Not everyone is convinced by the case study.
"It's intriguing," say Allen Taylor, the director of the Nutrition and Vision Laboratoryat the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts. "But it's important to remember it's a study of only one case with very limited information in it," Taylor says.
Taylor says he'd like to know more about how the teen ended up with permanent vision loss, given that optic neuropathy is very uncommon and usually temporary.
But he says the case study 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 says, usually people don't develop symptoms until much later in life.
He points to a study he and his collaborators published back in 2014, which found that poor-quality diets can increase the risk of age-related macular degeneration. This can lead to blurry vision and can make reading more difficult. It usually occurs after age 60.
"Conversely, the more one subscribes to a diet rich in fruits and veggies, whole grains, the less the risk for AMD," Taylor says.
People in Taylor's study who consumed plenty of vegetables, legumes, fruits, whole grains, tomatoes and seafood had a lower risk of developing AMD. On the other hand, people who consumed a diet rich in red meat, processed meat, high-fat dairy products, French fries and refined grains had a higher risk of developing the condition.
Taylor says it's important to note that the quality of the carbohydrates you eat really does seem to matter. ( As we've reported, aim for "slow carbs.")
Consuming a lot of refined carbohydrates, including foods such as white bread, chips, crackers and sweets, is linked to a higher risk of developing AMD and some forms of cataracts. Taylor and his collaborators are trying to understand how refined carbohydrates may inflict damage on the cells within our eyes and bodies.
"If you look at the chemistry behind what's going on in the cells, you can actually see the vestiges of the carbohydrates in the cells," Taylor says.
"The carbohydrates end up damaging the proteins within the cells of the eyes," he says, so the proteins are no longer as functional as they might have been.
Taylor's findings are not a huge surprise, given what's known about diet and health overall.
Around the globe, poor diets are a leading contributor to premature death — even more than smoking — and in the U.S., an estimated 1,000 deaths per dayfrom cardiovascular and metabolic diseases are linked to diet. So the idea that diet influences the health of eyes makes sense.
Bottom line: "Be sure to feed yourself and your loved ones a diet that's rich in fruits and vegetables ... and whole grains," Taylor says.
Got more questions about how to eat well? We've got you covered. Check out our LifeKit guide to healthy eating.
