[PHNUTR-L] Antioxidants Associated with Reduced Risk of Age-Related Macular Degeneration

[Kathrynne Holden, MS, RD]

Colleagues, the following is FYI and does not necessarily reflect my own
opinion. I have no further knowledge of the topic. If you do not wish to
receive these posts, set your email filter to filter out any messages
coming from   @nutritionucanlivewith.com    and the program will remove
anything coming from me.
---------------------------------------------------------
Source: American Medical Association (AMA) 	  	
Released: Thu 22-Dec-2005, 16:00 ET
Embargo expired: Tue 27-Dec-2005, 16:00 ET
http://www.newswise.com/articles/view/516984/?sc=dwhp

Antioxidants Associated with Reduced Risk of Age-Related Macular 
Degeneration


Newswise — A diet with a high intake of beta carotene, vitamins C and E, 
and zinc is associated with a substantially reduced risk of age-related 
macular degeneration in elderly persons, according to a study in the 
December 28 issue of JAMA.

Age-related macular degeneration (AMD) is a degenerative disorder of the 
macula, the central part of the retina, and is the most common cause of 
irreversible blindness in developed countries, according to background 
information in the article. Late-stage AMD results in an inability to 
read, recognize faces, drive, or move freely. The prevalence of late AMD 
steeply increases with age, affecting 11.5 percent of white persons 
older than 80 years. In the absence of effective treatment for AMD, the 
number of patients severely disabled by late-stage AMD is expected to 
increase in the next 20 years by more than 50 percent to 3 million in 
the United States alone. Epidemiological studies evaluating both dietary 
intake and serum levels of antioxidant vitamins and AMD have provided 
conflicting results. One study (called AREDS) showed that supplements 
containing 5 to 13 times the recommended daily allowance of beta 
carotene, vitamins C and E, and zinc given to participants with early or 
single eye late AMD resulted in a 25 percent reduction in the 5-year 
progression to late AMD.

Redmer van Leeuwen, M.D., Ph.D., of Erasmus Medical Centre, Rotterdam, 
the Netherlands, and colleagues investigated whether antioxidants, as 
present in normal daily foods, play a role in the primary prevention of 
AMD. Dietary intake was assessed at baseline in the Rotterdam Study 
(1990-1993) using a semiquantitative food frequency questionnaire. 
Follow-up continued through 2004. The Rotterdam Study included 
inhabitants aged 55 years or older from a middle-class suburb of 
Rotterdam, the Netherlands. Of 5,836 persons at risk of AMD at baseline, 
4,765 had reliable dietary data and 4,170 participated in the follow-up.

Average follow-up of participants was 8.0 years. During this period, 560 
persons (13.4 percent) were diagnosed as having new AMD, the majority of 
whom had early-stage AMD. A significant inverse association was observed 
for intake of vitamin E, iron, and zinc. After adjustment, a 1-standard 
deviation increase in intake was associated with a reduced risk of AMD 
of 8 percent for vitamin E and 9 percent for zinc. An above-median 
(midpoint) intake of beta carotene, vitamins C and E, and zinc, compared 
with a below-median intake of at least 1 of these nutrients, was 
associated with a 35 percent reduced risk of AMD, adjusted for all 
potential confounders. In persons with a below-median intake of all 4 
nutrients, the risk of AMD was increased by 20 percent. Adding 
nutritional supplement users to the highest quartile of dietary intake 
did not change the results.

“This study suggests that the risk of AMD can be modified by diet; in 
particular, by dietary vitamin E and zinc. A higher intake of vitamin E 
can be achieved by consumption of whole grains, vegetable oil, eggs, and 
nuts. High concentrations of zinc can be found in meat, poultry, fish, 
whole grains, and dairy products. Carrots, kale, and spinach are the 
main suppliers of beta carotene, while vitamin C is found in citrus 
fruits and juices, green peppers, broccoli, and potatoes. Based on this 
study, foods high in these nutrients appear to be more important than 
nutritional supplements. Until more definitive data are available, this 
information may be useful to persons with signs of early AMD or to those 
with a strong family history of AMD. Although in need of confirmation, 
our observational data suggest that a high intake of specific 
antioxidants from a regular diet may delay the development of AMD,” the 
authors conclude.

(JAMA.2005; 294:3101-3107.
-- 
Kathrynne Holden, MS, RD < fivestar at nutritionucanlivewith.com >
"Ask the Parkinson Dietitian"  http://www.parkinson.org/
"Eat well, stay well with Parkinson's disease"
"Parkinson's disease: Guidelines for Medical Nutrition Therapy"
http://www.nutritionucanlivewith.com/