A new study has found a striking connection between instant coffee consumption and a significantly higher risk of developing dry age-related macular degeneration (AMD), a leading cause of vision loss that affects an estimated 200 million people globally.
The research suggests that people with certain genetic traits linked to a preference for instant coffee may be nearly seven times more likely to develop this degenerative eye condition than those without the same genetic markers.
AMD is a leading cause of central vision impairment, especially among older adults in developed nations. It exists in two primary forms: dry and wet. The dry form, which makes up the majority of cases, progresses gradually and results from the deterioration of the macula, a critical region of the retina responsible for sharp, central vision. Wet AMD, while less common, tends to be more aggressive, as it involves abnormal blood vessel growth that damages the retina more quickly.
As AMD progresses, it can make once-routine tasks—like cooking, watching television, or navigating familiar spaces—challenging or even impossible. While it doesn’t cause complete blindness, it significantly compromises quality of life by stripping away the detail-oriented vision many people rely on.
While certain risk factors for AMD are out of a person’s control, such as age and genetic background, others can be influenced by lifestyle. Smoking, physical activity, body weight, and dietary choices all contribute to disease risk. Diets rich in antioxidants, such as lutein and zeaxanthin, along with zinc, vitamins C and E, and omega-3 fatty acids, have been linked to a reduced likelihood of AMD progression. However, until now, the role of specific food and beverage choices and their interactions with genetic predisposition has been less clear.
Dr. Siwei Liu, an ophthalmology researcher at Shiyan Taihe Hospital, Hubei University of Medicine in China, led the new study, which was published in the journal Food Science & Nutrition, in an effort to clarify those connections.
“AMD is a leading cause of vision loss among the elderly in developed countries. As there is currently no cure, identifying new modifiable factors is crucial for slowing disease progression, preserving vision, and improving patients’ quality of life.”
To explore this hypothesis, researchers gathered genetic and dietary data from over 500,000 individuals who had participated in the UK Biobank project, a major genome-wide association study (GWAS). Participants were grouped by their coffee consumption habits—decaffeinated, ground, or instant—and compared against AMD outcomes recorded in the Finngen GWAS dataset, which includes data from individuals aged 50 and older.
“Coffee is one of the most widely consumed beverages worldwide and is rich in polyphenols and antioxidants that may offer neuroprotective effects. At the same time, growing evidence shows that genetics influence dietary preferences. Studying the genetic predisposition to coffee consumption and its relationship with AMD risk may help reveal potential causal links between diet and eye diseases.”
The researchers employed advanced statistical methods, including Mendelian randomization and linkage disequilibrium score regression, to determine whether there was a causal relationship between coffee preference and the development of AMD.
Their analysis revealed a striking result—individuals with a genetic tendency toward drinking instant coffee were significantly more likely to develop dry AMD. This association did not appear for other types of coffee, such as ground or decaffeinated, and there was no link found between any form of coffee consumption and wet AMD.
“This genetic overlap suggests that there may be shared biological pathways or metabolic mechanisms connecting the preference for instant coffee with the risk of developing dry AMD. It provides new insight into AMD pathogenesis and offers a potential direction for personalized prevention strategies, such as gene-informed lifestyle interventions.”
Coffee, broadly speaking, is one of the most consumed beverages on the planet and is often praised for its antioxidant content and potential neuroprotective effects. But instant coffee is heavily processed, usually made by freeze-drying or spray-drying brewed coffee, which can alter its chemical composition.
The study’s authors speculate that these processing methods may play a role in the increased risk, though the precise mechanisms remain under investigation. Liu and her team plan to validate their findings in additional populations and conduct functional studies to determine whether specific compounds in instant coffee or the way the body metabolizes them might be directly involved in the onset of AMD.
Experts not involved in the study have expressed interest in the findings, though they also urge caution. Dr. David I. Geffen, an optometrist and director of refractive services at the Gordon Schanzlin New Vision Institute in La Jolla, California, told Medical News Today that while the study raises intriguing questions, more research is needed.
“With our population living longer, AMD is one of the leading disabilities in the senior population. Any change in lifestyle to minimize this risk is well worth exploring.”
“With the large increase in AMD seen in [the United States], it is important to continue with vital research in this area. The costs associated with caring and treating AMD patients [make it] worthwhile to find ways to minimize the risk associated with this disease.”
However, Geffen pointed out several areas where further information is needed. For instance, the study didn’t specify the amount of instant coffee participants were consuming, nor did it account for socioeconomic or behavioral factors that might be related to both coffee consumption habits and health outcomes.
“Is socioeconomic class associated with this? Is there some lifestyle associated with the risk in these individuals? This is way too early to make large assumptions about instant coffee drinking.”
Dr. Benjamin Bert, an ophthalmologist at MemorialCare Orange Coast Medical Center in California, also weighed in. He noted that the study represents a broader trend toward precision medicine, where care is tailored based on genetic profiles. “First, the study demonstrates one of the future directions of medicine that we have been hearing about: directing care based off of someone’s specific DNA risk profile,” Bert explained. “In this study, they found that people have a higher risk of dry AMD with certain genetic markers and consumption of instant coffee.”
Bert also highlighted another key theme of the study—the growing understanding of food as a form of medicine.
“More and more, we are realizing how our food and drink choices can impact our overall health. This study once again points to the dangers of highly processed foods, like dehydrated instant coffee, compared to its more natural form of brewed coffee, which had no added risks.”
Both experts agreed that while the findings are promising, much remains to be clarified. Future research may focus on other foods with similar processing methods to determine whether instant coffee is unique in its association with dry AMD or part of a larger trend involving processed dietary items.
For now, the results serve as a reminder that our genes and daily habits often interact in complex and sometimes surprising ways. While more studies are needed before making specific recommendations, individuals at risk for AMD, especially those with a family history, may consider small changes, such as switching from instant to brewed coffee, as a proactive step toward protecting their vision.
Moumita Basuroychowdhury is a Contributing Reporter at The National Digest. After earning an economics degree at Cornell University, she moved to NYC to pursue her MFA in creative writing. She enjoys reporting on science, business and culture news. You can reach her at moumita.b@thenationaldigest.com.
