Dr. Grossman’s Blog

Sometimes those bits of wisdom that “everybody knows” just have to be true.  In this case, yes, carrots really are good for your eyes.

A report at the recent American Academy of Ophthalmology (AAO) – Middle East-Africa Council of Ophthalmology (MEACO) Joint Meeting described how beta carotene can help people with retinitis pigmentosa.

Image via maine.gov

Retinitis pigmentosa is a hereditary disease most often marked by the onset of nightblindness during childhood that eventually leads to a loss of peripheral and eventually in many cases blindness.  Previous research has shown beta carotene, 9-cis, can help treat night blindness.  In this study, one third of the retinitis pigmentosa patients under observation showed improved visual function after taking a beta carotene supplement for 90 days. Source: http://www.medicalnewstoday.com/articles/204979.php

Learn more about other natural therapies for retinitis pigmentosa at our website.

For further information on how the nutrients in food can help eye health and overall health, check out this page.

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.

Age-related macular degeneration (AMD) is the most prevalent cause of irreversible blindness in developed countries. Researchers have shown that high dietary intake of beta carotene, vitamins C and E, and zinc may substantially reduce the risk of AMD.

Scientists at the Erasmus Medical Centre in the Netherlands investigated whether regular dietary intake of antioxidants is associated with a lower risk of incident AMD.

Participants in the study included 7983 inhabitants aged 55 years or older in a middle-class suburb of Rotterdam, the Netherlands. A baseline home interview and a series of examinations at the study center were conducted from 1990 until 2004. Food intake was assessed with a food questionnaire, and participants were evaluated for incident AMD (defined as soft distinct drusen with pigment alterations, indistinct or reticular drusen, geographic atrophy, or choroidal neovascularization). Incident AMD occurred in 560 participants after follow-up exams (conducted 8 years later, on average).

Study results showed that participants who consumed vitamin E and zinc were less likely to have AMD.

An above-median consumption of all 4 nutrients studied (beta carotene, vitamin C, vitamin E, and zinc) was associated with a 35% reduced risk of AMD.

Learn more about macular degeneration (AMD)

Find excellent food sources for beta carotene, vitamin C, vitamin E and zinc

SOURCE: Dietary intake of antioxidants and risk of age-related macular degeneration, Leeuwen et al, JAMA, 2005 Dec 28;294 (24):3101-7.

Cataracts are the leading cause of blindness around the world.  Studies suggest that oxidation is responsible for much of the damage to the lens and that antioxidants might protect the lens against formation of cataract.

Scientists at the University of Sydney and the University of Melbourne in Australia have released their investigation of the relationship between antioxidant nutrient intakes and the incidence of age-related cataract.

During 1992–1994, 3654 people aged 49 years or older attended baseline examinations as part of the Blue Mountains Eye Study.  Of these, 2464 (67.4%) of the participants were evaluated again at either 5 years or 10 years.  At each examination, lens photography was performed and food-frequency questionnaires were administered.  Antioxidants, including beta-carotene, zinc, and vitamins A, C, and E, were assessed. Cataract was assessed at each examination from lens photographs with the use of the Wisconsin Cataract Grading System.

Participants whose total intake of vitamin C (diet as well as supplements) was in the top 20% of the group had a reduced risk of nuclear cataract.  An above-median intake of combined antioxidants (vitamins C and E, beta-carotene, and zinc) was also associated with a reduced risk of incident nuclear cataract. 

Study authors concluded that higher intakes of vitamin C or the combined intake of antioxidants had long-term protective associations against development of nuclear cataract in this older population.

Learn more about antioxidants and their importance for good eye health

Read more about cataracts

SOURCE:  Tan, et al, Antioxidant nutrient intake and the long-term incidence of age-related cataract: the Blue Mountains Eye Study,  American Journal of Clinical Nutrition, Vol. 87, No. 6, 1899-1905, June 2008.

At the American Glaucoma Society meeting, Dr. JoAnn A. Giaconi reported that women who reported eating greater amounts of fruits and vegetables appeared to have a lower likelihood of developing glaucoma.

The foods that seemed especially protective included fresh oranges, peaches, spinach, collard greens, and kale.

Dr. Giaconi presented results from a review of data from the Study of Osteoporotic Fractures.  In this study involving a subset of 584 black women, glaucoma was diagnosed in at least one eye in 77 participants.  Disc photos and suprathreshold visual fields were evaluated in conjunction with Block Food Frequency Questionnaires on the participants’daily food consumption.

