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Resources: Nutrition & Vision: An Eye on Prevention: Nutrients

 

Nutrients, not just screening, are key to preserving vision health.

By Joseph King

 

A Research To Prevent Blindness Survey found that blindness ranked third (after cancer and heart disease) as people's major fear. According to the Macular Degeneration Foundation (MDF), a recent poll showed Americans dread blindness more than any other disability.

 

Because the two leading causes of blindness—glaucoma and macular degeneration—affect predominantly the elderly, preventative measures among an aging baby-boomer population are being promoted as a solution to long-term eye health, according to industry sources.

 

However, Neil Levin, nutrition education manager for Bloomingdale, IL-based NOW Foods, said prevention is more than just examinations.

 

“Prevention gets a lot of lip service, but in medical terms this means early screenings for disease,” Levin said. “Real prevention is being healthy and getting a wide range of antioxidant nutrients, including the all-important plant pigments (mostly from whole fruits), which bind free iron to prevent oxidative damage and inflammation.”

 

NOW Foods offers Clinical Strength Eye Support, formulated to provide eye support by delivering nutrients necessary to protect against damaging oxidation.

 

Macular degeneration is the leading cause of blindness among people 55 and older, affecting more than 12 million Americans, according to the Macular Degeneration Foundation (MDF).

 

Macular degeneration is caused by the deterioration of the central portion of the retina (known as the macula), the inside back layer of the eye that records the images we see and sends them to the brain. The macula is responsible for focusing central vision in the eye, and it controls our ability to read, drive a car, recognize faces or colors, and see objects in fine detail.

 

There are two types of macular degeneration—dry and wet. Ninety percent of all people with macular degeneration have the dry type. However, wet macular degeneration accounts for 90 percent of all blindness from the disease, according to the National Eye Institute.

 

Glaucoma is the second leading cause of blindness in the world, according to the World Health Organization. Glaucoma is an eye disease in which the normal fluid pressure inside the eyes slowly rises, leading to vision loss and blindness.

 

Approximately 120,000 are blind from glaucoma, accounting for 9 to 12 percent of all cases of blindness in the U.S., according to the National Eye Health Program/National Institutes of Health.

 

Adult glaucoma falls into two categories—open angle glaucoma and closed angle glaucoma. Prevent Blindness America estimates that more than three million Americans suffer from glaucoma but only half of those know they have it.

 

Medication and surgery may possibly halt further vision loss due to glaucoma but currently there is no cure for glaucoma, and vision lost due to glaucoma cannot be restored.

 

While everyone is at risk for glaucoma, senior citizens are at a higher risk for glaucoma but babies can be born with it (approximately 1 out of every 10,000 babies born in the U.S., according to the Glaucoma Research Foundation).

 

A healthy diet high in a wide range of antioxidant nutrients is an important factor in maintaining good eye health. Smoking, obesity, inadequate consumption of fruits and vegetables, sun exposure without UV and “blue-blocker” sunglasses, chemical exposure, and cardiovascular problems are the most detrimental factors to eye health. Circulatory problems, along with high blood sugar, are associated with increased risk of diabetic blindness.

 

Antioxidants and Vision Health

 

Research has shown that well-known antioxidants, such as vitamins C and E and beta-carotene, play a vital role in preserving eye health.

 

A study published in the Dec. 28, 2005 issue of the Journal of the American Medical Association (JAMA) demonstrated that a diet with a high intake of beta carotene, vitamins C and E, and zinc is associated with a substantially reduced risk of age-related macular degeneration (AMD) in elderly persons. However, the authors downplayed the role of supplementation.

 

“This study suggests that the risk of AMD can be modified by diet; in particular, by dietary vitamin E and zinc,” the authors wrote in JAMA. “A higher intake of vitamin E can be achieved by consumption of whole grains, vegetable oil, eggs, and nuts. High concentrations of zinc can be found in meat, poultry, fish, whole grains, and dairy products. Carrots, kale, and spinach are the main suppliers of beta carotene, while vitamin C is found in citrus fruits and juices, green peppers, broccoli, and potatoes.

 

“Based on this study, foods high in these nutrients appear to be more important than nutritional supplements. Until more definitive data are available, this information may be useful to persons with signs of early AMD or to those with a strong family history of AMD. Although in need of confirmation, our observational data suggest that a high intake of specific antioxidants from a regular diet may delay the development of AMD,” the authors concluded.

