Dr. Grossman’s Blog

In the first study, Jennifer S.L. Tan, MBBS, BE at the University of Sydney, Australia and her colleagues evaluated data from 2,454 participants in the Blue Mountains Eye Study of men and women aged 49 and older. Those who consumed one serving of fish per week were shown to have a 31 percent lower adjusted risk of developing early AMD compared with those who consumed less.

In the second article, Elaine W. T. Chong, MD, PhD, of the Centre for Eye Research Australia and her associates evaluated data from 6,734 men and women aged 58 to 69 who participated in the Melbourne Collaborative Cohort Study. Dietary questionnaires completed between 1990 and 1994 were analyzed for the intake of various foods and individual fatty acids. Follow up examinations conducted between 2003 and 2006 detected 2,872 cases of early age-related macular degeneration and 88 cases of late disease.

A high intake of trans-unsaturated fats was associated with a significant increase in late macular degeneration, with those whose intake was categorized as among the top 25 percent of participants having a 76 percent greater risk than those whose intake was among the lowest fourth.

Olive oil emerged as protective against late disease. When those who reported consuming at least 100 milliliters per week olive oil were compared with those who consumed less than 1 milliliter per week, they were found to have a 52 percent lower risk of late AMD.

For early AMD, those whose omega-3 fatty acid intake was among the top 25 percent had a 15 percent lower risk compared with those whose intake was among the lowest quarter.

For more information on nutrition and macular degeneration and related research studies, see NaturalEyeCare’s Section on Macular Degeneration.

A team of scientists and surgeons from the Institute of Ophthalmology at University College London and the Moorfields Eye Hospital in London has developed a stem cell therapy to treat age-related macular degeneration (AMD), the most common cause of vision loss in the elderly.
“Under the new treatment, embryonic stem cells are transformed into replicas of the missing cells,” writes The Times of London. “They are then placed on an artificial membrane which is inserted in the back of the retina.”

Pharmaceutical giant Pfizer announced this week that it will fund the development of the therapy; UCL professor Pete Coffey, who led the research team, predicts the therapy will be available as part of a simple, one-hour procedure within six or seven years.The researchers are applying for approval to conduct a clinical trial on humans; it would be just the second-ever trial conducted on humans using embryonic stem cells. Laboratory trials completed by the British team have demonstrated that stem cells can prevent blindness in rats with a similar disease to AMD. They have also successfully tested elements of the technology in pigs.

For natural approaches to help prevent the onset of macular degeneration as well as help preserve vision for those with macular degeneration, visit the Natural Eye Care web site

In people with the highest level of consumption of lutein and xeaxanthin (from leafy greens, eggs, red and yellow peppers), risk of Macular Degeneration (AMD) was 35% of the risk in people who ate less greens. Zinc was also protective. This in a study by J.S. Tan, et al. in Opthalmology, February 2008.

For more related research studies, see the “Research” section at http://www.naturaleyecare.com”>Natural Eye Care for Macular Degeneration</a>

A new European study suggests that the combination of low levels of antioxidants and blue light exposure from the sun is associated with certain forms of age-related macular degeneration (AMD).

The EUREYE study, led by Astrid Fletcher, Professor of Epidemiology of Ageing at the London School of Hygiene & Tropical Medicine, is the first to report an adverse association between sunlight exposure and AMD in people with low levels of antioxidants.

It is known that the eye is vulnerable to the damaging effects of sunlight. Ultraviolet radiation is absorbed by the lens, but visible or “blue” light penetrates to the retina, enabling us to see. Protection against the harmful effects of blue light is provided by antioxidant enzymes—including vitamins C and E, the carotenoids (lutein and zeaxanthin) and zinc.

Researchers measured levels of these nutrients in the blood of 4,753 older adults (average age 73.2) who were part of the European Eye Study. Participants were interviewed about their lifetime sunlight exposure and had photographs taken of their retinas to detect AMD.

Participants with the lowest concentrations of antioxidants in the blood were found to be most at risk of AMD due to blue light exposure. In fact, participants with the combination of blue light exposure and low levels of zeaxanthin, alpha tocopherol and Vitamin C were nearly four times more likely to develop AMD. Researchers also noted that blue light exposure in middle age might be more damaging than at younger ages.

Professor Fletcher comments: ‘In the absence of cost-effective screening methods to identify people in the population with early AMD, we suggest that recommendations on protecting the eyes, ensuring that diets contain the right nutrients and antioxidants, are targeted at the general population, and especially middle-aged people’.

Study authors don’t advise people to stay out of the sun altogether — sunlight is important for its role in vitamin D synthesis. However, they do recommend avoiding exposing eyes to too much sunlight by wearing a wide-brimmed hat and sunglasses when outdoors.

In addition, study authors advise consumption of key antioxidants, which can be accomplished by consuming recommended dietary intake levels of vitamin C and zinc and increasing consumption of carotenoid-rich fruits and vegetables.

Learn more about macular degeneration

Read more about antioxidants and nutrient food sources for good eye health

SOURCE: Fletcher AE et al. Sunlight exposure, antioxidants, and age-related macular degeneration. Archives Ophthalmology 2008; 126:1396-1403.

U.S. researchers found that antioxidants disrupt a link between two processes in the retina that, in combination, contribute to macular degeneration. Antioxidants also extend the lifetime of irreplaceable photoreceptors and other retinal cells.

The “destructive synergy” that causes macular degeneration occurs when a buildup of a compound called A2E disrupts energy production in mitochondria, the “power plants” in cells, the researchers said. The lack of energy interferes with daily cleaning and maintenance of photoreceptors and another type of retinal cell. This leads to more buildup of A2E and a continuing cycle that results in the destruction of the vital visual cells that can’t be replaced.