The results?

• Eating three or more servings of fruit or fruit juices daily decreased the odds of black women developing glaucoma by 79%
• Eating one serving of collard greens or kale decreased the odds of glaucoma by 57%
• Eating more than two servings per week of fresh oranges and peaches also significantly decreased the chance of developing glaucoma.

Researchers believe that the antioxidants in fruits and vegetables (vitamin A, alpha- and beta-carotene, folate, lutein, zeaxanthin) can potentially block oxidation stress that can lead to cell damage in glaucoma.

Read other studies about the benefits of consuming antioxidants

SOURCE:  Giaconi JA, et al. Nutritional associations with glaucoma among older black women. Paper presented at: The 18th Annual AGS Meeting; March 8, 2008; Washington, DC.

A study conducted in North India found that people with low levels of antioxidants had higher levels of cataracts.

Several recent studies have shown antioxidants are important in fighting macular degeneration. We are now learning how important these same antioxidants may be for preventing cataracts as well.

How can you boost your antioxidant levels? Eat more fruits and vegetables, especially those high in yellow, orange and dark green pigments.

In this new study 1,112 participants aged 50 or older were interviewed for risk factors (tobacco, alcohol, biomass fuel use, sunlight exposure and socioeconomic status) and underwent lens photography and blood sampling to measure antioxidant levels.

Researchers found significant inverse associations between cataracts and the antioxidants vitamin C, zeaxanthin, lutein, lycopene, alpha- and beta-carotene and beta-cryptoxanthin; people with lower levels of these antioxidants had higher rates of cataracts.

Read more about antioxidants

Learn more about cataracts

Learn more about food sources for nutrients crucial for good eye health

Read more research on antioxidants and their importance for vision

SOURCE: Dherani M, Murthy GV, Gupta SK, et al. Blood levels of vitamin C, carotenoids and retinol are inversely associated with cataract in a North Indian population. Invest Ophthalmol Vis Sci 2008;49(8):3328-35.

Studies done by researchers in England in the late 90’s found that eating a diet with sufficient amounts of the anti-oxidant carotenoids such as alpha- and beta-carotene, lycopene, and lutein reduced the risk of certain types of cataracts. These researchers found:

• People with the highest blood concentrations of either alpha- or beta-carotene were 30-50% less likely to develop “nuclear cataracts”—those cataracts located in the center (the nucleus) of the lens.
• People with high blood levels of lycopene (found in high concentrations in cooked tomatoes) were associated with a 60% lower risk of “cortical cataracts”—those cataracts located in the outer layer of the lens. (Are those Italians on to something?)
• And people with high lutein concentrations were 50% less likely to develop “posterior subcapular cataracts”—those cataracts located toward the bottom rear of the lens.

The study shows that a diet rich in antioxidants can reduce the risk of cataracts. So what are carotenoids? Carotenoids are yellow, orange, and red pigments synthesized by plants. Common foods highest in alpha- and beta-carotene are:

• Pumpkin
• Carrots and carrot juice.
• (And for beta-carotene add sweet potato.)

Carotenoids are best absorbed with fat in a meal. Chopping, pureeing, and cooking carotenoid-containing vegetables in oil generally increases the bioavailability of the carotenoids they contain.

Common foods highest in Lutein are:

• Spinach
• Kale
• Collards

Also, interestingly enough, several epidemiological studies found that men with high intakes of lycopene from tomatoes and tomato products were less likely to develop prostate cancer than men with low intakes.

More and more it seems modern science is finding out what mothers have known for centuries … Eat your vegetables. They’re good for you!

You can also read what others say about natural products that help cataracts.

References: Gale CR, Hall NF, Phillips DI, et al. “Plasma antioxidant vitamins and carotenoids and age-related cataract.” Ophthalmology, 2001;108:1992-1998.

Jacques PF, Chylack LT. Jr., Hankinson SE, et al. “Long-term nutrient intake and early age-related nuclear lens opacities,” Archives of Ophthalmology, 2001;119:1009-1019.

Jane Higdon, Ph.D., Linus Pauling Institute, Oregon State University, “Carotenoids—Alpha-Carotene, Beta-Carotene, Beta-Cryptoxanthin, Lycopene, Lutein and Zeaxanthin.”