Recently, researchers in England released preliminary findings from a twin study that suggests the development of nuclear cataracts may be significantly delayed if the patient eats a diet rich in vitamin C.
The study, “Genetic and Dietary Factors Influencing the Progression of Nuclear Cataract,” was published in Opthomolgy, the journal of the American Academy of Ophthalmology (AAO).
Vitamin C and eye health
According to the American Optometric Association, vitamin C has been known for its supportive role in maintaining the health of the blood vessels in our eyes, as well as slowing the progression of age-related macular degeneration.
For this study, researchers wanted to assess whether the same impact vitamin C has been shown to have on age-related macular degeneration would also be observed in the development of nuclear cataracts, the type of cataracts that are associated with aging. The researchers also looked at vitamin C intake in relation to genetic determinants, to see which had a greater impact on disease development.
To do this, researchers utilized data from the TwinsUK database. This database has 12,000 registered twins, both identical and fraternal, ages 16 to 100, and offers information on their clinical, physiological, behavioral, and lifestyle factors through a self-administered survey the participants complete once or twice a year.
There were data available for 2,054 white female twins that met the researchers’ analysis criteria, which included baseline nuclear cataract data; a food frequency questionnaire that tracks the intake of vitamin C and other micronutrients, including vitamins A, B, D, E, copper, manganese and zinc, completed around the time of their eye examination that consisted of digital imaging used to check the opacity of their lenses at around age 60; with follow-up cataract data available for 324 of the twins.
After analysis of the association between nuclear cataract change and micronutrients such as vitamin C in the study population, the key findings included:
- Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression in this population;
- An individual’s environmental factors, such as dietary intake, had a greater role in nuclear cataract progression over a 10-year period when compared to their genetic factors (65 percent vs. 35 percent).
In an AAO press release about the findings, Dr. Christopher Hammond, M.D., professor of ophthalmology at King’s College London and senior author of the study, stated, “The most important finding was that vitamin C intake from food seemed to protect against cataract progression. While we cannot totally avoid developing cataracts, we may be able to delay their onset and keep them from worsening significantly by eating a diet rich in vitamin C.”
This is the first study to show that a patient’s dietary intake of vitamin C may have more of an impact than their genetics on the development of nuclear cataracts. Confirmatory studies will need to be conducted before the current clinical standards for preventative recommendations will be changed.