A new study published in Food Science & Nutrition has found a striking link between instant coffee consumption and a significantly increased risk of developing dry age-related macular degeneration (AMD)—a common eye condition that affects central vision.

Age-related macular degeneration impacts an estimated 200 million people globally. It typically affects individuals over the age of 50 and leads to gradual vision loss, particularly in the central field of sight. There are two primary forms of the condition: dry AMD, which involves slow deterioration of the macula (the central part of the retina), and wet AMD, which results from abnormal blood vessel growth behind the retina, causing more rapid and severe damage.

In the study, researchers analyzed coffee consumption habits of over 500,000 people using data from the UK Biobank, categorizing participants by their preferred coffee type—decaffeinated, ground, or instant. They then cross-referenced this information with data on AMD incidence in individuals over 50 from the Finnish Finngen genome-wide association study (GWAS) dataset.

Using advanced genetic analysis methods such as Mendelian randomisation and linkage disequilibrium score regression (LDSC), the researchers explored potential hereditary connections between coffee consumption and AMD risk.

Their findings revealed a noteworthy genetic correlation: individuals genetically predisposed to drinking instant coffee were also more likely to develop dry AMD. Specifically, the study suggests that instant coffee drinkers may face up to a sevenfold increase in the risk of developing the condition, compared to those who prefer other types of coffee.

While the study highlights a potential risk factor, researchers caution that more investigation is needed to understand the biological mechanisms behind this connection and whether other lifestyle or environmental factors may also play a role.