Carbohydrates and cataracts

A study published in the most recent issue of the American Journal of Clinical Nutrition presents evidence that a lifetime of high-carbohydrate consumption significantly increases the chances of developing cataracts.
As the article points out, cataracts are the leading cause of blindness:

Results of a nationwide survey of middle-aged and older Americans revealed that blindness is among the most feared age-related impairments. Cataract is the leading cause of blindness worldwide. An estimated 20.5 million Americans aged 40 y (17.2% of that population) have cataract, 6.1 million (5.1%) have pseudophakia or aphakia, and it is predicted that those numbers will rise by 50% within 2 decades. Opacification, or lens clouding, begins months or even years before vision is affected. Consequently, strategies to prevent opacification hold promise for reducing this enormous public health burden.

The study—a part of the ongoing Nurses’ Health Study—showed that those women consuming on average over 200 grams of carbohydrates per day had over twice the likelihood of developing cataracts as those consuming less than 185 grams per day. Here is a case where if a little reduction in carb intake is good, a lot is probably better. So a low-carb diet with around 50 grams or less of carb a day would more than likely slow the development of cataracts even more.
Also of interest was the finding that the quality of the carbohydrate, i.e., the glycemic index, had no affect on cataract development—it was simply the total amount.
The authors summarized:

In summary, carbohydrate intake was positively associated with the odds of early cortical opacities in middle-aged women. Because carbohydrate foods represent the main energy source for humans, understanding the potentially harmful effects of a high-carbohydrate diet on the lens is important and worthy of further study.

Indeed!