Taking high-dose vitamin C dietary supplements may boost womenâ€™s chances of developing age-related cataracts, a new Swedish study suggests.
The study from researchers at the Karolinska Institutet in Stockholm said in some cases, women taking the tablets were at least 25 percent more likely to have age-related cataracts than women who did not take the supplements, according to a Reuters news report.
The study findings appear in the latest issue of the American Journal of Clinical Nutrition.
The study focused on about 24,600 women who were followed for longer than eight years. Women who used vitamin C supplements of about 1000 milligrams regularly or occasionally were at increased risk of suffering the eye condition, the researchers said.
Women who took the extra vitamin C for 10 years or longer, were 65 years or older, or were also taking hormone replacement or corticosteroid drugs were at even greater risks, the study found.
Keep Eating Those Fruits and Veggies
So thatâ€™s the bad news. But the good news is, the study suggests the increased cataracts risk is only associated with vitamin C from dietary supplements, not that derived from fruits and vegetables. Previous studies have found similar links between high-dose vitamin C supplements and increased cataracts risk.
Millions of women take vitamin C supplements to fight against colds and other infections and for other health benefits. However, the new Swedish study suggests curtailing the use may be a good idea.
Older Women At Greatest Risk
In the study group, 59 percent of the 49 to 83 year old otherwise healthy women said they used some sort of dietary supplement. Of these women, five percent said they only took vitamin C supplements and nine percent said they took only multivitamins that contained about 60 milligrams of vitamin C, according to Reuters.
Of the 1,225 women who took only vitamin C supplements, 143 (about 13 percent) had cataracts removed during the study period. In contrast, cataracts were removed in 878 of 9,974 women who did not use any supplements (roughly nine percent) and in 252 of 2,259 multivitamin-only users (about 11 percent).