ARM, a degenerative disorder of the central part of the retina, is the leading cause of vision loss among people 65 and older. The late stages of ARM, geographic atrophy, and neovascular (disciform) degeneration, are called age-related macular degeneration (AMD), and result in severe and irreversible visual impairment that affects approximately 25-30 million people.
Some scientific evidence suggests that excessive exposure to light, particularly blue light, is associated with age-related macular degeneration. There are currently limited effective treatments for ARM, and so prevention of this eye disease has turned towards antioxidant vitamin and mineral supplementation that has been found to help protect against the disease.
The latest findings from this large study suggest that a dietary regime packed with fruit could combat the progression of this debilitating disease.
Researcher Eunyoung Cho at the Brigham and Women's Hospital, Boston, and colleagues examined the effect of antioxidant vitamins and carotenoids - compounds responsible for the red, yellow and orange pigments found in some fruits and vegetables - as well as fruits and vegetables on the development of ARM among 77,562 women and 40,866 men.
The women were part of the Nurses' Health study, and the men were participants in the Health Professionals Follow-up study. Participants were at least 50 years old at the beginning of the study with no diagnosis of ARM. Women were followed for up to 18 years, and men were followed for up to 12 years.
Women completed food consumption questionnaires up to five times over the follow-up period (in 1980, 1984, 1986, 1990 and 1994), and men answered similar questionnaires up to three times over the follow-up period (in 1986, 1990, and 1994). Participants also reported their vitamin and supplement use once every two years.
Over the follow-up period, the researchers documented a total of 464 (329 women and 135 men) new cases of early stage ARM, and 316 (217 women and 99 men) cases of neovascular ARM (a more severe type of ARM).
The researchers found that fruit consumption was inversely associated with risk of neovascular ARM, and participants who ate three or more servings per day of fruit had a 36 per cent lower risk of ARM compared to participants who reported eating less than 1.5 servings per day. These findings were similar for men and women.
"None of the antioxidant vitamins and carotenoids were strongly related to either early or neovascular ARM risk, although many of them, including total carotenoids, had a suggestive inverse association with neovascular ARM risk," the researchers write.
Previous research has linked low levels of lutein and zeaxanthin - carotenoids found in dark green, leafy vegetables such as spinach and kale - to risk of age-related macular degeneration.
Full findings are published in the June issue of the Archives of Ophthalmology, a JAMA/Archives journal.