When it comes to cataracts, your lemons work just as great as your carrots in protecting your eyesight. Not only that, your diet trumps genetics when it comes to influencing cataract progression.
Cataract is a common eye condition characterized by the gradual opaqueness of the crystalline lens, which can lead to vision loss. It affects at least 24 million Americans starting at 40 years old, according to the American Academy of Ophthalmology. Currently, the only treatment available is surgery — which involves the removal of the natural lens and the implantation of an artificial intraocular lens (IOL).
For the study conducted by the King's College London from more than 1,000 female twin pairs, the researchers monitored the nutrient intake including vitamin C of participants through questionnaires.
By the time they reached 60, digital images of their eyes were checked for opacity to measure cataract development, and 10 years after, 324 of these pairs underwent a follow-up.
Based on the result, those who upped their diet with food rich in vitamin C were 20 percent less likely to develop cataracts. The percentage even increased a decade after when their cataract risk reduced to 33 percent.
"The most important finding was that vitamin C intake from food seemed to protect against cataract progression," said Dr. Christopher Hammond, one of the study author and ophthalmology professor at King's College London.
For many years, good eyesight is associated with intake of beta-carotene derived from food such as carrots and eggs, which is converted by the body into vitamin A. This fat-soluble vitamin then improves vision by enhancing the conversion of light into brain signals.
However, this study published in Ophthalmology showed that vitamin C is also effective by slowing the oxidation process that promotes lens clouding.
The study also reflected on the impact of genetics and environment to cataract progression, and the researchers discovered that although genetics still plays a huge role, 65 percent can be attributed to environment such as diet, smoking and diabetes.
Science has not figured out yet how to prevent cataract formation completely, but it may be delayed by consuming foods rich in vitamin C, says Kate Yonova-Doing, the study's first author.
"The human body cannot manufacture vitamin C, so we depend on vitamins in the food we eat. We did not find a significantly reduced risk in people who took vitamin tablets, so it seems that a healthy diet is better than supplements," she added.
Photo: Andrew Comings | Flickr
