A greater understanding of the mechanics of age-related macular degeneration is our key to helping those with the disease, and even preventing its development. One area which shows promise is the effect of the Mediterranean diet.
We already know this diet can reduce the risk of heart disease and type 2 diabetes but over the last 10 years more research has shown how it also benefits the eyes. The reason it appears to be so beneficial because it is made up of a combination of nutrient rich foods, like olive oil (monounsaturated fats), nuts and fish (omega-3 fatty acids), vegetables, fruit and whole grains.
We’ve collated one recently published study and two older studies which all look at adherence to the Mediterranean diet and development of AMD. We’ve summarised the significance of this link, and which parts of the diet could be particularly beneficial.
AREDS study
One of the largest clinical trials funded by the National Eye Institute, the AREDS (age-related eye disease study) studied the eye health of 2500 participants over 13 years, with diet being observed as part of the research.
1028 patients in the study progressed to having advanced AMD. The researchers found a higher adherence to the Mediterranean diet reduced risk of progression to the advanced stage. They measured this using an alternate Mediterranean diet (aMeDi) score with a range of 0-9; the score was constructed using individual intakes of the following:
- Vegetables
- Fruit
- Legumes
- Whole grains
- Nuts
- Fish
- Red and processed meats
- Alcohol
- Ratio of monounsaturated to saturated facts
A high aMeDi score (6-9) was ‘significantly’ associated with a reduced risk of progression to advanced AMD, after demographic, behavioural, ocular and genetic covariates. This shows that the combination of the diet is what benefits the person. The study also shows that reducing intake of red meat, processed meat and saturated fats could be beneficial.
Blue Mountains Eye Study
The Blue Mountains Eye Study undertaken by the University Of Sydney found that omega-3 fatty acids could help to prevent age-related macular degeneration. This long-term study began studying patients 1992; the 2454 people recruited were studied over a 10 year period. Each participant completed a food frequency questionnaire which was analysed to review their intake of fatty acids.
After adjustments for age, gender and smoking, it was found that eating one portion of fish per week was associated with a 31% lower risk of developing AMD. Further to that, eating one to two servings per week of nuts was associated with a 35% lower risk of AMD.
“In conclusion, our findings support the hypothesis that increased intake of omega-three polyunsaturated fatty acids and regular consumption of fish and/or nuts in the diet may protect against the development of early AMD. These fatty acids may protect the eyes by preventing the build-up of plaque in the arteries or reducing inflammation, blood vessel formation and oxygen-related cell damage in the retina.”
Jennifer S.L. Tan, M.B.B.S., B.E., of Westmead Hospital, University of Sydney, Australia
University of Coimbra study
The most recently published study in to the link was presented at AAO 2016 by researchers from the University of Coimbra in Portugal. They studied 883 people over the age of 55 from 2013 to 2015; 449 had early stage AMD and 434 did not have AMD.
Their diets were assessed using a questionnaire asking how often they ate foods associated with the Mediterranean diet. Using the same 0-9 scoring as the AREDS study they found:
- Higher scores meant lower AMD risk. Of those who didn’t closely follow the Mediterranean diet, 50% had AMD. Of those who did closely follow the diet, 39% had AMD, representing a 35% lower risk of AMD compared with those who did not follow the diet closely.
- Fruit was found to be beneficial, of those who consumed 150 grams (5oz) of fruit per day 54% did not have AMD and 45% had AMD. A 15% lower risk of AMD.
- Caffeine and other antioxidants were shown to be protective to the eyes as well. Those who consumed higher levels of caffeine, (78mg a day or a single shot of espresso), 54% did not have AMD, and 45% had AMD.
In conclusion, closely following the Mediterranean diet seems to offer the eyes some protection against AMD. This can be explained by the increased intake of omega-3 fatty acids and additional antioxidants from fruit and caffeine, but could also be from the combination of foods in the diet.
More research is still being undertaken in to the link between the diet and eye health, but in the meantime it is a beneficial diet to recommend to a patient for their overall wellbeing. The fact that it could be helpful in the fight against AMD is promising, especially with more people being diagnosed each year.
Find the research resources below, or read more about AMD in our free whitepaper.
Resources
https://www.aao.org/newsroom/news-releases/detail/fruit-rich-mediterranean-diet-with-antioxidants