NOW Foods - Glycemic Index Shown to be Crucial in Preserving Eye Health

Glycemic Index Shown to be Crucial in Preserving Eye Health

By Greg Arnold, DC, CSCS, May 25, 2006, abstracted from “Dietary carbohydrate intake and glycemic index in relation to cortical and nuclear lens opacities in the Age-Related Eye Disease Study” in the June 2006 issue of the Journal of Nutrition

Started in September 1990, the Age-Related Eye Disease Study (AREDS) was a major research program to improve understanding of the risk factors, progression, and outcomes for Age-Related Macular Degeneration (AMD) and cataract.¹ These are currently the leading causesof irreversible visual impairment and blindness in the UnitedStates and other developed countries throughout the world.²

When the research ended in 1995, more than 25 studies were released. The risk factors they identified included smoking and high blood pressure,³ and low nutritional intake from zinc,⁴ vitamin E⁵ and antioxidants.⁶ The overwhelming finding from the AREDS was that “high levels of antioxidants and zinc significantly reduce the risk of advanced age-related macular degeneration (AMD) and its associated vision loss”.⁷

While more research found the benefits of antioxidants in helping preserve eye health,⁸ other research also found that foods such as walnuts⁹ and supplements such as fish oil¹⁰ may also help protect against AREDS.

Now a new study¹¹ has found that helping protect against AREDS and cataract may also lie in following a diet according to the glycemic index.

Found to help protect against type 2 diabetes and cancer, the glycemic index was introduced in 1981 and is designed to help stabilize blood sugar levels which has been regarded as the most important factor in obesity and chronic disease.¹² Fortunately, there are many resources available to look up the GI of many different types of foods.¹³

In the study, researchers used data from food-frequency questionnaires was usedto obtain dietary information from 3,377 participants in the AREDS. Researchers measured lens cloudiness, the first signs of AMD and cataract, using the AREDS System for ClassifyingCataracts.¹⁴ They found that those consuming high GI foods had a 29% increased risk for either AMD or cataract compared to those consuming low GI foods.

These results led the researchers to conclude that “dietary glycemic quality and dietarycarbohydrate quantity may be associated with prevalent nuclearand cortical opacities.”

Greg Arnold is a Chiropractic Physician practicing in Danville, CA. You can contact Dr. Arnold directly by emailing him at mailto:ChiroDocPSUalum@msn.com or visiting his website www.CompleteChiropracticHealthcare.com

Reference:

¹ “Age-Related Eye Disease Study” posted on ClinicalTrials.gov www.clinicaltrials.gov/ct/show/NCT00000145

² National Advisory Eye Council. Vision Research—A National Plan: 1999-2003, Vol. 1. A Report of the National Advisory Eye Council. Bethesda, Md: National Institutes of Health; 1999. NIH publication 98-4120

³ AREDS Research Study Group. Risk factors associated with age-related macular degeneration. A case-control study in the age-related eye disease study: Age-Related Eye Disease Study Report Number 3. Ophthalmology. 2000 Dec;107(12):2224-32.

⁴ Clemons TE. Associations of mortality with ocular disorders and an intervention of high-dose antioxidants and zinc in the Age-Related Eye Disease Study: AREDS Report No. 13. Arch Ophthalmol. 2004 May;122(5):716-26.

⁵ Chew EY. Vitamin E and the age-related eye disease study supplementation for age-related macular degeneration. Arch Ophthalmol. 2005 Mar;123(3):395-6.

⁶ AREDS Research Study Group. The Age-Related Eye Disease Study: a clinical trial of zinc and antioxidants--Age-Related Eye Disease Study Report No. 2. J Nutr. 2000 May;130(5S Suppl):1516S-9S

⁷ “Age-Related Eye Disease Study Results” posted on the National Eye Institute Website www.nei.nih.gov/amd/pr.asp

⁸ Van Leeuwen. Dietary intake of antioxidants and risk of age-related macular degeneration. JAMA. 2005 Dec 28;294(24):3101-7

⁹ Progression of age-related macular degeneration: association with dietary fat, transunsaturated fat, nuts, and fish intake. Arch Ophthalmol. 2003 Dec;121(12):1728-37

¹⁰ Bazan NG. Cell survival matters: docosahexaenoic acid signaling, neuroprotection and photoreceptors. Trends in Neuroscience. In Press, Corrected Proof, Available online 3 April 2006

¹¹ Chiu CJ. Dietary carbohydrate intake and glycemic index in relation to cortical and nuclear lens opacities in the Age-Related Eye Disease Study. Am. J. Clinical Nutrition, May 2006; 83: 1177 – 1184

¹² Sorenson LB. Effect of sucrose on inflammatory markers in overweight humans.
Am J Clin Nutr. 2005 Aug;82(2):421-7

¹³ www.lowglycemicdiet.com

¹⁴ AREDS Research Group. The age-related eye disease study (AREDS) system for classifying cataracts from photographs: AREDS report no. 4. Am J Ophthalmol 2001; 131(2): 167-175