A case study published September 2, 2019, in the Annals of Internal Medicine describes a case of nutritional optic neuropathy, a dysfunction of the optic nerve caused by improper diet, that led to permanent vision loss in a 17-year-old boy. The condition is usually associated with a folic acid and vitamin B complex deficiency, according to the National Institutes of Health. It’s surprising that his nerve damage was not reversible, even after he was treated with vitamin B12, according to Elizabeth Bradley, MD, the medical director of the Cleveland Clinic’s center for functional medicine in Ohio, who was not an author of the paper. While she has “never seen this deficiency impact eyesight before,” Dr. Bradley says that she had “patients with anorexia who have developed neuropathy of the legs that was irreversible.” “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 study’s lead author, a bachelor of medicine and surgery, and a consultant senior lecturer in ophthalmology at Bristol Medical School in England, in a statement.

First Fatigue, Followed by Loss of Vision

The young man first visited his general practitioner at the age of 14, complaining of tiredness. Described as a “fussy” eater, the patient (his name was not released) had a normal weight and height and showed no signs of malnutrition. Labs revealed he had macrocytic anemia and low vitamin B12 levels (which can cause anemia). He was sent home after receiving B12 injections and nutritional counseling. At his next visit, one year later, the patient had signs of hearing loss and changes in his vision, but doctors couldn’t pinpoint the cause of the symptoms. By age 17, the boy’s vision had deteriorated to 20/200 in both eyes, considered legally blind in the United States. Additional tests revealed he was still deficient in vitamin B12, copper, selenium, and vitamin D. His zinc level was high, and his bone mineral density was low. Doctors found damage to his optic nerve, which is responsible for sending the images we see from the retina to the brain. It’s possible that the B12 deficiency was not only caused by a poor diet, says Bradley. There are people who have a genetic defect that can cause them to have increased demands for vitamins B12, folate or B6, she says. Once 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 Diet and Macular Degeneration

Although nutritional deficiencies affect about 2 billion people around the world, nutritional optic neuropathy is relatively rare, according to the authors. It’s caused by malabsorption of nutrients, certain drugs, or 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 existing literature. A study published in July 2014 in the American Journal of Ophthalmology found that an unhealthy diet seemed to increase the risk of age-related macular degeneration (AMD), a condition that leads to blurry vision. Researchers compared people who ate a higher 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, whole grains, and seafood. The lower prevalence of macular degeneration in the healthy-eating group led the authors to conclude that “diet plays an important role in the development of AMD and that the prevention of AMD may be achievable through dietary intervention.”

A New Diagnosis: Avoidant-Restrictive Food Intake Disorder

The teen patient in the UK case study denied drinking alcohol, smoking, or using drugs — all of which could increase his risk for nutritional optic neuropathy. But his diet was severely limited nutritionally. The young man told doctors that beginning in elementary school he would not eat foods with certain textures. His daily diet consisted of fries from a local fish-and-chip shop, as well as Pringles, white bread, and processed ham slices and sausage. This type of self-imposed food restriction can signal an eating disorder known as avoidant restrictive food intake disorder (ARFID), formerly called selective eating disorder. People with ARFID may avoid foods with certain textures or smells or be concerned about the consequences of eating, such as choking or even death. Weight loss is common, but people with ARFID can be in the normal weight range as well, as was the case with the teen in England. The eating disorder can lead to serious medical consequences, including death by cardiac arrest.

U.S. Diet: Lots of Calories but Nutritionally Lacking

The average American consumes about 3,600 calories a day, a 24 percent increase from 1961, but that hasn’t added up to better nutrition. A study published in July 2017 in Nutrients found that U.S. children and adults have high deficiency rates in vitamins A, B6, B12, C, D, E, and folate, and the mineral iron. Bradley sees this phenomenon in her clinic as well. “We are seeing obese patients who are malnourished. You may think someone who is overweight or obese is getting enough nutrients in their diet, but that’s often not the case,” she says. Even people who eat fruits and vegetables don’t always get the nutrients they need because of the low quality of the soil, says Bradley. “The vitamins and minerals in your vegetables are only as good as the soil they’re being produced from,” she explains.


