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Second Glance Elmer Friedman, OD
VITAMINS: Do They or Don’t They
PREVENT CATARACTS? CATARACTS ARE A HUGE PROBLEM. Almost one half of persons over 75 years of age will lose some vision because of cataracts. Cataract surgery is the single greatest surgical cost in Medicare. At present there is still no dietary prescription that will predictably reduce the likelihood of developing any type of cataract.
There are different types of cataracts, depending on their location in the lens of the eye. The outermost layer is called the posterior subcapsular cataract. Cataracts in the next layer are called cortical cataracts and the most central location of the lens is called the nuclear cataract. The type that occurs the least is the posterior subcapsular type. This type and the cortical type cataracts were analyzed as to their relation to vitamin supplements and were covered in a 2002 report from the American Journal of Clinical Nutrition. A group of 492 nurses were studied, aged 53 to 73 years, who had been followed for at least seventeen years. Foodstuffs and vitamin uses were investigated many times during the study period.
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This report stated that the number of posterior subcapsular cataracts came to 86 and 248 cortical types of cataracts were determined. The investigators announced that their results found no connection between any antioxidants or vitamins. Furthermore they performed a sub analysis and found that Vitamin C, if taken in dosages of 360 milligrams or more (far over the recommended 70 milligrams daily) reduced the risk of cortical cataracts by almost 60 percent in women under the age of 60. However, among women taking 240 to 360 milligrams, the risk actually appeared to increase to more than double the number. Women under the age of 60 years who were taking Vitamin C containing supplements for at least five years showed a 67 percent reduction in cortical cataracts. But women over the age of 60 years, taking vitamin C supplements for 5 to 9 years, had a doubled risk of cortical cataracts. Another finding was that for those who never smoked cigarettes and increased their total carotenoid intake (alpha and beta carotenes, lycopenes, lutein) – the result was a reduction in posterior subcapsular cataract risk by 66 percent. The reduction was even greater with those with increased folic acid intake (more than 70 percent). The authors concluded that “Our results support a role for Vitamin C in thwarting the risk of cortical cataracts in women less than 60 years of age and for carotenoids which diminished the risk of posterior subcapsular cataracts in women who have never smoked.” Reviewers have commented that many inconsistencies exist. It makes sense that antioxidants could reduce the risk of cataracts because the lens of the eye is exposed to oxidant changes. This is the same chemical process that rusts iron and makes cooking oil turn rancid. In the eye, the oxidative process can occur as part of normal metabolism as well as in the presence of light, which creates harmful unstable molecules called free radicals. These free radicals grasp electrons from your body’s healthy molecules to balance themselves, causing an ever escalating molecular free for all that ends up hurting perfectly innocent cells. The lens can partially protect itself from this free radical damage. It relies on certain nutrients to keep its defense strong. It has been established that vitamins C and E and beta carotene are helpful. The evidence shows that when these nutrients are taken together they work best. In addition to the vitamins mentioned above it is recommended that minerals such as selenium, zinc and copper may all play Continued on page 40