Dr. Grossman’s Blog

Researchers at the Department of Ophthalmology and Jules Stein Eye Institute, University of California-Los Angeles, recently studied the association between consumption of fruits and vegetables and the presence of glaucoma.

1,155 women located in multiple centers in the United States participated in this cross-sectional cohort study. Glaucoma specialists evaluated the women for glaucoma; consumption of fruits and vegetables was assessed using a food frequency questionnaire.

Among the 1,155 women studied, 95 (8.2%) were diagnosed with glaucoma. Analysis of the relationship between selected fruit and vegetable consumption and glaucoma showed:

• Glaucoma risk was decreased 69 percent in women who consumed at least one serving per month of green collards and kale compared with those who consumed fewer than one serving per month.
•  Glaucoma risk was decreased 64 percent in women who consumed more than two servings per week of carrots compared with those who consumed fewer than one serving per week.
• Glaucoma risk was decreased 47 percent in women who consumed at least one serving per week of canned or dried peaches compared with those who consumed fewer than one serving per month.

Although researchers note that more studies are needed to investigate the relationship between nutrition and glaucoma, research to date does indicate that a higher intake of certain fruits and vegetables may be associated with a decreased risk of glaucoma.

Learn more about glaucoma

Read other studies about nutrition and glaucoma

SOURCE: “Glaucoma risk and the consumption of fruits and vegetables among older women in the study of osteoporotic fractures”, Coleman, et al, Am J Ophthalmol. 2008 Jun;145(6):1081-9.

A new study indicates that the carotenoids lutein and zeaxanthin may help improve vision under glare conditions such as bright sunlight or the beams of car headlights.

Scientists at the Vision Science Laboratory at the University of Georgia recently studied the relationship of lutein and zeaxanthin on macular pigment (MP), glare disability, and photostress recovery.

The macula helps filter damaging light rays. When the concentration of lutein and zeaxanthin in the macula is higher, the higher density of macular pigment enables the macula to absorb the light rays more efficiently.

Researchers studied forty healthy subjects (average age of 23.9) for six months, giving assessments at baseline, 1, 2, 4, and 6 months. Subjects were given 12mg daily of lutein and zeaxanthin supplements.

After 6 months, the lutein and zeaxanthin supplementation was shown to significantly reduce the negative effects of glare for both the visual performance tasks assessed for most of the subjects.

Read other studies about lutein and zeaxanthin, including their role in preventing macular degeneration and cataracts.

Learn more about natural leutein and zeaxanthin supplements

SOURCE: “Macular pigment and visual performance under glare conditions”, Stringham and Hammond, Optom Vis Sci., 2008 Feb;85(2):82-8

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

Can something as easy as taking a daily multi-vitamin help prevent cataracts? Researchers believe it can!

An analysis of Age-Related Eye Disease Study (AREDS) data has found that consistent use of a multi-vitamin and mineral supplement may delay the progression of age-related lens opacities.  Lens opacities in the form of cataracts are the leading cause of blindness around the world today.

Of the 4596 participants enrolled in the AREDS cataract trial, approximately two-thirds elected to take a multi-vitamin supplement containing RDA-recommended levels of vitamins and minerals.

Subjects were assessed for development or progression of lens opacities via lens photographs at baseline and at annual visits beginning at year 2.  Statistics were collected on changes in amounts of nuclear, cortical, or posterior subcapsular opacity, or the performance of cataract surgery.

Researchers found the risk of development of or progression to any cataract was reduced by 16% in regular multi-vitamin takers. For nuclear cataract, a 25% risk reduction was observed in the multi-supplement users.

Read more about cataracts, including recommended vitamins and supplements

SOURCE:  “Centrum Use and Progression of Age-Related Cataract in AREDS”, AREDS Research Group, Ophthalmol 113:1264-0, 2006.

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.

