Until recently, scientists were in the dark about nutrients’ role in preventing eye disease, but that’s no longer the case. A spotlight is shining on several important nutrients and their potential effects on eye health.
It’s a big deal; an estimated 16 million Americans over age 45 have some reported vision loss, with cataracts and age-related macular degeneration (AMD) causing much of the havoc. The lens moves on a path from transparent to opaque in cataract formation. AMD occurs as light-sensitive cells within the retina, particularly in the macula lutea, break down. It is one of the leading causes of blindness and vision impairment among people aged 55 and over.
Eye damage may start out early with exposure to sunlight, as ultraviolet light appears to damage the eye’s lens, and blue light affronts the retina. Free radicals also mount their destruction of the lens over time.
So how do nutrients protect against such assaults on eye health? Scientists have found high levels of vitamins C and E in the lens. These antioxidant nutrients seem to protect protein-digesting enzymes that seek out and destroy damaged and oxidized proteins accumulating on the lens that can lead to cataracts. Scientists have also found that lutein and zeaxanthin are concentrated in the retina. These carotenoids appear to protect the retina by absorbing blue light and neutralizing free radicals.
An eye on research
A number of studies during the past decade have looked at the effects of these and other nutrients on eye health. These found that people with high intakes of vitamins C and E, riboflavin, folate, beta-carotene, lutein, and zeaxanthin experience a lower prevalence of lens opacification than those with lower intakes of the nutrients. In addition, long-chain omega-3 fatty acids from fish are also associated with a decreased risk of advanced AMD. Results from the Age-Related Eye Disease Study (AREDS), published in the Archives of Ophthalmology (2001; 119(10):1,417-36), revealed a 25% lower risk of developing AMD when people took high-dose combinations of vitamins C and E, beta-carotene, and zinc for more than six years.