Bloomberg / Bloomberg via Getty Images
A 14-year-old boy goes to the doctor with complaints of fatigue. He is an extremely picky eater. (Think of a daily diet of fried potatoes, plus a breakfast of Pringles potato chips, white bread and a little processed pork.) But overall it looks OK. He is not overweight and does not take medication.
Tests show that he has low levels of vitamin B12 and anemia, so he was given B12 injections and diet tips. But a year later, he began to lose his sight. Then, at 17, he was legally blind.
It turns out that the boy's severely restricted daily diet – lack of healthy foods, vitamins and minerals – has led to optic neuropathy. This is the conclusion of researchers at the University of Bristol, England, who published a case in Annals of Internal Medicine.
"This case highlights the impact of diet on visual and physical health and the fact that calorie intake and BMI are not reliable indicators of nutritional status," said Dr. Deniz Atan, lead author of
Not everyone is convinced by the case.
"It's intriguing," said Alan Taylor, director of the Nutrition and Vision Laboratory at the Human Nutrition Research Center. Jean Mayer USDA on Aging "But it's important to remember that it is only a case study with very limited information in it," Taylor says.
Taylor says he would like to know more about how the teenager ended up with a permanent loss vision, given that optical neuropathy is very rare and usually temporary.
But he says the case could serve as a wake-up call to remind people of the importance of good nutrition.
"There is absolutely a link between poor diet and vision loss," Taylor explains. But he usually says that people don't develop symptoms until much later in life.
He cites a study he and his associates published in 2014, which found that poor-quality diets could increase the risk of age-related macular degeneration. This can lead to blurred vision and may impede reading. It usually occurs after age 60.
more subscribed to a diet rich in fruit and vegetables, whole grains, the lower the risk of AMD, "says Taylor.
The people in the Taylor study who consumed a lot of vegetables, legumes, fruits, whole grains, tomatoes and seafood had more low risk of developing AMD On the other hand, people who consumed a diet rich in red meat, processed meat, high-fat dairy products, fried potatoes and refined grains had a higher risk of developing this state.
Taylor says it's important to note that the quality of the carbohydrates you eat really matters. (As we reported, the goal is "slow carbs.")
Consumption of many refined carbohydrates, including foods such as white bread, chips, crackers and sweets, is associated with a higher risk of developing AMD and some forms of cataracts. Taylor and his associates are trying to understand how refined carbohydrates can cause damage to cells in our eyes and bodies.
"If you look at the chemistry behind what's going on in the cells, you can actually see the carbohydrate residue in the cells," Taylor says.
" Carbohydrates end up damaging proteins in the cells of the eye," he says, so proteins are no longer as functional as they could be.
Taylor's findings are no great surprise, given what is known about diet and health in general.
Worldwide, poor diets are a leading factor in premature death – even more than smoking – and in the USA, approximately 1000 deaths per day of cardiovascular and metabolic diseases are related to diet. So the idea that diet influences eye health makes sense.
Bottom line: "Remember to feed yourself and your loved ones a diet rich in fruits and vegetables … and whole grains," Taylor says.  Have more questions about eating well? We cover you. See our LifeKit Healthy Eating Guide .