The study was published online in the Journal of Biological Chemistry.

For more information and specific research studies by eye condition on nutrition and vision, go to <a href=”http://www.naturaleyecare.com”>Natural Eye Care for Macular Degeneration</a>

Studies show that people with Stargardt’s Disease genetically do not make an enzyme to get rid of the waste products from metabolized Vitamin A analogs and the build up of these waste products leads to the death of retinal cells, so supplementing with Vitamin A should be avoided. Also, certain foods should be restricted that are high in Vitamin A. Fruits to be restricted include: tomatoes, cantaloupes, watermelon, peaches, kiwi, oranges, and blackberries. Vegetables high in Vitamin A include: carrots. kale, spinach and sweet potatoes.

For more information and related studies, go to www.naturaleyecare.com .

Lutein and zeaxanthin have been well researched as being essential nutrients in both helping to prevent the onset of macular degeneration as well as helping protect vision for those with macular degeneration. People with macular degeneration have been shown to have reduced macular pigment optical density (MPOD).

Meso-zeaxanthin is the third major carotenoid found in macular pigment (along with lutein and zeaxanthin).

A new study showed that supplementation of gelcaps containing mostly mesozeaxanthin (along with some lutein and zeaxanthin) resulted in increased blood serum levels of all three carotenoids during the 120 day study supplementation period, and was effective in increasing macular pigment optical density (MPOD).

Ref: Florida International University (Nutr Metab. 2007;4:12) (DOI:10.1186/1743-7075-4-12).

For more information on related studies, go to www.naturaleyecare.com

Researchers using data from the Third National Health and Nutrition Examination Survey (1988 through 1994) have found evidence that consuming vitamin D may help ward off age-related macular degeneration (AMD). 

In this study, 7752 individuals (including 11% with AMD) were given retinal photographs, dietary intake questionnaires, and blood tests to calculate blood vitamin D (25-hydroxyvitamin D) levels.  Based on these vitamin D blood levels, participants were divided into 5 groups.   Participants in the group with the highest vitamin D levels showed 40% lower risk of developing early AMD than those in the lowest group. 

Analysis was also conducted to evaluate associations with important food and supplemental sources of vitamin D. 

• People who drank milk daily decreased their risk of developing AMD, as did those who took supplemental vitamin D consistently but didn’t drink milk daily. 
• Fish consumption was also linked with a lower risk of advanced AMD.

What are good sources of vitamin D?  Consider fish — it’s naturally rich in vitamin D.  Milk and breakfast cereals are generally fortified with vitamin D as well. 

Read more about AMD

Learn tips for taking vitamins and maintaining good digestion

SOURCE:  “Association between vitamin D and age-related macular degeneration in the Third National Health and Nutrition Examination Survey”, Parekh N, et al. Arch of Ophthalmol 125:661-69, 2007.

FRIDAY, Aug. 29 (HealthDay News) — Eating plenty of antioxidant-rich food such as blueberries, artichokes and pecans may help protect against macular degeneration, the leading cause of age-related blindness in the United States and other developed countries.

U.S. researchers found that antioxidants disrupt a link between two processes in the retina that, in combination, contribute to macular degeneration. Antioxidants also extend the lifetime of irreplaceable photoreceptors and other retinal cells.

The “destructive synergy” that causes macular degeneration occurs when a buildup of a compound called A2E disrupts energy production in mitochondria, the “power plants” in cells, the researchers said. The lack of energy interferes with daily cleaning and maintenance of photoreceptors and another type of retinal cell. This leads to more buildup of A2E and a continuing cycle that results in the destruction of the vital visual cells that can’t be replaced.

Experiments using visual cells from humans, rats and cows showed that antioxidants could completely counter the damage caused by this process, said the researchers from Brigham Young University and Weill Medical College of Cornell University.

“The implication is that people at risk of macular degeneration could help prevent the disease by consuming antioxidants,” study author Heidi Vollmer-Snarr, a Brigham Young chemist, said in a university news release.

The study was published online in the Journal of Biological Chemistry.

“This work by Dr. Vollmer-Snarr and colleagues ties these two damaging processes together and demonstrates the harm they cause in combination is much more than would be expected,” Dr. Paul Bernstein, of the University of Utah’s Moran Eye Center, said in the news release. “This new knowledge,” added Bernstein, who wasn’t involved in the study, “suggests the possibility of interventions which could prove to be powerful ways to prevent or delay age-related macular degeneration.”

For more related studies, go to the “Research” section as www.naturaleyecare.com

A combination of exposure to blue light from sunlight and inadequate levels of antioxidants in the blood contribute to the development of some forms of the eye disease age-related macular degeneration (AMD), say researchers.

Astrid E. Fletcher, PhD, of the London School of Hygiene & Tropical Medicine, and colleagues measured levels of vitamin C and E, the carotenoids lutein and zeaxanthin, and zinc, in the blood of 4,753 seniors with an average age of 73.2 years. The participants were also questioned about sun exposure, and had photographs taken of their retinas.

Results showed that of the 4,400 participants with complete data, 2% had neovascular AMD, an advanced form of the disease, and 50% had early-stage AMD. Overall, there was no link between blue light exposure and neovascular AMD or early-stage AMD. However, participants with a history of blue light exposure and low blood levels of zeaxanthin, vitamin E, and vitamin C were found to be 3.7-times more likely to develop neovascular AMD.

The researchers conclude: Our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

Posted in Nutrition, Sensory on Thu October 16, 2008

Fletcher AE, Bentham GC, Agnew M.Sunlight Exposure, Antioxidants, and Age-Related Macular Degeneration. Arch Ophthalmol. 2008;126:1396-1403.

For more related studies, see the “Research” section at www.naturaleyecare.com