Want to delay that date with your cataract surgeon? Add lots of vitamin C-rich foods to your diet, like orange juice, broccoli, peppers and kiwi.
After looking at data from more than 1,000 pairs of female twins in the United Kingdom, researchers there have concluded that vitamin C-rich foods — but not supplements — may be one key to avoiding the common eye condition and, once it occurs, stalling its progression.
Cataracts, a clouding of the eye’s nature lens, are common, with more than 40% of people over age 75 affected. Surgery is effective, but like any operation, it involves risks.
In the British study, the twins who had been consuming the most vitamin C-rich food, compared to those who’d taken in the least amount, had a 20% lower risk of having cataracts at the start of the study.
The researchers examined the women’s eyes for cataracts at around age 60, then did follow up measurement on some 650 of the original women a decade later. In the follow-up, those who’d eaten the most vitamin C-rich foods had a 33% reduced risk of cataracts progressing.
Why Does Vitamin C in Food Lower Cataract Risks?
Christopher Hammond, MD, professor of ophthalmology at King’s College London, who led the study, credits vitamin C’s antioxidant property for helping to guard against cataract development and progression.
“We know that loss of lens clarity is due to oxidation of lens proteins,” he says. So high levels of vitamin C bathing the lens reduces that oxidative stress.
Why don’t supplements work? “The lack of protection from supplements suggests there may be other factors in the healthy diet that are also reducing aging in the lens and elsewhere,” Hammond says.
How Much Vitamin C Is Enough?
“Good question and one that we have not fully calculated,” Hammond says. He does know that those in the group of women who got the most protection took in more than 160 milligrams a day of vitamin C from foods and drink. In his study, the median amount of vitamin C (half of the study participants ate less) taken in daily was 120 milligrams, or twice what is recommended in the UK.
The recommended amount of vitamin C daily in the US is 75 mg for adult women and 90 mg for adult men. To put that in context, an orange has 70 mg and a half cup of sweet red pepper has 95 mg. Eating just those two foods, or the equivalent, would put you in the highest intake group tested by Hammond.
Genetics vs. Lifestyle
What about the role of genes — in other words, if your mother had cataract surgery, does that mean you will? In his research, Hammond concluded that the genetic factor accounted for only 35% of the difference in cataract progression, and diet and other environmental factors accounted for the other 65%.
So apparently you can outwit your genes — in some cases, at least.
The study is published in the journal Ophthalmology.
Have you had cataract surgery, or has your doctor told you that you’ll need it in the future?