Cataracts are an opacity of the eye that is most commonly associated with age. The opacity distorts the light entering the eye and this leads to reductions in visual acuity. Studies investigating the development of cataracts suggest that oxidation of the lens of the eye, through the generation of free radicals, is a significant factor. Because the elderly have been exposed to oxidative conditions for longer, this why they have a greater risk of developing cataracts. It is known that oxidation in human tissues can be prevented by antioxidant substances. The antioxidants interfere with the oxidation process and provide significant protection from tissue damage. Some antioxidants such as superoxide dismutase, glutathione peroxidase and catalase are generated inside cells, and these antioxidants are highly important to health. However, many antioxidants are dietary in origin and therefore the diet of the individual may significantly affect the oxidation of tissues, and therefore the development of diseases of oxidation such as cataracts.
Vitamin C supplements may have beneficial effects against the formation of cataracts. This is because vitamin C is an important dietary antioxidant. However, it is likely that diets high in vitamin C are also effective. In fact high quality diets are likely more effective than supplements because diets tend to contain a range of different antioxidants, and these can work synergistically together. A typical high fruit diet can provide upwards of about 600 mg of vitamin C each day. Most supplements contain between 500 and 1000 mg.
Vitamin C (ascorbic acid) is a vitamin and an important dietary antioxidant. Vitamin C has been investigated for its ability to inhibit the development of cataracts and in this regard appear to have significant beneficial effects. For example, in one study, lens opacities were measured in a number of healthy women aged between 56 and 71 years. The results of the study showed that use of vitamin C supplements for over 10 years was associated with a 77 % lower prevalence of early lens opacity, and an 83 % lower prevalence of moderate lens opacity. However, in women who consumed vitamin C for less than 10 years there was no association with reduced opacity. Therefore vitamin C supplements taken over the long term are associated with a reduced prevalence of lens opacity. This supports the contention that dietary antioxidants are beneficial to the health because of their ability to inhibit free radical damage. However, this benefit is only apparent over the long term, highlighting the need for long term dietary discipline.
Eat Well, Stay Healthy, Protect Yourself
RdB
