Guest guest Posted October 11, 2004 Report Share Posted October 11, 2004 " HSI - Jenny Thompson " <HSIResearch Oyster Goggles Mon, 11 Oct 2004 08:41:46 -0400 Oyster Goggles Health Sciences Institute e-Alert October 11, 2004 ************************************************************** Dear Reader, In previous e-Alerts I've told you about the benefits of adding zinc to your daily supplement regimen. Now a new study shows yet another way that zinc can help maintain good eyesight by offering protection against a debilitating eye disease. --------------------------- Promoting the protein --------------------------- The retina of the eye receives and processes light with photoreceptor cells. If these cells degenerate, vision is progressively lost. And that's exactly what happens with an inherited condition known as retinitis pigmentosa (RP). Researchers have identified more than 100 genes that can carry mutations associated with RP. A recent laboratory study from Dartmouth Medical School examined the role that zinc deficiency plays in night blindness and retinal dysfunction caused by gene mutation. As reported in the Journal of Biological Chemistry, specific attention was given to rhodopsin, a protein in the eye that requires adequate levels of zinc to function normally. The Dartmouth researchers identified a " zinc coordination site " within rhodopsin. They found that if this site is corrupted by gene mutations, zinc is prevented from binding to the protein, setting the stage for development of RP. Dr. John Hwa, one of the authors of the study, told Reuters Health that his study shows how rhodopsin functions abnormally when the coordination site is deprived of zinc, either by gene mutation or zinc deficiency. When this occurs, the retina degenerates, followed by poor night vision, reduction in peripheral vision and eventually blindness. Dr. Hwa notes that further studies will be needed to determine exactly how much zinc intake is needed to help prevent the rhodopsin malfunction that leads to RP. --------------------------- The eyes have it --------------------------- Although we may not know exactly how much zinc might offset the danger of retinitis pigmentosa, we do know that 80 mg of zinc daily has been shown to help improve vision generally, while also reducing the risk of age-related macular degeneration (AMD). In the e-Alert " Study Proves Supplements can Save your Sight " (10/18/01), I told you about a clinical trial called the Age-Related Eye Disease Study (AREDS) sponsored by the National Eye Institute. For more than eight years, researchers tracked nearly 3,600 participants between the ages of 55 and 80 to examine the effects that antioxidant supplements have on AMD. The results: High levels of zinc and antioxidants were shown to significantly reduce the risk of AMD, and the same supplements (if administered in the early stages of AMD) may also significantly inhibit the total amount of vision loss that would normally be caused by advanced AMD. The AREDS team recommended that anyone at high risk of developing AMD should consider taking daily supplements in the amounts used in the study: * Zinc (as zinc oxide) - 80 mg * Vitamin C - 500 mg * Vitamin E - 400 IU * Beta-carotene - 15 mg For those who do include zinc in their daily supplement intake, it's also a good idea to add a little copper as well. In the e-Alert " Aim High " (5/7/03), HSI Panelist Allan Spreen, M.D., noted that zinc can create a copper deficiency, and vice versa. And Jonathan V. Wright, M.D., agrees, stating that, " Zinc supplements should usually be offset by a small amount of copper, 1-2 mg daily. " Fortunately, many multivitamins already provide a low dose of copper, taking care of the necessary zinc/copper ratio. --------------------------- The oyster bar is open --------------------------- As the Dartmouth, AREDS and other studies have shown, zinc is an indispensable nutrient for vision health. But in addition to insuring good eyesight, zinc has also been shown to provide several other key benefits, such as enhancement of the immune system, assistance in the repair of damaged tissues, and inhibition of the abnormal clotting that contributes to cardiovascular disease. Zinc is also one of the key nutrients needed for DNA reproduction and repair. To add more zinc to your diet, all you need to do is increase your intake of the food that has the highest zinc content: oysters. But if oysters aren't your cup of tea, then red meat, poultry, beans, nuts, whole grains and dairy products also provide zinc. Zinc is generally best absorbed when the diet is rich in animal protein. Subjects who participate in placebo-controlled studies know that they have a chance of taking a pill that contains little or no active ingredients. Nothing wrong with that, of course. But when doctors prescribe placebos instead of drugs without their patients' knowledge, enough ethical questions are raised to make a malpractice attorney go weak in the knees. In a recent survey of nearly 90 doctors and nurses in Israel, an astonishing 60 percent admitted that they had given placebos to patients. According to a New York Times report on the survey, placebos were mostly prescribed for patients who firmly insisted on receiving medication when none was needed. But more than ten percent of those surveyed said they just wanted to get the patient to stop complaining. Take two of these and DON'T call me in the morning! One odd detail stood out in this report. Most of the caregivers told their patients that they were receiving real medicine. But four percent told their patients that they'd be receiving a placebo. I guess that would mean that about four percent of the doctors and nurses in this survey are not clear on how a placebo is supposed to work. I'm no doctor, but it seems to me that if you tell the patient the truth, the chance of experiencing a placebo effect plummets to about zero. A similar survey, conducted last year in Denmark, also showed that quite a few doctors had prescribed placebos. But here in the U.S.? One California doctor told the Times that it's " unheard of. " Which, technically, would mean that it may happen every day, but you just don't hear about it. But you never know. So here are four tip-offs that your doctor has prescribed a placebo: * An entire month's supply of pills costs about the same as a large bag of M & M's * The information flyer that comes with the " medication " doesn't list any side effects * The recommended dosage is referred to as a " serving " * The bottle doesn't have a child-proof cap Maybe if doctors would just start prescribing placebos instead of real drugs, we might have the solution to adverse side effects and skyrocketing drug prices. To Your Good Health, Jenny Thompson Health Sciences Institute ************************************************************** Sources: " Critical Role of Transmembrane Segment Zinc Binding in the Structure and Function of Rhodopsin " Journal of Biological Chemistry, Vol. 279, No. 34, 8/20/04, ncbi.nlm.nih.gov " Zinc Shortage May Underlie Serious Vision Problem " Megan Rauscher, Reuters Health, 9/9/04, reutershealth.com " The Effect of Antioxidant Vitamins and Zinc on Age-Related Macular Degeneration and Cataract " From the AREDS, National Eye Institute, October, 2002, nei.nih.gov " This Pill Will Make You Feel Better, but We're Not Sure Why " Denise Grady, The New York Times, 9/28/04, nytimes.com Copyright ©1997-2004 by www.hsibaltimore.com, L.L.C. The e-Alert may not be posted on commercial sites without written permission. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.