In the November 9, 1994 Volume 272 issue of the Journal of the American Medical Association, an important article was published that showed people who eat spinach 5 or more times a week have a greatly reduced incidence of age-related macular degeneration. The following is the abstract of that article:
Johanna M. Seddon, MD; Umed A. Ajani, MBBS; Robert D. Sperduto, MD; Rita Hiller, MS; Norman Blair, MD; Thomas C. Burton, MD; Marilyn D. Farber, PhD; Evangelos S. Gragoudas, MD; Julia Haller, MD; Dayton D. Miller, PhD; Lawrence A. Yannuzzi, MD; Walter Willett, MD; for the Eye Disease Case-Control Study Group
Objective: To evaluate the relationships between dietary
intake of carotenoids and vitamins A, C, and E and the risk of neovascular
age-related macular degeneration (AMD), the leading cause of irreversible
blindness among adults.
Design: The multicenter Eye Disease Case-Control Study.
Setting: Five ophthalmology centers in the United States.
Patients: A total of 356 case subjects who were diagnosed with
the advanced stage of age-related macular degeneration within 1 year prior to
their enrollment, aged 55 to 80 years, and residing near a participating
clinical center. The 520 control subjects were from the same geographic areas as
the case subjects, had other ocular diseases, and were frequency matched to
cases according to age and sex.
Main Outcome Measures: The relative risk for age related
macular degeneration was estimated according to dietary indicators of
antioxidants status, controlling for smoking and other risk factors, by using
multiple logistic-regression analyses.
Results: A higher dietary intake of carotenoids was associated
with a lower risk for age-related macular degeneration. Adjusting for other risk
factors for age-related macular degeneration, we found that those in the highest
quintile of carotenoid intake had a 43% lower risk for age-related macular
degeneration compared with those in the lowest quintile (odds ratio, 0.57; 95%
confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific
carotenoids, lutein and zeaxanthin, which are primarily obtained from dark
green, leafy vegetables, were most strongly associated with a reduced risk for
age-related macular degeneration (P for trend = .01).
Several food items rich in carotenoids were
inversely associated with age-related macular degeneration. In particular, a
higher frequency of intake of spinach or collard greens was associated with a
substantially lower risk for age-related macular degeneration (P for trend
< .001). The intake of performed vitamin A (retinol) was not
appreciably related to age-related macular degeneration. Neither vitamin E nor
total vitamin C consumption was associated with a statistically significant
reduced risk of age-related macular degeneration, although a possibly lower risk
for age-related macular degeneration was suggested among those with higher
intake of vitamin C, particularly from foods.
Conclusion: Increasing the consumption of foods rich in
certain carotenoids, in particular dark green, leafy vegetables, may decrease
the risk of developing advanced or exudative age-related macular degeneration,
the most visually disabling form of macular degeneration among older people.
These findings support the need for further studies of this relationship.