 

Research has also demonstrated the role two carotenoids play in eye health—zeaxanthin and lutein. Of all the carotenoids in the diet, the human retina accumulates only these two. Zeaxanthin protects the retina of the eye from the damaging effects of light, while lutein plays a role in reducing the risk of AMD.

 

“The plant pigments are the key to eye health,” said Levin. “These antioxidant powerhouses protect and support various eye tissues.

 

“These include the yellow pigments (lutein and zeaxanthin from marigold flowers, yellow squash), orange pigments (carotenoids from sweet potatoes, carrots and algae) and blue pigments (anthocyanidins from blueberries, bilberry. and algae),” he said. “The other antioxidant nutrients, particularly vitamins A, C, and E, plus selenium (ACES), enhance the protective effects.”

 

In 2001, the National Eye Institute sponsored the first of two clinical trials called the Age-Related Eye Disease Study (AREDS). Results from the study showed that high levels of antioxidants and zinc significantly reduce the risk of advanced age-related macular degeneration (AMD) and its associated vision loss. However, study results showed these same nutrients had no significant effect on the development or progression of cataract.

 

“Lutein, vitamin C, and vitamin E are by far the superstars thanks partially to the first [AREDS],” said Manuel Pavon, general manager of West Chicago, IL-based Chrysantis, manufacturer of EZ Eyes. “Bilberry is growing at a healthy pace, while zeaxanthin is the new star rising.”

 

Pavon noted that a couple of studies have shown that high doses of lutein seem to stop, and maybe potentially reverse, AMD. However, Pavon admits more studies are needed to confirm that hypothesis. “At any event, under DSHEA [the Dietary Supplement Health and Education Act] we are prevented from making any claim in that sense,” he said. “Dietary supplements are first and foremost about prevention.”

 

Pavon added that lutein is not the beginning and the end of the category. “It has benefited from aggressive marketing over the last decade, but there are dozens of vitamin and nutrient combinations available to the public and no one can say today what is the best product,” Pavon said. “With the aging population's desire to stay active and independent, preserving eye health is viewed as extremely important.”

 

Mechanisms of Action

 

There is an important research effort to understand the overall action mechanisms of antioxidants in general and carotenoids in particular, according to Pavon.

 

“I see two main research themes,” he said. “One that is looking into the synergistic effects associated with the intake of a particular combination of antioxidants, and the other that is looking at the carotenoid metabolites, which some people believe could be even more effective than the original carotenoid.

 

“Other studies are trying to confirm anecdotal evidence about zeaxanthin and lutein influence over vision acuity and color perception and the results are still inconclusive,” Pavon said. “There is also a constant stream of articles derived from the first AREDS study, and we will soon see the AREDS II study that is looking at lutein, zeaxanthin, and DHA.”

 

Patients in the first AREDS research will be involved in a continuing study, with some important changes, according to the Macular Degeneration Partnership.

 

Two of the major concerns in the first AREDS were the high level of zinc in the vitamin and the lack of lutein/zeaxanthin in the vitamin itself. AREDS II will address these issues by offering some of the original patients in the study an AREDS vitamin with a lower level of zinc. Smokers in the group will receive an AREDS vitamin without beta-carotene, but with lutein. The exact formulae are still to be determined, and it will take 10 years for the full data to be known.

 

Roger Kendall, vice president of research and development for FoodScience of Vermont in Essex Junction, VT, noted several other nutrients that have shown promise in helping promote long-term eye health. Alpha lipoic acid is touted as maintaining good capillary health and flow into eyes and the prevention of cataracts, and quercetin has been shown to inhibit the buildup of a blood sugar that could otherwise lead to cataract formation in the lens of the eye.

 

“The evidence for nutrients aiding eye health and function is increasing monthly,” Levin said. “The fatty acid DHA may slow the rate of vision loss in people with an eye disease known as retinitis pigmentosa, as reported in the American Journal of Ophthalmology.”

 

Reversing the Damage

 

The natural products industry has always touted its products as beneficial for the prevention of health maladies. However, a study in the April 2004 issue of Optometry: Journal of the American Optometric Association reported that taking the right combination of lutein, vitamins, and antioxidants may counter or reverse the effects of AMD and lead to healthier and more productive lives for patients.

