Special Diets

• By Jane Hart, MD

Lutein Slows Vision Loss

A diet rich in dark-green leafy vegetables is essential for eye health, and specific nutrients such as lutein that are found in these foods may have particular benefits for people who suffer from eye disorders. A study in the Archives of Ophthalmology suggests that supplementing with lutein may slow vision loss in people who suffer from an eye disease known as retinitis pigmentosa.

Lutein is important for healthy vision and is found in dark-green leafy vegetables such as lettuce, kale, and spinach

Lutein plus vitamin A protects peripheral vision

Retinitis pigmentosa refers to a group of hereditary diseases that affect the retina of the eye. The condition often starts in adolescence and slowly progresses through adulthood leading to partial vision loss or sometimes blindness.

In this study, 225 non-smoking people aged 18 to 60 who had retinitis pigmentosa were randomly assigned to receive 12 mg of lutein or a control tablet (providing no treatment), and all participants received daily vitamin A (as 15,000 IU of retinyl palmitate). During the first year of the study participants were also advised to eat two 3-ounce servings of oily fish per week after a study showed benefit of DHA (docosahexaenoic acid) supplementation for retinitis pigmentosa.

Researchers followed the people in the study for four years, collecting information from annual eye exams and monitoring of blood serum lutein levels. Results showed:

• People who took lutein had a slower decline of side (midperipheral) vision loss compared with the control group. Vision loss was significantly slower among those with the highest serum lutein levels compared with those who had the lowest.
• There was no significant difference or treatment effect on the course of degeneration of central vision loss between the lutein and control group.

The study authors point out that a daily dietary recommendation for lutein has not been established and that most Americans eat 1 to 2 mg per day. Prior studies, however, have shown that 6 mg per day of lutein supplementation is associated with a reduced risk of cataracts and age-related macular degeneration.

The long-term safety of taking lutein supplementation has yet to be established. There are also a number of risks of taking high-dose vitamin A, so it is important to check with your doctor before taking dietary supplements in order to learn more about the risks and benefits.

Tips for eye health

• Eat a balanced diet. Along with other nutrients, lutein is important for healthy vision and is found in dark-green leafy vegetables such as lettuce, kale, and spinach. This study is another good reason to strive for those five servings of fruits and vegetables every day.
• Avoid unhealthy lifestyle behaviors. Smoking and drinking alcohol in excess may damage eye health, and both habits are also associated with lower serum lutein levels according to the study authors.
• Wear sunglasses. Ultraviolet light from the sun can be damaging to healthy eyes but especially for people who suffer from eye disorders. Wear protective glasses and provide glasses for your children while enjoying the sunny outdoors.