Quick caffeine fix, long-term AMD risk? This study serves up new grounds for concern.
A splash of convenience may come with a shot of concern. New research published in Food Science and Nutrition suggests that drinking instant coffee could significantly raise the risk of developing dry age-related macular degeneration (AMD).
The study, led by Qi Jia and colleagues, used genetic correlations and Mendelian randomization analyses to explore whether different types of coffee have a causal link to AMD.1
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A closer look at the results
Jia et al. found that each standard deviation increase in instant coffee consumption was associated with nearly a seven-fold increased risk of dry AMD. This association held strong even after sensitivity analyses and statistical adjustments.1
“Instant coffee may increase the risk of AMD, and reducing instant coffee intake could help prevent dry AMD,” the authors concluded in their report.
Not to worry, though, fellow java friends: No significant link was observed between AMD and other coffee types, including regular brewed, ground or decaf versions.1
How the data dripped
To explore the genetic ties between coffee habits and eye health, the researchers pulled from large-scale genome-wide association studies (GWAS) through the FinnGen consortium. The team analyzed data from more than 180,000 participants on instant coffee consumption, alongside 7,589 dry AMD cases and 298,486 controls.1
Their multi-pronged approach included:
- Linkage disequilibrium score regression (LDSC) to assess genetic correlation
- Mendelian randomization (MR) to explore causal associations
- Bayesian colocalization to identify shared genetic loci1
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What this means for eye care professionals
These findings stand in contrast to earlier observational studies that hinted coffee might actually protect against AMD. According to Jia et al., those earlier results may have been skewed by confounding factors, and importantly, most didn’t differentiate between coffee types.1,2
So what’s in the instant mix that could be problematic? The study points to potentially harmful byproducts from processing, such as acrylamide and advanced glycation end products (AGEs). These compounds are known to trigger oxidative stress and inflammation in retinal cells.1
For eye care providers, this research offers new grounds (pun intended) for advising patients, particularly those at higher risk for AMD, to reconsider their instant coffee habit. The authors call for more studies to isolate the specific culprits in instant coffee and better understand how they may contribute to macular degeneration.1
READ MORE: Eyeing the Future of AMD at APAO 2025
Until then, it might be time to tell your patients to upgrade their coffee game…or at least read the label before they stir.
Editor’s Note: This content is intended exclusively for healthcare professionals. It is not intended for the general public. Products or therapies discussed may not be registered or approved in all jurisdictions, including Singapore.
References
- Jia Q, Zha Z, Li S, et al. Genetic Correlation and Mendelian Randomization Analyses Support Causal Relationships Between Instant Coffee and Age-Related Macular Degeneration. Food Sci Nutr. 2025;13(6):e70439.
- Chiu CJ, Chang ML, Li T, et al. Visualization of Dietary Patterns and Their Associations With Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci. 2017;58(3):1404-1410.
