Anti-Aging Nutrition for Eyes

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As people age, they’re even more afraid of losing their vision than their memory, says a survey by the American Optometric Association. Risk of potentially sight-robbing eye diseases does increase as we get older. Age-related macular degeneration (AMD), cataracts and glaucoma are three top concerns. They can affect your quality of life and independence. You can help protect your vision by getting regular comprehensive eye exams and following a healthy diet and lifestyle, including staying physically active and managing your weight.

“When possible, prevention of age-related eye diseases is preferred to treatment and remediation,” says Chung-Jung Chiu, DDS, PhD, a scientist in Tufts’ HNRCA Nutrition and Vision Research Laboratory. “Many studies have consistently found that diet plays a major role in eye health.” Although diet plays a particularly important role in AMD, some evidence suggests nutrition may play a role in cataracts and glaucoma, too.

Age-Related Macular Degeneration:

AMD is most likely to occur after age 60 and damages the macula of the eye. That’s the part needed for sharp central vision important for reading, driving and recognizing faces. In the advanced stage, AMD is the cause of more than 50% of cases of legal blindness (no better than 20/200 corrected vision in your better-seeing eye) in the US.

“Current treatments for AMD are costly, can arrest only the neovascular (‘wet’) type of advanced AMD and don’t prevent progression of vision loss,” Chiu says. Treatment includes medication (called anti-VEGF) and possibly laser surgery. There are no treatments for the other type of advanced macular degeneration, “dry” AMD, which accounts for about 90% of all advanced AMD cases but progresses more slowly.

Diet. “About 70% of the risk for AMD is due to heredity,” says Emily Y. Chew, MD, the deputy clinical director at the National Eye Institute at the National Institutes of Health. “The good news is that a healthy diet may help offset AMD genetics.”

Research from Chiu and his colleagues at Tufts has shown that a Western-style diet – with its high content of foods like red and processed meats, refined grains and sweets – is associated with increased risk of AMD. In contrast, a dietary pattern rich in vegetables (particularly dark-yellow vegetables, leafy greens, tomatoes and cruciferous vegetables like broccoli), legumes, fruit, whole grains and seafood is associated with lower AMD risk.

Supplements. The well-known Age-Related Eye Disease Study (AREDS), a large nationwide, placebo-controlled trial, showed that supplementation with certain vitamins and minerals (vitamin C, vitamin E, beta carotene, zinc and copper) reduced the risk of advanced AMD by about 25% over a five-year period compared to placebo. The study involved more than 3,600 adults ages 55 to 80.

The AREDS study was followed by AREDS2, which tested variations of the original supplement. Instead of beta carotene (which is linked with increased risk of lung cancer in smokers when supplemented), two other carotenoids with strong links to eye health – lutein and zeaxanthin – were used. This substitution was found to be just as effective as beta carotene and avoided the cancer concern, so AREDS2 supplements use lutein and zeaxanthin.

The American Academy of Ophthalmology notes that there is no evidence to support the use of AREDS supplements in people who have less than intermediate AMD. So, check with your eye doctor before taking a supplement.

Cataracts:

These develop when proteins in the lens of the eye become damaged, resulting in blurry, hazy vision. Surgical removal is the only available treatment. If untreated, cataracts may lead to blindness.

By age 80, more than half of all Americans either have a cataract or have had cataract surgery. Getting older is a significant risk factor, while genetics may account for about 35% of risk. Protecting your eyes from sunlight is a factor, too.

Diet. Chew says an antioxidant-rich diet is associated with decreased risk of cataract in observational studies, but this hasn’t been proven in a trial. Vitamin C has been a focus of age-related cataract research, partly because high amounts of the nutrient are found in the lens and watery fluids that surround the lens of the eye.

Scientists from King’s College London in the UK led a recent 10-year observational study on nutrient intake and progression of nuclear cataract (the most common type) in 324 female twins, average age 62 at the study start. The highest intake of vitamin C (up to about twice the RDA) from food was associated with a 33% decreased risk of cataract progression over 10 years of follow-up compared to the lowest dietary intake of vitamin C. The study was published in Ophthalmology.

The study can’t show cause and effect, but even for general good health it’s wise to eat nutritious vitamin C-rich foods, which are typically fruits and vegetables, like oranges, bell peppers and broccoli. Don’t use supplements as a shortcut to getting your vitamin C, however. The data aren’t consistent as to whether or not vitamin C supplements help cataracts. Other nutrients and phytochemicals beyond vitamin C in fruits and vegetables may have contributed to the protection observed.

