumption of junk food at the expense of more nutritious food and the rising popularity of veganism can lead to vitamin D and B12 deficiencies, because fish, meat, eggs and dairy are the main dietary sources of these vitamins,” she said.
“Without nutrient supplements or fortified foods, strict veganism can lead to irreversible blindness.”
According to a recent Dalhousie University study, about 830,000 Canadians label themselves vegan.
“My concern is that some people might decide to omit meat from their diet to become healthier and follow the recent trend in veganism, when their diet with meat in it was not very good anyway,” Atan told the Post.
“Technically, someone who only eats chips and crisps is vegan — so, too, would be someone who eats only rice and pasta and so on, but these are not examples of healthy diets.”
Of course, it is perfectly possible to be healthy on a vegan diet that’s plant-based and includes a variety of fruit and vegetables, nuts, seeds and grains, Atan said. “But this still needs to be supplemented with B12 in particular, as animal products are the main source of B12.”
Suitable sources of B12 would be nutritional yeast, marmite and fortified foods, like fortified cereals and nut milks.