 

“When it comes to the degeneration of eyes these same nutrients are being found to help reverse the early stages of macular degeneration and the slowing of cataract formation,” said Kendall.

 

FoodScience offers Eye-Sentials, described as an advanced nutritional supplement designed to maintain ocular health, as well as a number of different individual antioxidants.

 

“Since many age-related eye problems are really oxidation-related—such as poor night vision, cataract, and macular degeneration—younger people with these problems are probably deficient in antioxidant nutrients,” said Levin. “These problems typically occur in people in their fifties, or later. Because poor diet or a loss of nutrients from other demands on the body (oxidative stress, immune stress, detoxification, etc.) can trigger early onset of these conditions, it is often wise to take a variety of antioxidant nutrients.

 

“These nutrients include vitamin A, beta carotene, vitamin E (up to eight natural forms), vitamin C, selenium, lutein, zeaxanthin, lycopene, and other plant pigments like bilberry,” he added.

 

Focus on Education

 

Manufacturers agree that retailers are the first line of education about eye health supplements for consumers, and providing retailers with education materials and information is key to helping this segment grow into a category leader.

 

“Retailers can use the information given by manufacturers which in our case includes the Health Professor flyers, e-newsletters, and technical sheets on specific products like NOW Clinical Strength Eye Support,” Levin said. “In a product segment, NOW has a technical sheet on our Website listing the references for using the nutrients in our Clinical Strength Eye Support formula.”

 

NOW also offers an e-newsletter with abstracts from recent research (all topics; not limited to eye health). “Retailers have to have some sense of how the products in a category compare beyond the marketing claims,” Levin said. “The people at NOW Foods believe that good science and quality controls, along with a well-reasoned formulation in proper proportions, are the key ingredients to create a category leader.”

 

Kendall agreed that the onus is on the manufacturers to support research into ocular health supplements at leading universities and institutions.

 

Tony Lucchesi, national sales trainer for Source Naturals (Scotts Valley, CA), said the first step for retailers is to educate consumers about the problems and issues surrounding ocular health.

 

“Retailers need to take a proactive approach to be a health resource in their community about ocular health,” Lucchesi said. “Retailers could give a presentation on eye health themselves or bring in a guest speaker, who is an expert in the field, after-hours and tie in a discount promotion on eye health supplements.”

 

Source Naturals offers Visual Eyes multi-nutrient complex with bilberry extract, lipoic acid, and lutein. It also offers a separate lutein supplement in 6- and 20-mg strengths and a zeaxanthin with lutein supplement.

 

Lucchesi said Source Naturals provides retailers with a wide range of educational assistance. “We educate retailers so they can relay the information to their customers,” he said. “We need to educate retailers on which consumer fits which product.”

 

The educational and informational resources for retailers to tap into are many, according to Pavon. “Brochures, weekly or monthly letters (printed or electronic), a well educated staff in the stores that answer the public's questions, and TV programs aimed at explaining disease symptoms are some of the tools they can use,” Pavon said. “All this information is free and is widely available. Retailers who understand the importance of education attend seminars at trade shows, read the trade magazines, and utilize manufacturer Websites to stay on top of the latest findings and developments.”

 

The ARVO (Association for Research in Vision and Ophthalmology) annual conference (this year scheduled for April 30 to May 2 in Fort Lauderdale, FL), the Gordon conferences held throughout the year on a variety of subjects, and events organized by the Carotenoid Society are important venues for the scientists to present their research, according to Pavon.

 

“There are also conferences at all the important industry expositions: the NNFA show, the SupplySide expos (East and West), the Nutracon conference (Expo West), Vitafoods, to mention the most important ones,” he added. “Many manufacturers utilize these events to educate the industry on the importance of eye health products.”

 

Kendall added that reaching out to your local ophthalmologists is another way to attract attention to eye health supplements in your store. “I think acceptance of eye health supplements is increasing among ophthalmologists,” he said. “They are going to their conventions and their programs and they are getting the research and discoveries.

 

“At first they may look at eye health supplements with a bit of skepticism,” Kendall concluded. “But when they begin to read the research, they start to accept it.” VR

 

(The Above Article is a reprint from VITAMIN RETAILER, May 2006, Pages 42-47)