Supplements. “We looked at cataracts in our AREDs supplement trials (which included vitamin C), but we didn’t find a treatment effect,” Chew says. However, the AREDS2 research did suggest that people with the lowest dietary intake of lutein and zeaxanthin may benefit from supplementing these carotenoids. Within that subgroup, lutein and zeaxanthin supplementation was associated with a 32% reduction in progression to needing cataract surgery, compared to placebo pills. Of course, you can also increase your lutein and zeaxanthin intake by eating foods like orange bell peppers, kale, spinach, zucchini, kiwi and eggs (yolks).

Glaucoma:

Risk of glaucoma increases after age 60, but it can develop earlier. In the most common form, called primary open angle glaucoma, vision is eroded slowly and initially undetectably. It starts with the side (peripheral) vision and slowly moves in toward the center of your visual field—potentially resulting in blindness.

“Compared to other major causes of age-related blindness, particularly AMD, the link between diet and lifestyle factors and glaucoma risk is not strong,” says Jae Hee Kang, DSc, an assistant professor of medicine at Brigham and Women’s Hospital and Harvard T.H. Chan School of Public Health in Boston. “And, studies to evaluate the association between diet and glaucoma have been relatively scarce.”

Genetics, however, are important. “Having a family history of glaucoma increases a person’s risk of glaucoma by about two-fold or more,” Kang says. “Currently, the best way to address glaucoma is to get regular eye exams so it can be caught early and managed with various treatments,” Kang says.

Glaucoma treatments typically consist of prescription eye drops, laser therapies and surgical procedures to lower eye pressure and improve fluid drainage. If the fluid pressure in the eye (called intraocular pressure or IOP) is too high, the extra pressure can wear away at the optic nerve, damaging the nerve cells required for vision. However, some people get glaucoma even if their IOP is normal (generally defined as 12 to 21 mm Hg). And, you won’t necessarily get glaucoma if your IOP is elevated; it’s just a risk factor.

Diet. An active area of research in diet and glaucoma is nitrate intake. Preliminary research suggests a higher intake of naturally nitrate-rich vegetables, like leafy greens and beets, may be protective against glaucoma. Nitrate can be converted to nitric oxide in the body. “Nitric oxide is a signaling molecule and a gas that helps maintain optimal blood flow and may be important for keeping eye pressure low,” Kang says. “In primary open-angle glaucoma, nitric oxide signaling may be impaired.”

In a large study of more than 100,000 men and women (initially glaucoma-free, ages 40 and older) followed for more than 25 years, Kang and colleagues observed that eating 1 cups versus 1⁄3 cup a day of leafy green vegetables (such as romaine lettuce, kale, spinach, chard and mustard greens) was associated with a 20 to 30% decreased risk of developing primary open angle glaucoma (after accounting for other nutrients in the vegetables). Although encouraging, the study can’t show cause and effect. And, Kang emphasizes that further research is needed to confirm these findings. The study was published in JAMA Ophthalmology.

Taking a step back to look at dietary aspects associated with protection against age-related eye diseases, eating plenty of fruits and vegetables appears to be a common thread. It’s uncertain whether the eye benefits are due to the fruits and vegetables themselves or their replacement of unhealthful foods. However, it ultimately doesn’t matter. Fruits and vegetables are good for many aspects of health beyond vision, so enjoy a variety of these colorful gems daily.

To learn more: Investigative Ophthalmology & Visual Science, March 2017

To learn more: National Eye Institute, Questions and Answers About AREDS2

To learn more: Ophthalmology, June 2016

To learn more: JAMA Ophthalmology, March 2016

TAKE CHARGE!

Tips for taking care of your eyes as you age include:

– Get a comprehensive dilated eye exam every 1 to 2 years if youÂ’re age 65 or older.
The doctor will widen the pupil of the eye with eye drops to get a closer look at the inside of the eye. This is needed to diagnose age-related macular degeneration (AMD), cataract and glaucoma early, before significant damage happens.

– Eat an eye-healthy diet.
It should include at least 2½ cups of colorful vegetables (like leafy greens and tomatoes) and 2 cups fruit daily. Also aim to eat 4 ounces omega-3 rich fish (like salmon and sardines) at least twice a week, as well as other healthful foods like whole grains and legumes.

– Limit refined carbohydrates.
Foods such as white bread, sugary drinks and desserts can rapidly increase your blood sugar level. That may contribute to inflammation and accumulation of damaged proteins in the eye in AMD and cataract.

– Maintain a healthy weight.
Excess weight is associated with increased risk of AMD and cataract.

– Get daily exercise.
Moderate aerobic exercise, such as walking or bicycling, may benefit glaucoma by helping lower eye pressure. Exercise also can aid weight control, which may help lower risk of AMD and cataract, too.

– Protect eyes from sun.
Ultraviolet (UV) radiation exposure is an established risk factor for cataract. Wear sunglasses year-round, including cloudy days. Choose sunglasses that block 100% of UV rays.

– Don’t smoke.
It increases AMD and cataract risk.

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