In the news: Unhealthy Eating Pattern Associated with 3-Fold Higher Risk of Late AMD

Diet: One Way to Modify Risk of AMD Vision Loss?

According to the National Eye Institute, the estimated number of people with AMD is expected to more than double from 2.07 million to 5.44 million by 2050 – a projected increase that underscores an urgent need to identify risk factors for this common eye disease.

The results of a new, long-term study (1) suggest that what we consume may be one important – and modifiable – factor influencing whether AMD-related vision loss occurs later in life.

Objective and Methods

Researchers from the State University of New York, Buffalo set out to determine the association between dietary patterns and the 18-year incidence of AMD. Subjects in the current investigation were participants in the Atherosclerosis Risk in Communities or ARIC Study (a large prospective, population-based study) who showed change in AMD lesions between retinal photographs taken at visit 3 and visit 5 in ARIC.

Retinal photographs taken at visits 3 and 5 were graded side by side to determine the number of those who developed AMD out of 1,256 without AMD and 22 with early AMD at visit 3. Over a mean 18 years of follow-up, 117 participants developed early AMD and 27 developed late AMD.

ARIC participants completed dietary surveys (food frequency questionnaires) twice, at visits 3 and 5. The researchers used that dietary data to identify 29 food groups and categorize dietary patterns into two types using average food group servings.

The first of the two dietary patterns, called “Western” (unhealthy), included large amounts of processed and red meats, fried food, dessert, eggs, refined grains, high fat dairy and sugar sweetened beverages.

The other pattern, called “prudent” (healthy) was high in all vegetables (particularly cruciferous, carotene-containing and dark leafy greens), legumes (e.g. beans, peas), poultry, fresh fruits, fish and seafoods

Logistic regression was used to estimate ORs and 95% CIs for incident AMD (any, early and late) after dividing the dietary pattern scores into three groups (tertiles) adjusted for age, race, education, total calories and smoking status.

Results

While no significant associations were observed between either dietary pattern and incident ‘any’ or incident early AMD, a threefold higher incidence of late AMD was seen among participants with a Western pattern score above, as compared with below, the median (OR=3.44 (95% CI 1.33 to 8.87), p-trend= 0.014).

The risk of developing late AMD was decreased, but not statistically significant, among participants with a Prudent pattern score above vs. below the median. (OR=0.51 (95% CI 0.22 to 1.18), p-trend= 0.054).

Comments

The results of this study suggest that consuming a Western pattern diet could well be a risk factor for developing late AMD. The findings complement those from two recent prospective studies (2,3 ) which found a reduced risk of late AMD among people who ranked high vs. low on a Mediterranean (healthy) diet score.

Nutrients present in the ‘prudent’ and Mediterranean diet such as lutein, zeaxanthin and the omega-3 fatty acids EPA and DHA, are thought to promote a healthy immune system and reduce oxidative stress due to free radicals and inflammatory changes in the retina.

References

1. Dighe, S, et al. Diet patterns and the incidence of age-related macular degeneration in the Atherosclerosis Risk in Communities (ARIC) study. Br J Ophthalmol. Epub ahead of print, Dec. 6, 2019.
2. Merle BMJ, et al. Adherence to a Mediterranean diet, genetic susceptibility, and progression to advanced macular degeneration: a prospective cohort study. Am J Clin Nutr. 102:1196–206, 2015.
3. Merle BMJ, et al. Mediterranean diet and incidence of advanced ARMD: the EYE-RISK Consortium. Ophthalmol. 126:381–90, 2019.