A steady diet of Pringles chips, French fries, white bread and processed meats may have cost a teenager in the UK their sight, according to a new report.
A case study published on September 2, 2019 in the Annals of Internal Medicine describes a case of nutritional optic neuropathy, a dysfunction of the optic nerve caused by poor nutrition, which led to permanent vision loss in a 17-year-old boy. The disease is usually associated with a deficiency of folic acid and vitamin B complex, according to the National Institutes of Health.
It is surprising that his nerve damage was not reversible, even after being treated with vitamin B12, according to Elizabeth Bradley, MD, the medical director of the functional medicine center at the Cleveland Clinic in Ohio, who was not the author of the article. Although she has “never seen this impairment affect eyesight before”, Dr Bradley says she has “had patients with anorexia who developed irreversible neuropathy in the legs”.
“This case highlights the impact of diet on visual and physical health, and the fact that calorie intake and BMI [body mass index] are not reliable indicators of nutritional status, ”said Denize Atan, MBChB, PhD, the lead author of the study, a bachelor’s degree in medicine and surgery and a consultant lecturer in ophthalmology at Bristol Medical School in England, in a declaration.
First fatigue, followed by loss of vision
The young man went to his GP for the first time at the age of 14, complaining of fatigue. Described as a “picky” eater, the patient (his name has not been disclosed) was of normal weight and height and showed no signs of malnutrition. The labs revealed that he suffered from macrocytic anemia and low levels of vitamin B12 (which can cause anemia). He was sent home after receiving B12 injections and nutritional counseling.
On his next visit, a year later, the patient had signs of hearing loss and changes in his vision, but doctors were unable to identify the cause of the symptoms.
At 17, the boy’s vision had deteriorated to 20/200 in both eyes, considered legally blind in the United States. Further testing revealed that he still lacked vitamin B12, copper, selenium and vitamin D. His zinc levels were high and his bone mineral density was low. Doctors have discovered damage to her optic nerve, which is responsible for sending the images we see from the retina to the brain.
It’s possible that B12 deficiency isn’t just caused by a poor diet, says Bradley. There are people who have a genetic defect that can cause them to have increased needs for vitamins B12, folate or B6, she says.
After doctors discovered the degree of these deficiencies, the boy was prescribed nutritional supplements and referred to mental health services for his eating disorder. Although his vision stabilized, his eyesight did not improve.
Evidence linking unhealthy eating to macular degeneration
Although nutritional deficiencies affect an estimated 2 billion people worldwide, nutritional optic neuropathy is relatively rare, according to the authors. It is caused by a malabsorption of nutrients, certain medications, or a poor diet combined with alcohol abuse or smoking. The condition is potentially reversible if caught early; if left untreated, it leads to permanent blindness.
The link between nutrition and eye health has been established in the existing literature. A study published in July 2014 in the American Journal of Ophthalmology found that an unhealthy diet appeared to increase the risk of age-related macular degeneration (AMD), a condition that leads to blurred vision.
Researchers compared people who ate a greater amount of red meat, processed meat, French fries, refined grains, and eggs to people who ate a plant-based diet high in fruits, vegetables, legumes, grains. whole and seafood.
The lower prevalence of macular degeneration in the healthy diet group led the authors to conclude that “diet plays an important role in the development of AMD and that prevention of AMD may be achievable through intervention. dietetics ”.
A new diagnosis: avoidant-restrictive eating disorder
The teenage patient in the UK case study denied drinking alcohol, tobacco, or using drugs, which may increase his risk for nutritional optic neuropathy. But his diet was severely nutritionally limited. The young man told doctors that starting in elementary school, he would not eat foods with certain textures. His daily diet consisted of fries from a local fish and chip shop, along with Pringles, white bread, slices of processed ham and sausages.
This type of self-imposed food restriction can signal an eating disorder known as Avoiding restrictive food intake disorder (ARFID), formerly known as selective eating disorder.
People with ARFID may avoid foods with certain textures or smells or worry about the consequences of eating, such as choking or even death. Weight loss is common, but people with ARFID can also have a normal weight, as was the case with the teenager in England. The eating disorder can lead to serious medical consequences, including death from cardiac arrest.
American diet: lots of calories but lack of nutrients
The average American consumes about 3,600 calories per day, a 24% increase from 1961, but that hasn’t translated into better nutrition. A study published in July 2017 in Nutrients found that American children and adults have high rates of deficiency of vitamins A, B6, B12, C, D, E and folate, and the mineral iron.
Bradley also sees this phenomenon in his clinic. “We see obese patients suffering from malnutrition. You might think that an overweight or obese person is getting enough nutrients in their diet, but that is often not the case, ”she says.
Even people who eat fruits and vegetables don’t always get the nutrients they need because of poor soil quality, Bradley explains. “The vitamins and minerals in your vegetables are as good as the soil they are produced from,” she explains.