title: “Junk Food Diet Linked To Teen S Blindness” ShowToc: true date: “2022-12-26” author: “Carol Morey”


A case study published September 2, 2019, in the Annals of Internal Medicine describes a case of nutritional optic neuropathy, a dysfunction of the optic nerve caused by improper diet, that led to permanent vision loss in a 17-year-old boy. The condition is usually associated with a folic acid and vitamin B complex deficiency, according to the National Institutes of Health. It’s surprising that his nerve damage was not reversible, even after he was treated with vitamin B12, according to Elizabeth Bradley, MD, the medical director of the Cleveland Clinic’s center for functional medicine in Ohio, who was not an author of the paper. While she has “never seen this deficiency impact eyesight before,” Dr. Bradley says that she had “patients with anorexia who have developed neuropathy of the legs that was irreversible.” “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 study’s lead author, a bachelor of medicine and surgery, and a consultant senior lecturer in ophthalmology at Bristol Medical School in England, in a statement.

First Fatigue, Followed by Loss of Vision

The young man first visited his general practitioner at the age of 14, complaining of tiredness. Described as a “fussy” eater, the patient (his name was not released) had a normal weight and height and showed no signs of malnutrition. Labs revealed he had macrocytic anemia and low vitamin B12 levels (which can cause anemia). He was sent home after receiving B12 injections and nutritional counseling. At his next visit, one year later, the patient had signs of hearing loss and changes in his vision, but doctors couldn’t pinpoint the cause of the symptoms. By age 17, the boy’s vision had deteriorated to 20/200 in both eyes, considered legally blind in the United States. Additional tests revealed he was still deficient in vitamin B12, copper, selenium, and vitamin D. His zinc level was high, and his bone mineral density was low. Doctors found damage to his optic nerve, which is responsible for sending the images we see from the retina to the brain. It’s possible that the B12 deficiency was not only caused by a poor diet, says Bradley. There are people who have a genetic defect that can cause them to have increased demands for vitamins B12, folate or B6, she says. Once 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 Diet and Macular Degeneration

Although nutritional deficiencies affect about 2 billion people around the world, nutritional optic neuropathy is relatively rare, according to the authors. It’s caused by malabsorption of nutrients, certain drugs, or 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 existing literature. A study published in July 2014 in the American Journal of Ophthalmology found that an unhealthy diet seemed to increase the risk of age-related macular degeneration (AMD), a condition that leads to blurry vision. Researchers compared people who ate a higher 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, whole grains, and seafood. The lower prevalence of macular degeneration in the healthy-eating group led the authors to conclude that “diet plays an important role in the development of AMD and that the prevention of AMD may be achievable through dietary intervention.”

A New Diagnosis: Avoidant-Restrictive Food Intake Disorder

The teen patient in the UK case study denied drinking alcohol, smoking, or using drugs — all of which could increase his risk for nutritional optic neuropathy. But his diet was severely limited nutritionally. The young man told doctors that beginning in elementary school he would not eat foods with certain textures. His daily diet consisted of fries from a local fish-and-chip shop, as well as Pringles, white bread, and processed ham slices and sausage. This type of self-imposed food restriction can signal an eating disorder known as avoidant restrictive food intake disorder (ARFID), formerly called selective eating disorder. People with ARFID may avoid foods with certain textures or smells or be concerned about the consequences of eating, such as choking or even death. Weight loss is common, but people with ARFID can be in the normal weight range as well, as was the case with the teen in England. The eating disorder can lead to serious medical consequences, including death by cardiac arrest.

U.S. Diet: Lots of Calories but Nutritionally Lacking

The average American consumes about 3,600 calories a day, a 24 percent increase from 1961, but that hasn’t added up to better nutrition. A study published in July 2017 in Nutrients found that U.S. children and adults have high deficiency rates in vitamins A, B6, B12, C, D, E, and folate, and the mineral iron. Bradley sees this phenomenon in her clinic as well. “We are seeing obese patients who are malnourished. You may think someone who is overweight or obese is getting enough nutrients in their diet, but that’s often not the case,” she says. Even people who eat fruits and vegetables don’t always get the nutrients they need because of the low quality of the soil, says Bradley. “The vitamins and minerals in your vegetables are only as good as the soil they’re being produced from,” she explains.