Antioxidants not only help prevent some eye diseases, they may also help limit progression of the diseases
It’s known that taking antioxidants helps delay the onset of some eye diseases associated with aging, such as cataract. Now researchers believe that antioxidants can be effective if damage to retinal tissue has already set in.
Researchers at the University of Maryland School of Medicine studied the effects of reactive oxygen species (ROS)-induced damage to retinal tissue. An increase in ROS levels can result in significant damage to cell structures — a situation known as oxidative stress. Oxidative stress is a significant risk factor in the development of many eye diseases associated with aging.
Since the formation of cataract is a well-defined progressive disease, believed to be related to a continued generation of ROS in the aqueous humor, the researchers hypothesized that even a late start with an appropriate antioxidant could halt the process and delay cataract development and vision impairment.
The results? Adding pyruvate — known to be an effective ROS scavenger — to lens cultures after lenses had sustained 50% damage was significantly effective in preventing progress.
Pyruvate can be found in foods such as red apples, and to a lesser extent, in dark beer and some cheeses.
SOURCE: “Oxidative damage to lens in culture: reversibility by pyruvate and ethyl pyruvate”, Varma, et al, Ophthalmologica, 2008; 222 (3):194-198.
Update: More Evidence on Antioxidants & Cataract
Cataracts are the leading cause of blindness around the world. Studies suggest that oxidation is responsible for much of the damage to the lens and that antioxidants might protect the lens against formation of cataract.
Scientists at the University of Sydney and the University of Melbourne in Australia have released their investigation of the relationship between antioxidant nutrient intakes and the incidence of age-related cataract.
During 1992–1994, 3654 people aged 49 years or older attended baseline examinations as part of the Blue Mountains Eye Study. Of these, 2464 (67.4%) of the participants were evaluated again at either 5 years or 10 years. At each examination, lens photography was performed and food-frequency questionnaires were administered. Antioxidants, including beta-carotene, zinc, and vitamins A, C, and E, were assessed. Cataract was assessed at each examination from lens photographs with the use of the Wisconsin Cataract Grading System.
Participants whose total intake of vitamin C (diet as well as supplements) was in the top 20% of the group had a reduced risk of nuclear cataract. An above-median intake of combined antioxidants (vitamins C and E, beta-carotene, and zinc) was also associated with a reduced risk of incident nuclear cataract.
Study authors concluded that higher intakes of vitamin C or the combined intake of antioxidants had long-term protective associations against development of nuclear cataract in this older population.
SOURCE: Tan, et al, Antioxidant nutrient intake and the long-term incidence of age-related cataract: the Blue Mountains Eye Study, American Journal of Clinical Nutrition, Vol. 87, No. 6, 1899-1905, June 2008.