Study Links Instant Coffee Consumption to Age-Related Vision Loss

A recent study conducted by researchers at Hubei University of Medicine in China has established a concerning link between the consumption of instant coffee and an increased risk of age-related macular degeneration (AMD), particularly its dry form. The study, which analyzed genetic data from over 500,000 individuals, suggests that those predisposed to AMD may benefit from switching to ground coffee in an effort to protect their eyesight.

The findings were published in the journal Food Science and Nutrition on June 22, 2025. The lead researcher, Siwei Liu, who is affiliated with the Department of Ophthalmology at Shiyan Taihe Hospital, noted that their research revealed a genetic correlation between instant coffee consumption and dry AMD. "Our results indicate a significant overlap between the genetic predisposition for instant coffee intake and the risk of developing dry AMD," Liu stated, highlighting the potential shared genetic markers that influence both traits.

AMD is a chronic eye disease that primarily affects older adults, gradually damaging the macula—the central part of the retina that is essential for sharp vision. According to the National Eye Institute, AMD is one of the leading causes of irreversible blindness globally, impacting nearly 200 million people, with projections suggesting this number could rise to 290 million by 2040. The disease manifests in two forms: dry and wet. Most individuals suffer from dry AMD, which involves a thinning of the macula, while wet AMD, characterized by abnormal blood vessel growth in the eye, is less common but causes more rapid vision loss.

The researchers utilized data from the UK Biobank, which provided comprehensive information regarding participants' coffee consumption habits, including distinctions between instant, ground, and decaffeinated varieties, as well as health data related to AMD diagnoses. This extensive dataset enabled the researchers to draw statistically significant correlations between instant coffee consumption and an increased risk of developing dry AMD. The study attributed certain harmful byproducts and additives, such as acrylamide and oxidized lipids found in instant coffee, as contributing factors to the disease.

While instant coffee remains popular due to its convenience, the emerging research raises critical questions about its long-term health implications. Dr. Emily Carter, an ophthalmologist at Johns Hopkins University, emphasized the need for further research. "This study adds to the growing body of evidence suggesting that dietary factors can play a significant role in the development of ocular diseases. However, more longitudinal studies are needed to establish direct causation and fully understand the mechanisms involved," she stated.

Conversely, Dr. Alan Smith, a nutritionist and coffee industry expert, argues that the study's findings should not lead to alarmist conclusions. "While the results are noteworthy, they should be viewed in the context of an individual's overall diet and lifestyle. Coffee consumption, whether instant or ground, is just one aspect of a much larger picture when it comes to health and wellness," he remarked.

The implications of these findings are significant, especially for individuals over the age of 50 or those with a family history of AMD. Health professionals are likely to advise such individuals to reconsider their coffee consumption habits. Switching to ground coffee may offer a simple, preventive measure against a condition that profoundly affects quality of life.

As the research community continues to explore the relationship between diet and eye health, this study serves as a reminder of the importance of informed dietary choices. The results not only underscore the potential risks associated with instant coffee but also contribute to a broader conversation about nutrition and its impact on long-term health outcomes. Future research will be critical in confirming these findings and guiding public health recommendations regarding coffee consumption.