The findings provide hope for treating blindness caused by optic-nerve damage, but
also look promising for spurring similar regeneration in the spinal cord and brain.
Researchers said Monday a newly discovered growth factor could hold the key to regenerating damaged optic nerves — and more. The research team at Children’s Hospital in Boston say they have found a naturally occurring, previously unrecognized growth factor that stimulates regeneration in injured optic nerves.
The findings provide hope for treating blindness caused by optic-nerve damage, but
also look promising for spurring similar regeneration in the spinal cord and brain,
they said.

The growth factor is called oncomodulin and when it was added to retinal nerve cells
in the lab, with known growth-promoting factors already present, the growth of axons
– or cells in the optic nerves — nearly doubled.

No other growth factor was as potent, the researchers said.

More Nerve Regeneration

In live rats with optic-nerve injury, oncomodulin released from tiny sustained-release
capsules increased nerve regeneration five- to seven-fold when given along with
a drug that helps cells respond to oncomodulin, the team said.

Oncomodulin also appears to switch on a variety of genes associated with axon growth,
the researchers said.

“Out of the blue, we found a molecule that causes more nerve regeneration than
anything else ever studied,” said one of the study investigators. We expect
this to spur further research into what else oncomodulin is doing in the nervous
system and elsewhere.

The data are published in the May 14 online edition of Nature Neuroscience.

For more related research, go to www.naturaleyecare.com (see “Research” section).

Researchers with the Hordaland Health Study reviewed the relationship between consumption of different amounts of fish (and fish products) and cognitive performance.

In this study, 2031 subjects in Norway aged 70 to 74 underwent a battery of six cognitive tests and completed food-frequency questionnaires that identified both the quantity and the type of fish consumed in their diet. Researchers then studied the associations between cognitive performance and the main types of consumed seafood, i.e., fatty fish, lean fish, processed fish, fish sandwich, and fish or cod liver oil.

They found that fish eaters had significantly better results on all cognitive tests than did the non-consumers, even after adjustment for several non-nutritional factors with a proven association with cognition (e.g., education levels).

The protective effect of eating fish and fish products extended to almost all of the tested cognitive abilities. In addition, the associations between fish and fish product intake and cognition were dose-dependent: those who ate greater amounts of fish showed better test results.

The researchers also observed that the results depend on the type of fish consumed: the effect was more pronounced for non-processed lean fish and fatty fish.

Read other studies that link fish consumption to improved eye health

Learn more about natural fish oil products

SOURCE: “Cognitive performance among the elderly and dietary fish intake: the Hordaland Health Study”, Nurk, et. al., Am J Clin Nutr; 86:1470-1478 (November 2007).

Researchers studied food and vitamin/mineral supplement consumption of adults in the United States in an effort to measure whether older adults were consuming enough nutrients.

In this study, 4,384 adults aged 51 years and older were evaluated.  1,777 reported taking supplements daily, 428 took them infrequently, and 2179 did not take daily supplements.  Nutrient intake distributions were estimated using the Iowa State University Method.

The results? 

Overall, less than 50% of adults evaluated met the Estimated Average Requirement (EAR) for folate, vitamin E, and magnesium from food sources alone.

Of those who were taking supplements, 80% or more met the EAR for vitamins A, B-6, B-12, C, and E; folate; iron; and zinc, but not magnesium.  However, it was noted that some supplement users, particularly men, exceeded Tolerable Upper Intake Levels for iron and zinc and a small percentage of women exceeded the Tolerable Upper Intake Level for vitamin A.

The researchers concluded that a large proportion of older adults do not consume sufficient amounts of many nutrients from foods alone. Supplements can help compensate for this deficiency, but only an estimated half of this population uses them daily.

Learn tips for taking vitamins and maintaining good digestion

Read about good food sources for nutrients

SOURCE: “Older adults who use vitamin/mineral supplements differ from nonuser in nutrient intake adequacy and dietary attitudes”, Sebastian, et al, Journal of the American Dietetic Assoc 107(8):1322-32, 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