All About Cataracts

Carnosine, a dietary supplement available without a prescription, may be able to prevent or treat cataracts, according to a study published in the July 14 issue of the American Chemical Society journal Biochemistry.

If true, taking daily supplements of carnosine may reduce the risk of developing cataracts, decreasing the need for cataract surgery.

Carnosine is a small molecule composed of two amino acids. It is found in relatively high concentrations in several body tissues, including muscles, nerves and the brain. The exact role of carnosine in the body is not fully understood but it appears to have an antioxidant effect.

The researchers exposed tissue cultures of lenses taken from healthy rat eyes to either guanidine — a substance known to form cataracts — or a combination of guanidine and carnosine. The lens tissue exposed to guanidine became completely cloudy, while the lens tissue exposed to guanidine and carnosine developed 50 to 60 percent less cloudiness. Carnosine also restored clarity to clouded lens tissue.

Cataracts occur when the primary structural protein in the eye’s lens, alpha-crystallin, forms abnormal clumps. These clumps make the lens cloudy and impair vision. Carnosine appears to play a role in blocking the formation of these clumps and/or reversing them.

Though further research is needed, the findings of the study prompted the researchers to suggest that carnosine could potentially prevent and treat cataracts in humans.

Source: Protective effects of l- and d-carnosine on a-crystallin amyloid fbril formation: Implications for cataract disease. Biochemistry. Published online July 14, 2009.

The connection between nutrition and eye health is receiving plenty of study these days, as researchers are looking for ways people can lower their risk of age-related vision loss with eye vitamins or other nutritional means.

A new study published in the February 2009 issue of Current Eye Research suggests vitamin C may be a key to lowering the risk of the most common type of cataracts.

Researchers in Iran compared blood plasma levels of ascorbic acid (vitamin C) in age- and sex-matched populations of people with age-related cataracts and those without cataracts. Analysis of the data revealed that plasma levels of vitamin C among the subjects with cataracts were significantly lower than plasma levels of the antioxidant vitamin among those without cataracts.

The study also found that plasma levels of ascorbic acid declined with age among men, but not among women. Also, plasma levels of vitamin C were higher among people living in rural settings versus in cities, and women tended to have higher levels of this antioxidant vitamin in their blood than men did.

The researchers concluded that antioxidant vitamins, particularly vitamin C, “can help with the prevention of cataracts, which is a major health service burden in many countries.”

Vitamin C and other antioxidant vitamins are found in many fruits and vegetables, as well as in most vision supplements.