Ample lutein, balanced vitamin intake invaluable to AMD, cataract patients

Issue: October 1999

For many older patients, developing cataracts and age-related macular degeneration (AMD) is a frightening experience. Particularly in the case of AMD, patients may feel powerless and frustrated with the disease, which is slowly chipping away at their visual acuity.

However, researchers say that sufferers may have some control over the degenerative changes taking place in the macula. Practitioners suggest recommending supplements and diet modification, adding dark, leafy vegetables, which include carotenoids, specifically lutein. Consumption of vegetables such as spinach, kale and collard greens can halt or even reverse AMD and even nuclear cataract in the early stages, suggest some practitioners.

Stuart P. Richer, OD, PhD, FAAO, chief of optometry at the DVA Medical Center in North Chicago is currently participating in a placebo-controlled, double-masked randomized trial of lutein and antioxidant supplementation. He supports recommending a diet rich in dark, leafy vegetables. “We’ve accumulated about 40 cases, and approximately 80% of the people we place on spinach alone, four times a week, tend to improve,” said Dr. Richer, who presented supporting data at the Association for Research in Vision and Ophthalmology (ARVO) meeting in Ft. Lauderdale, Fla. “From a patient perspective, I’m fairly confident recommending spinach to people as long as they’re not on anything that’s going to thin the blood, such as Coumadin (crystalline warfarin sodium, DuPont), vitamin E or ginkgo biloba.”

The vitamin K found in leafy vegetables such as spinach can sometimes be problematic, Dr. Richer noted, if a patient is taking agents to thin the blood, because this particular vitamin promotes blood clotting. This may be an indication for a lutein-based antioxidant supplement.

Dietary changes

There are a number of other vegetables full of lutein-packed carotenoids that can be added to one’s diet. Benjamin C. Lane, OD, FAAO, FCOVD, director of Nutritional Optometry Associates in Lake Hiawatha, N.J., adds broccoli, cauliflower, cabbage and winter squash to the list for total carotenoid intake. Dr. Lane added that the more spinach, kale and collard greens a person consumes, the better it is to eat organic rather than pesticide treated and preserved. “If we only eat a small quantity, it’s not too critical,” he said. “But if we eat a lot, we want to keep down the pesticide accumulation.”

In conflict with what much of the establishment believes, Dr. Lane said, there are at least two types of maculopathy that begin as the “dry.” One type, as characterized by the presence of only hard drusen, is truly dry, “atrophic” and likely to remain dry unless there is a change in dietary lifestyle. A second type, characterized by at least some “soft” drusen, may not yet be leaking but is at high risk of leaking and becoming “wet,” or “exudative.” This second type is strongly associated with excessive intake of well-cooked protein and excessive accumulation of transaminase enzymes in red blood cells, Dr. Lane explained. “Exudative is reversible with dietary change,” he said.

In addition to beer drinking, deficiency in vitamin B-6, he said, may be a factor in the development of the wet form of AMD. The vitamin, found abundantly in protein, is easily destroyed by heat and is, therefore, lost by overcooking. “We find that even better than just supplying vitamin B-6, even though that helps somewhat, is to reduce protein intake, especially denatured protein,” he said. “When we cook meat to well-done, more of the vitamin is lost. If we lose the larger part of vitamin B-6, we cannot metabolize the protein as well as we would like to.”

Determining supplementation

Vitamins are typically recommended for patients suffering from the dry form of AMD, said Christopher Quinn, OD, in private group practice in Iselin, N.J. The broad spectrum antioxidants in a multivitamin benefit patients more than large doses of specific vitamins, he said, which can actually have an adverse effect. “There definitely are potential problems with using mega doses of vitamins, especially the fat-soluble vitamins,” he said. “They can accumulate in the body, whereas it is difficult to overdose on water-soluble vitamins. A few years ago, we learned about the possible benefit of zinc, but you can overdose on zinc as well. As with most therapies, I think moderation is always the best course of action.”

Zinc, as well as antioxidants, may be an important link to treating the atrophic form of AMD, Dr. Lane said. He suggested first testing the patient for zinc or copper deficiency, then prescribing accordingly. Taking too much zinc may prevent the absorption of copper and vice versa, he said, and an overload of vitamin C can also produce negative effects. “The people who take vitamin C all day long, because they feel the need to have a constant infusion of it, become unable to absorb dietary minerals such as copper and chromium, which are essential nutrients,” he said. “That’s not a problem if they have this habit for a few days or a few weeks, but after several weeks and months they become deficient in the storage of nutrients. Balance is the key. When people go to this extreme, we find that they measure a low level of superoxide dismutase.”

An excess of vitamin C may also contribute to vitreous-induced macular degeneration, Dr. Lane said, commonly known as macular pucker. Extreme exposure to sunshine can induce this condition as well. “The effect of the sun tends to liquefy the vitreous,” he said. “In people who are very nearsighted, as the eyeball expands and the vitreous that’s laid down at birth is no longer manufactured, the added-on volume becomes filled with liquid.”

If a patient exhibits a deficiency in both zinc and copper (the major antagonist of zinc), he said, prescribing supplements at different times of the day usually solves the problem. “With a time separation, we can get both in quite well,” he said.

