How Foods Fortify Vision
Judi Ebbert, PhD, MPH, RN | Oct 13, 2016 Sept 12, 1993
We’ve all heard the banal saying “you are what you eat.” We’ve heard it so often, we pay it no mind. But we’re wise to heed study results that relate health benefits to behaviors associated with the intake of specific nutrients. We’ve been researching foods related to eye health, and evidence shows that the foods you eat can fortify your vision.
Have a heart for your eyes
Consider the American Academy of Ophthalmology’s (AAO’s) analogy between heart and eye health. Both organs benefit from similar foods because both have arteries that deliver essential oxygen and nutrients. Fats that clog arteries in the heart can travel to the eye and linger in the tiny arteries. Think of fats (such as high saturated fats and cholesterol found in fast or fried foods) as saboteurs. These take up space and contribute nothing beneficial.
Aging and eye disorders
Risk for eye disorders rises with age. The most prevalent disorders can cause a range of life-changing outcomes. Dry eye syndrome causes chronic discomfort. Cataracts, diabetic retinopathy, glaucoma, and macular degeneration can cause partial or total loss of vision. Can nutrients reduce risk for these disorders? Eye experts say yes. Let’s see how.
Dry eye syndrome (DES)
Tears flow freely for most people, thanks to lacrimal and Meibomian glands. But tears are meant for more than emotion. They wash the eye, remove dust, and reduce risk of infection. A tear is a drop of mucous inside water coated with oil. DES prevents tears and causes burning, pain, sensations of in-eye grit, blurring, and eye fatigue. That would make many cry — but what if we couldn’t?
DES and diet
The National Eye Institute (NEI) notes that some DES sufferers benefit from foods high in omega-3 fatty acids rich in EPA and DHA. Food sources are salmon, tuna, mackerel, oysters, caviar, fish oil, flaxseed oil, walnuts, and soybeans. Others speculate that the antioxidants in colorful fruits (berries and cherries) and vegetables, especially dark leafy kale, spinach, and chard can help.
Age-related macular degeneration (AMD)
AMD is an insidious culprit that robs people of central vision. It is common in people over age 50. Damage occurs in the macula, the most sensitive part of the retina at the back of the eye. AMD won’t cause complete blindness, but it will impede the clear focus needed for driving, reading, writing, and close work.
Age-related macular degeneration
The American Optometric Association (AOA) explains that zinc is concentrated in the retina and blood vessels beneath it. A study of people at high risk for AMD who took 40-80 mg/day of zinc resulted in slowed progression by 25 percent and delayed visual acuity loss by 19 percent. Zinc plus antioxidants may help people with early AMD. Foods high in zinc include raw oysters, cooked red meats, and legumes such as chickpeas and red kidney beans.
Cataracts are the leading cause of blindness in people over 40. Age increases risk for progressive thickening of the lens, which gets cloudy and blocks light from entering the eye. Other cataract causes are eye diseases, prior eye surgery, heavy use of steroids, and chronic diseases such as diabetes. A cataract can be removed surgically and replaced with a lens implant, but can diet help?
Cataracts and diet
AOA includes diet as a risk factor for cataract development. With age comes more oxidation (damage by essential oxygen). Antioxidant vitamins C and E may delay the onset of cataracts. Vitamin C sources are citrus fruits, cherries and berries, sweet peppers, and spices such as coriander and thyme. Vitamin E sources are sunflower seeds, almonds, spinach, safflower oil, and wheat germ.
Evidence for the cataract-diet connection
The Nurses’ Health Study showed that lutein and zeaxanthin, carotenoids in carrots, sweet potatoes, red and orange peppers, tomatoes and more, reduced the need for surgery. The amount per day ranged from 6 mg to 6.9 mg. AOA advises five servings of fruits and vegetables each day to get 100 mg of vitamin C and 5 to 6 mg of carotenoids. Add two servings of nuts and seeds to get 8 to 14 mg of vitamin E.
Glaucoma is a silent and sinister invader and the second leading cause of blindness. Increased fluid pressure destroys the optic nerve, making it unable to carry visual data from the retina to the brain. Glaucoma treatment may include pills and eye drops, but side effects of the latter interfere with compliance. Medicated contact lenses are being tested and may be available in a few years.
Glaucoma and diet
Remember the earlier evidence from the Nurses’ Health Study that showed anti-cataract benefits from lutein and zeaxanthin? It also showed benefits for glaucoma. Foods rich in lutein and zeaxanthin include orange (carotenoid) sources such as carrots, sweet potatoes, red and orange peppers, and tomatoes. We can’t omit great green sources such as broccoli, brussels sprouts, collard greens, and kale.
Types 1 and 2 diabetes can damage blood vessels in the retina. It begins with no symptoms or mild ones, but it leads to blindness. Risk increases with length of time having diabetes, especially if blood sugar is not controlled. Surgery can slow or stop progression, but prevention requires controlled blood sugar via medication, diet, and exercise — and avoid alcohol and do not smoke.
Do you see the pattern yet?
Nutrition recommendations for vision health include foods rich in antioxidant vitamins, omega-3 fatty acids, lutein and zeaxanthin, and minerals. Sources are richly colored fruits and vegetables, nuts and seeds, legumes, cold-water fish such as salmon and halibut, and red meat in moderation. Take our advice and choose foods that will fortify your vision.