Dr. Grossman’s Blog

Researchers from Tufts University have found that a diet rich in omega-3 fatty acids and low in starchy carbohydrates can significantly reduce the risk of age-related macular degeneration (AMD).

The study, published in the journal Ophthalmology, is the first to calculate the combined effect of specific dietary nutrients and eating habits on a person’s risk for age-related macular degeneration.

During the study of 4003 participants in the ongoing Age-Related Eye Disease Study (AREDS), each dietary factor was assigned a percentile score; these scores were accumulated to find each participant’s compound score. The compound score was then evaluated for its association with the risk of AMD.

Researchers showed that vitamins C and E, zinc, lutein, zeaxanthin and the omega-3 fatty acids known as D.H.A. and E.P.A. were linked to lower risk for AMD.

The lowest risk of AMD was found in participants who regularly consumed a combination of these nutrients as part of a low-glycemic index diet.

The glycemic index (GI) is a measure of the effects of carbohydrates on blood glucose levels. Carbohydrates that break down rapidly during digestion, such as white bread and pastries, have a higher GI, as they release glucose into the bloodstream rapidly. Foods that break down more slowly, such as vegetables and proteins, have a lower GI value.

Read more about AMD on the Natural Eye Care website

Learn more about food sources for nutrients important for good eye health, including omega-3 fatty acids

SOURCE: “Dietary Compound Score and Risk of Age-Related Macular Degeneration in the Age-Related Eye Disease Study”, Chiu, et al, Ophthalmology, Volume 116, Issue 5, Pages 939-946.

Scientists have long known that our diets influence our risk of age-related macular degeneration (AMD).  High glycemic-index diets have now been identified as a risk factor for AMD by researchers from the University of Sydney and the University of Melbourne in Australia, and the National University of Singapore.

The glycemic index (GI) is a measure of the effects of carbohydrates on blood glucose levels.  Carbohydrates that break down rapidly during digestion releasing glucose rapidly into the bloodstream have a high GI; carbohydrates that break down slowly, releasing glucose gradually into the bloodstream, have a low GI.

Scientists examined the association between the dietary glycemic index and the incidence of AMD in the Blue Mountain Eye Study population.

During 1992–1994, 3654 people aged 49 years or older attended baseline examinations.  Of these, 2335 patients were reexamined after 5 years and 1952 were examined again after 10 years.  At each examination, lens photography was performed and food-frequency questionnaires were administered.  An Australian database was used to calculate the mean glycemic index.

Over 10 years, 208 of 1810 participants developed early AMD. After adjusting for age, smoking, and other risk factors, a higher mean dietary glycemic index was associated with an increased risk of early AMD. 

Conversely, a greater consumption of predominantly lower glycemic index foods was associated with a reduced risk of incident early AMD. No relation was observed with late AMD.

Researchers concluded that a high-glycemic-index diet is a risk factor for early AMD, but they also noted that low glycemic-index foods such as oatmeal may protect against early AMD.

Learn more about the glycemic index and use a free GI database to find the GI index of your favorite carbohydrates at this University of Sydney Glycemic Index web site

SOURCE:  Kaushik, et al, Dietary glycemic index and the risk of age-related macular degeneration,  American Journal of Clinical Nutrition, Vol. 88, No. 4, 1104-1110, October 2008.