In comparison to oral medications, said Dr. Richer, vitamins generally tend to be safe. “When you start talking about systemic side effects, you’re really talking about drugs, and not nutrients,” he said. “On the whole, vitamins are fairly safe. There are only a few exceptions that you have to watch out for.”

Preventing mercury cataracts

Vitamin C, the same vitamin that can inhibit absorption of copper and chromium if taken in too large a dose, has been shown to be deficient in patients who develop cataracts, said Dr. Lane. Data have shown that people lacking in vitamin C, riboflavin, vitamin B-2 and antioxidants are often prone to the development of cataracts. But once again, he cautioned, the key to supplementation is balance. “Too much vitamin B-2 actually causes discoloration of the crystalline lens and can promote some types of cataract,” he said. “You really should not encourage massive supplementation of vitamin B-2 in proportion to other vitamins. We know that all of the B-complex vitamins are very important.”

Vitamin C also helps to pull out the toxic mercury that results from the consumption of large fish, such as tuna, swordfish and shark. Dr. Lane said that his 1982 study found that mercury, which would accumulate in the crystalline lens, resulted in the depression of enzymes such as superoxide dismutase and glutathione peroxidase. The latter is the primary enzyme that helps prevent mercury cataracts from forming. “Organic mercury is the worst offender because it’s able to penetrate membranes and get into organic tissues,” he said.

Early stages often overlooked

In the early stages, this form of cataract manifests as very small bubbles (vacuoles) that are easily overlooked, Dr. Lane warned. The small vacuoles of the anterior subcapsular surface of the crystalline lens often have minimal effect on vision during this period. “These cells that are generated as new cells, in the front of the eye, will migrate to the back of the lens,” Dr. Lane said. “It becomes a greater problem when they migrate to the back and we see a posterior subcapsular cataract developing. At first, it’s just an accumulation of what looks like a lot of little bubbles that start aggregating, and as they aggregate, they form clumps. Then, 5 years after this earlier episode, we find nuclear cataracts developing.”

By the time a nuclear cataract develops, he said, the effect on a patient’s vision may not be quite what is expected. Instead of deteriorating vision, the patient first may experience the ability to read without glasses. “It’s second sight,” he said. “Suddenly people who are farsighted don’t need their hyperopic glasses anymore. That’s an early change as the lens starts swelling, then starts clouding.”

There are other reasons in addition to mercury poisoning to explain a clouding of the crystalline lens, he said, such as lifestyle habits or other health problems that can affect the eye. Excessive alcohol drinking, cigarette and cigar smoking and, especially, too much sun exposure can result in the formation of cataracts.

Fighting cataracts with food

Loading up on vegetables is just as important to help halt cataract development or prevent them from forming, Dr. Lane urged. Again, green leafy vegetables are spotlighted as an effective way for patients to get the necessary amount of vitamin C, beta carotene (which can be converted to vitamin A) and vitamin B-complex for whole-body benefits. “That should be the first priority,” he said. “Patients should eat them as if they’re going out of style, and they’ve got to eat them now. Start out eating them raw first, as in a salad, which is a good way to get vitamins. Then, we can cook them. When we are finished, they will be doing a great job in reversing a recently formed cataract. Cataracts that have occurred within the past year are much more reversible.”

Foods that can cause a high glycemic index, such as those containing refined sugar, should be avoided, he said. “Glycemic index is a factor in producing metabolic cataracts,” he said. “We know that people who are diabetics get cataracts more easily than others. So the bottom line is, people who are diabetic should be careful about foods that have too high a glycemic index.”

Entire body benefits

While the evidence for dietary changes and supplementation may be more compelling for AMD than cataracts, they can only benefit the patient in either situation, said Dr. Quinn. Particularly in the case of AMD, this option provides the patient with more hope. “Until we focused on the vitamin angle, these patients had no options,” he said.

Dr. Lane stressed that, while lutein is invaluable to retinal health, all carotenoids are just as important to maintain overall health and should not be neglected. “Lutein is very important in the retina, but we must appreciate that we’re dealing with a whole symphony,” he said.

For Your Information:

Stuart P. Richer, OD, PhD, FAAO, is chief of optometry at the North Chicago VA Medical Center Eye Clinic. He may be reached at DVA Medical Center, North Chicago, IL 60064-3095; (847) 688-1900, ext. 5406; fax: (847) 578-6924; e-mail: stuart.richer@med.va.gov. Dr. Richer has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Benjamin C. Lane, OD, CNS, FAAAS, FAAO, FACN, FCOVD, is the director of Nutritional Optometry Associates. He can be contacted at 16 N. Beverwyck Rd., Lake Hiawatha, NJ 07034-0131; (973) 335-0111; fax: (973) 335-2882; e-mail: NutriOptom@aol.com. Dr. Lane has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Christopher Quinn, OD, is in private practice at Omni Eye Services. He can be reached at 485 Rte. 1, Ste. A, Iselin, NJ 08830; (732) 750-0400; fax: (732) 750-1507; e-mail: cqod@home.com. Dr. Quinn did not disclose if he has a direct financial interest in the products mentioned in this article or if he is a paid consultant for any companies mentioned.