Dr. Grossman’s Blog

March is the American Dietetic Association’s National Nutrition Month.

This year, the theme is “Eat Right with Color.”  That seems particularly fitting since seeing color is one of the things we value most about our eyes.  The colors of the foods we eat – we are specifically talking about fruits and vegetables here – are often indicative of the nutrients they will deliver.

Check out the ADA’s guide for what colors indicate what great health benefits.

What’s an optometrist’s favorite color?  Blue.

Bilberry (a cousin of the blueberry) is the ultimate eye food, mainly because it contains carotenoids, which are powerful antioxidants.  Getting your does of blue foods will help anyone concerned about Poor Night Vision, Glaucoma, Myopia , Macular Degeneration, Diabetic Retinopathy , Cataracts , or  Computer Eye Syndrome.

Learn about how to prevent and treat diabetes naturally at our website.

Also, get the facts about the related condition, diabetic retinopathy.

We all grew up hearing that carrots were good for our eyes.  It’s the beta-carotene in carrots that helps your vision and it can also be found in spinach, tomatoes, broccoli, and mangoes.  The body turns beta-carotene into vitamin A which in turn protects the retina and lens from free radicals, unstable molecules that can cause cell damage.  Carotenoids like lutein and zeaxanthin also contribute to eye health and those can be found in green leafy vegetables, corn, and eggs.

Learn more about foods that prevent eye diseases at NaturalEyeCare.com‘s nutrition pages.

Oral supplementation with lutein and zeaxanthin with coantioxidants may improve vision at 36 months for those at high risk for progression to late age-related macular degeneration (AMD).

In the Carotenoids and Co-Antioxidants in Age-Related Maculopathy (CARMA) study, presented at the Association for Research in Vision and Ophthalmology (ARVO) 2009 Annual Meeting, researchers examined the effects of supplementation with serum lutein and zeaxanthin plus coantioxidants (vitamins C and E and zinc) on visual function and the progression from early to late stages of AMD.

A total of 433 participants in the United Kingdom with early AMD in at least one eye, or any level of AMD in the study eye and late-stage AMD in the fellow eye, received either carotenoids plus coantioxidants or a placebo.

Study participants were examined at 12, 18, 24, 30, and 36 months. Although no statistically significant difference was seen in best corrected distance visual acuity (BC DVA) at 12 months, at the 36 month follow-up researchers did note an improved BC DVA.

Investigative team member Usha Chakravarthy, MD, PhD, from Queens University of Belfast in Northern Ireland concluded that supplementation with lutein and zeaxanthin results in better macular function in patients with early AMD. He also noted that the eyes of people who had high serum (lutein) demonstrated a less severe early AMD change over time, and suggested that supplementation may prove beneficial in preventing progression to late AMD.

Learn about self-help for macular degeneration, including recommended diet and supplements containing lutein and zeaxanthin at the Natural Eye Care website

SOURCE: ARVO 2009: Lutein, Zeaxanthin Supplements May Result in Better Macular Function in Early AMD, Chakravarthy, et al, The Association for Research in Vision and Ophthalmology (ARVO), May 4, 2009.

Lutein May Help Visual Contrast Sensitivity for Computer Users

Lutein is known to be an essential nutrient in helping prevent the onset of macular degeneration. Researchers now believe that lutein may also help protect against the detrimental effects of long-term computer display light exposure.

A study published in the British Journal of Nutrition indicates that improvements in the eye’s sensitivity to contrast on a computer screen were observed following 12 weeks of supplementation with lutein.

Scientists at the Peking University in China studied 37 healthy individuals aged 22 to 30 who had long-term computer display light exposure. Participants were randomly assigned to one of three groups: one group was given placebos, one group was given 6 milligrams of lutein daily, and one group was given 12 milligrams of lutein daily.

Levels of serum lutein and visual performance indices such as visual acuity, contrast sensitivity and glare sensitivity were measured at the beginning of the study and again at 12 weeks.

After 12 weeks researchers found an increase in blood levels of lutein in both lutein groups. The study authors noted: “Visual function in healthy subjects who received the lutein supplement improved, especially in contrast sensitivity, suggesting that a higher intake of lutein may have beneficial effects on the visual performance.”

Lutein can be found in green leafy vegetables and egg yolks. Learn about food sources for nutrients important to good eye health, including lutein.

Read other studies about the benefits of lutein for good eye health

SOURCE: “A 12-week lutein supplementation improves visual function in Chinese people with long-term computer display light exposure”, Ma, et al, British Journal of Nutrition, Published online by Cambridge University Press 19 Feb 2009 doi:10.1017/S0007114508163000.

Fresh-cut fruits is one of the fastest growing food categories in U.S. supermarkets, but what effect does processing and storage have on the nutritional value of the fruit?

Surprisingly, an international team of scientists has found that cutting and packaging fruit had almost no affect on the main antioxidants.

Their report, published in the Journal of Agricultural & Food Chemistry, shows that fresh-cut fruit retains vitamin C and other healthful antioxidants after days on the shelf.

The researchers obtained pineapples, mangoes, cantaloupes, watermelons, strawberries and kiwifruits from wholesale commercial sources in California.  The fruit was taken to a laboratory at the University of California in Davis. Half of each lot was processed as fresh-cut and half left whole.

Both lots were refrigerated under identical conditions for nine days and then tested for nutrient content. Tests showed only small losses of antioxidant compounds in the cut fruit compared to fruit left whole. Levels of some antioxidants in fresh-cut mango and watermelon actually increased due to exposure to light.

In general, researchers found that fresh-cut fruits visually spoil before any significant nutrient loss occurs. 

Learn more about antioxidants

Read other articles about the benefits of antioxidants for good eye health

SOURCE:  Quality Changes and Nutrient Retention in Fresh-Cut versus Whole Fruits during Storage, Gil et al, J. Agric. Food Chem., 2006, 54 (12), pp 4284–4296.

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.

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

Women who eat plenty of green vegetables may decrease their risk of nuclear cataracts. Nuclear cataract is the most common type of cataract among older Americans.

Authors of the Carotenoids in Age-Related Disease Study (CAREDS) report that women with diets high in lutein and zeaxanthin have a lower prevalence of nuclear cataract. Lutein and zeaxanthin are nutrients found in green vegetables such as spinach, kale, turnip greens and broccoli. Learn more about good sources of lutein and zeaxanthin.

Participants in this study were 1082 women with intakes of lutein and zeaxanthin above the 78th (high) or below the 28th (low) percentile. These women (from Iowa, Wisconsin and Oregon) ranged in age from 50 to 79.

Researchers evaluated associations between nuclear cataracts and lutein and zeaxanthin in the diet and serum of patients. Nuclear cataract was determined from slitlamp photographs. Lutein and zeaxanthin the diet were estimated from a validated, semi-quantitative food frequency questionnaire. Serum levels of lutein, zeaxanthin and tocopherols were determined at Tufts University by a reverse-phase HPLC analysis.

Women in the group with high dietary levels of lutein and zeaxanthin had a 23% lower prevalence of nuclear cataract compared with the low level group.

In 2006 the authors of CAREDS found that a stable intake of lutein and zeaxanthin over time could also reduce the risk of AMD in healthy women. Read more about the results of this study.

Read more about cataracts

Review other studies on cataracts

Learn about natural products for cataracts

SOURCE: Associations Between Age-Related Nuclear Cataract and Lutein and Zeaxanthin in the Diet and Serum in the Carotenoids in the Age-Related Eye Disease Study (CAREDS), an Ancillary Study of the Women’s Health Initiative, Moeller et al, Arch Ophthalmol. 2008; 126(3): 354-364.