A randomized, placebo-controlled study found that long-term supplementation with vitamin E and/or selenium was unlikely to protect against cataract risk in older men. Published in JAMA Ophthalmology, the study looked at data from 11,267 men with a median age of 61 who initially did not have cataracts. The men received vitamin E (400 IU daily), selenium (200 mcg daily as L-selenomethionine), vitamin E and selenium together, or a placebo.
After 5.6 years, researchers discovered the men didn't experience statistically significant reductions in cataracts or cataract removals. However, here are some important considerations to take into account when evaluating these findings:
Men taking selenium did have a non-significant reduction in cataracts (-9%) and cataract removals (-16%).
According to one ophthalmologist, the clinical significance of this research is likely limited: treating cataracts with vitamin E and selenium is not a mainstream practice, and the results do not alter the fact that other vitamins are known to be helpful for some eye conditions such as macular degeneration.
The type of vitamin E used in the study is not the same as the type that occurs in food. The study used only alpha-tocopherol, whereas vitamin E occurs in food in four different forms: alpha-, beta-, gamma-, and delta-tocopherol. Taking large amounts of alpha-tocopherol by itself (such as 400 IU per day or more) can deplete gamma-tocopherol, a form of vitamin E that has many beneficial effects. The results of the study might have been different if vitamin E had been given in the form of mixed tocopherols, which contain all four forms of the vitamin.
Source: JAMA Opthamology