An orange a day may keep blindness at bay. New research reveals that loading up on vitamin C-rich foods can significantly reduce the risk of cataracts, the most common cause of blindness worldwide.
Researchers at King's College in London said the latest findings are important because they are the first to show that diet and lifestyle may be more influential than DNA when it comes to the development and severity of cataracts.
The latest research involved data from 324 pairs of female twins who participated in the TwinsUK cohort study. Participants were asked to answer food questionnaires. Researchers used answers from the questionnaires to track participants' consumption of vitamin A, vitamin B, vitamin C, vitamin D, vitamin E, copper, manganese and zinc. Participants were also asked to undergo digital imaging to check the clarity of their lenses throughout the study.
Study analysis revealed that women who reported eating lots of vitamin C-rich foods were a fifth less likely to have cataracts at the beginning of the study. Further analysis revealed that those who loaded up on vitamin C were also a third less likely to experience cataract progression compared to those who had less vitamin C intake.
After analyzing statistics on heritability, researchers found that genetic factors accounted for 35 percent of the difference between participants when it came to cataract progression. However, environmental factors like lifestyle and diet accounted for 65 percent of difference between participants.
"The best-fitting model estimated that the heritability of nuclear cataract progression was 35 percent, and individual environmental factors explained the remaining 65 percent of variance. Dietary vitamin C was protective against both nuclear cataract at baseline and nuclear cataract progression, whereas manganese and intake of micronutrient supplements were protective against nuclear cataract at baseline only," researchers wrote in the study.
Researchers said the latest findings are surprising because they are the first to suggest that environmental factors are more important than genetic factors at determining the progression of cataracts.
"This is consistent with previous studies showing that heritability generally is lower when examining change, compared with cross-sectional studies. In addition to early developmental differences and the body's response to environmental factors in adulthood, environmentally driven processes or accumulated 'errors' (e.g., somatic gene mutation and epigenetic remodeling) might play a greater role in determining change during aging than genetic factors," they explained in the study.
However, the most important finding from the latest study is that vitamin C can protect eyesight.
"The most important finding was that vitamin C intake from food seemed to protect against cataract progression," said study author Christopher Hammond, professor of ophthalmology at King's College London, according to a news release. "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."
The findings are published in the journal Ophthalmology.
