The Potential Role of Dietary Antioxidant Capacity on Age-Related Macular Degeneration

Summary

Including eye health, nutrition plays a vital role for the sustainability of individuals health life. There is an increasing global concern about the issues related with eye health. In 2010, in order to take attention to these issues, World Health Organization (WHO) defined the main reasons of vision disorders as refraction defects of eye diseases (43 %), cataract (33 %), glaucoma (2 %), age-related macular degeneration (AMD) (1 %), diabetic retinopathy (1 %) and undetermined natural reasons (18 %). This report also stated the three biggest reasons of blindness as cataract (51 %), glaucoma (8 %) and AMD (5 %).

AMD is a multi-factorial disease in which the genetic predisposition plays important role with environmental factors and metabolic conditions, except for age. Especially cigarette is the secondary important risk factor for dry-type AMD. In the Age Related Eye Disease Study (AREDS), it was stated that AMD prevalence is higher in white races, compared with races which are not white. At the same time, AREDS searched the effect of diet supplements on the progression of AMD disease. In terms of the patients followed for six years, it was reported that the formulation C and E vitamins, beta carotene and zinc decreased the progression risk of AMD from middle levels to advanced levels by 34 %. In AREDS-2 study completed in 2012, it was shown that the extraction of beta carotene from the formulation and the decrease of zinc did not affect the progression rate of the disease. In the group using beta carotene, including persons who were used to smoke but gave up at least one year ago, the rate of becoming lung cancer was observed as substantially high. Moreover, the use of lutein and zeaxanthin instead of beta carotene in the formula did not increase the risk of lung cancer. In addition, it was shown that omega-3 fatty acids did not decrease risk progression.

In current data, the effect of the intake of carotenoid and antioxidant increased with diet on AMD is not coherent. Likewise, the epidemiological evidences about the relation between diet fat intake and AMD are contradictory. The consumption of fatty fish is related with increased poly-unsaturated fatty acid intake and decreases the risk of AMD. However, it was reported the high rate of total fat intake in other studies as risk factor for AMD. In another study, there was not any important relation found between diet fat intake and AMD occurrence after the correction of other variables. In the interventional AREDS-2 study, it was reported that the additional intake of long-chain omega-3 poly-unsaturated fatty acids did not have any beneficial effect.

The pathophysiological mechanism responsible from the possible relation between obesity and AMD is not clearly known. There are various hypotheses about how obesity causes AMD. In the first hypothesis, obesity can cause AMD after obesity increases systematic oxidative stress. In the second hypothesis, obesity can play a role in AMD pathophysiology as the cause of hyperleptinemia. The studies also prescribed that inflammation could play a role in the progression of AMD and also showed that plasma fibrinogen and other inflammation indicators could be related with late AMD. In Pathologies Oculaires Liées à l'Age (POLA) study made with the participation of many Europeans, it was observed that the progression of late AMD increased by two times in obese individuals and in early AMD, obesity did not affect the progression of disease. In the treatment of this disease which have age-related progression, proper nutrition, vitamin/mineral/supplement usage and the development of precautionary strategies play an important role.

When compared with Body Mass Index (BMI), it was found that the measure of abdominal obesity (waist/hip rate and waist circumference) was the better determinant of chronic diseases such as diabetics and cardiovascular disease. Some evidences in the United States of America indicated that the relation between waist/hip rate and AMD gave stronger results when compared with the relation between BMI and AMD. For middle age cohort, after six years of follow-up, a group of researchers reported that the decrease of waist/hip rate also decreased the risk of AMD and the results were the same for waist circumference, even if the evidences were weak. In another study, it was reported that the increase of waist/hip rate or waist circumference also increased the progression of AMD.

This study was planned with the aim of determining the occurrence of AMD by evaluating dietary total antioxidant capacity, diet components and some anthropometric measures of individuals having age related macular degeneration (AMD). In the study, the possible effect of nutrition on the occurrence of disease was evaluated by comparing healthy individuals with dietary total antioxidant capacity and some anthropometric measures of individuals with AMD.

Conditions

• Age Related Macular Degeneration

Sponsors & Collaborators

• Hacettepe University

  lead OTHER

Principal Investigators

• F.Gülhan Samur, Ass. Prof. · Hacettepe University

• Sibel Kadayıfçılar, Prof. · Hacettepe University

• Sedat Arslan, RA · Hacettepe University

Eligibility

Min Age

50 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2015-07-01

Primary Completion

2015-10-01

Completion

2016-02-20

Countries

• Turkey (Türkiye)

Study Locations