Age-related macular degeneration: risk factors and prevention

AGE-RELATED MACULAR DEGENERATION: RISK FACTORS AND PREVENTION

Neva Cochran, MS, RDN, LD | May 22, 2019

Moms have long encouraged kids to eat their carrots for eye health. Carrots are a rich source of beta-carotene, a precursor of vitamin A that can help prevent night blindness, or the inability to see clearly when going from bright to dim light. Two eye nutrients similar to beta-carotene – and not on most moms' lists for eye health – are lutein and zeaxanthin. These yellow-colored compounds, as part of a supplement formula given in a clinical trial known as AREDS2, may help reduce the progression of age-related macular degeneration (AMD).

WHAT IS MACULAR DEGENERATION?

Age-related macular degeneration (AMD) is a progressive eye disease and a leading cause of blindness worldwide. In this condition, the central part of the eye’s retina, the macula, deteriorates. The macula controls the ability to read, drive a car, recognize faces, identify colors and see objects in fine detail.¹ By 2020, an estimated 196 million individuals are projected to suffer from AMD across the globe.²

The macula is yellow from the lutein and zeaxanthin it contains. The two nutrients protect the eye from oxygen damage due to ultraviolet and blue light. The more lutein and zeaxanthin in the yellow spot of the eye, known as macular pigment optical density, the more protection for the eyes.³

WHAT CAUSES MACULAR DEGENERATION?

While there are several risk factors for AMD, the most significant one is aging, with most people developing AMD after they turn 55. Additional risk factors include some that we are born with and unable to change and others that we can control.⁴

Uncontrollable

Genetics: Those with a family history of AMD have a greater risk.
Race: Caucasians are more likely than African- Americans or Hispanics to have AMD.
Light-colored irises in the eye
Far-sightedness
Gender: Women are more likely to develop AMD because they live longer.

Controllable

Smoking: Cigarette smoking is linked to significantly lower levels of yellow pigment in the eye⁵directly related to the amount of lutein and zeaxanthin in the macula. Smoking may reduce the amount of oxygen delivered to the eye, increase damaging chemicals and lower the amount of protective nutrients carried by the blood to the eye.⁶
Consuming more of some types of fat, particularly vegetable, monounsaturated and polyunsaturated fats, may increase risk for AMD especially in foods such as commercially prepared pie or cake. Eating more omega-3 fats found in fish like tuna and salmon may lower your risk.⁷
Some medications can impair eyesight.⁸
Being overweight overall and around the abdomen
Untreated heart disease or high blood pressure
Long-term exposure to the sun without eye protection. Ultra-violet and blue light from the sun or other sources can cause significant damage to the retina. And low levels of yellow pigment in the macula can allow greater blue light damage.¹⁰

Long-term exposure to the sun without eye protection. Ultra-violet and blue light from the sun or other sources can cause significant damage to the retina. And low levels of yellow pigment in the macula can allow greater blue light damage.⁹

WHAT CAN BE DONE TO REDUCE THE RISK OF DEVELOPING MACULAR DEGENERATION?

While you can’t change your family, gender, race or eye color, there are several AMD risk factors you can control. Stopping smoking is one of them. The good news is that studies show former smokers have only slightly more risk for developing AMD compared with those who have never smoked.⁶ If you have heart disease or high blood pressure, make sure you are seeing a doctor and following their advice for managing it. Also, check with your physician about any medications you are taking that might increase your chances for AMD.

Protect your eyes from the sun. UV protective eyewear is a must and is available in both eye correction lenses and sunglasses.

Likewise, if you are carrying around extra weight, cut calories and participate in more physical activity that you enjoy. Also, eating fish high in omega-3 fats like tuna and salmon two to three times a week and more green, leafy vegetables may help protect eyes from AMD. You may want to consult a registered dietitian nutritionist for an eating plan appropriate for your lifestyle and food preferences.

WHAT ABOUT SUPPLEMENTS FOR MACULAR DEGENERATION?

Launched in 1992, the Age-Related Eye Disease Study (AREDS) evaluated the daily intake of vitamins E and C, beta-carotene and zinc on AMD. In 2001, researchers reported that the AREDS formula reduced the risk of advanced AMD by about 25 percent over a five-year period.¹⁰

An additional study, AREDS2, was started in 2006 to determine, among other goals, if adding lutein and zeaxanthin to the original AREDS formula would be better for lowering risk of advanced AMD. Participants who took the formula with lutein and zeaxanthin in place of beta-carotene reduced their risk of developing advanced AMD over the five years by about 18 percent, compared with participants who took a supplement with beta-carotene but no lutein or zeaxanthin.¹¹ In addition, results showed a 26 percent reduction in the risk of progression to AMD beyond the effects of the previous standard of care in people with the lowest diet intakes of lutein and zeaxanthin compared to those at the highest intakes.

Taking a supplement may be a good idea to further reduce your risk for AMD along with a healthy diet, more activity, protecting eyes from the sun and not smoking. Check with your doctor to learn more about the right supplement for you.