Genetic Study Links Instant Coffee Consumption to Eye Health Risks

In a groundbreaking study published in the journal *Food Science & Nutrition*, researchers have established a significant genetic link between the consumption of instant coffee and an increased risk of developing dry age-related macular degeneration (AMD). Conducted with a sample size exceeding 500,000 individuals, the study utilized advanced genomic techniques, including Mendelian randomization analyses, to examine the correlations between coffee types and AMD risk.

The research, led by Dr. Qian Jia from the University of Helsinki, revealed that an additional cup of instant coffee daily could elevate the risk of dry AMD by as much as 7.92 times, according to the study's findings (Jia et al., 2025). This alarming statistic underscores the potential health implications of dietary choices, particularly in an aging population where AMD is already a leading cause of vision loss, affecting approximately 196 million people worldwide as of 2020, with projections suggesting a rise to around 240 million cases by 2040.

The study's results indicate a stark distinction between instant coffee and other coffee forms. Ground and decaffeinated coffee did not exhibit similar associations with dry AMD, marking instant coffee as uniquely implicated in this ocular health risk. This specificity calls into question the processing methods associated with instant coffee, which may introduce harmful compounds such as advanced glycation end products (AGEs) that could trigger retinal inflammation and oxidative stress.

Dr. Sarah Johnson, a prominent ophthalmologist at the Mayo Clinic, emphasizes the importance of these findings: "Understanding the specific impacts of different coffee types on eye health is crucial, especially for individuals predisposed to AMD. This study highlights the need for more granular research on dietary risks associated with eye diseases."

The implications of this research are significant, particularly for public health policymakers and clinicians advising patients on dietary habits that may influence AMD progression. While AMD is irreversible, prevention strategies focusing on modifiable risk factors are essential. As Dr. Liu Shen, an epidemiologist at the World Health Organization, notes, "Incorporating these findings into dietary recommendations could potentially alter the trajectory of AMD in vulnerable populations."

The methodology employed in this study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology using Mendelian Randomization (STROBE-MR) guidelines, ensuring robust and reliable results. The researchers analyzed data from the UK Biobank, including detailed statistics on coffee consumption and AMD incidence, to draw their conclusions.

Despite the compelling evidence presented, the study also highlights the limitations inherent in the genetic analysis, primarily due to its predominantly European cohort, which may limit the applicability of the findings across diverse populations. Furthermore, the genetic correlation observed does not imply direct causation, as additional research is warranted to explore other possible confounding factors.

In conclusion, this study not only sheds light on the potential health risks associated with instant coffee consumption but also calls for a broader discussion within the medical community regarding dietary advice related to eye health. As dietary patterns shift globally, maintaining awareness of how such choices impact long-term health outcomes remains imperative.

**References**: Jia, Q., Zha, Z., Li, S., Zhang, Y., Ke, L., & Liu, S. (2025). Genetic Correlation and Mendelian Randomization Analyses Support Causal Relationships Between Instant Coffee and Age-Related Macular Degeneration. *Food Science & Nutrition*, 13(6), DOI: 10.1002/fsn3.70439.