An Association: Macular Degeneration & Instant Coffee
- Christine Daecher, DO
- Jul 2
- 5 min read
Updated: Jul 9
When I first saw the headlines about yet another disease risk reported from an observational study, I was skeptical. But after reading more, I realized this might be one study worth paying attention to.
A recent study found that people who drink instant coffee have nearly a sevenfold higher risk of developing dry age-related macular degeneration—a strikingly strong association.
Why should we care? According to the CDC, macular degeneration is the leading cause of irreversible vision loss in the United States.1
Learn more about what macular degeneration is and the factors that increase your risk of developing it.
What is Age-related Macular Degeneration (AMD)
Macular degeneration, also called age-related macular degeneration (AMD), is a condition in which central vision gradually deteriorates and may eventually be lost. There are two forms of AMD: dry and wet.
In most cases, AMD starts as dry AMD, which develops due to gradual thinning of the macula and the buildup of a waste product called drusen (yellow deposits). The onset is usually subtle, and people may notice that straight lines appear wavy, vision becomes dimmer in low light, and it becomes harder to see at night. Other common symptoms include new difficulty with reading, delayed adjustment to indoor lighting after being outdoors, blind spots in central vision (the area you focus on), and trouble recognizing faces. Some may also find it harder to judge whether objects are level, like hanging pictures or window blinds.
Dry AMD is irreversible and will be the focus of this discussion. It is also called nonexudative AMD.
By contrast, wet AMD accounts for about 10% of cases but is more severe. It is caused by abnormal blood vessels growing under the retina, which can leak fluid and lead to relatively sudden vision loss. Wet AMD typically progresses quickly, over months, whereas dry AMD usually advances slowly over many years or even decades.
Current Recognized Risk Factors of Dry AMD
There are several known risk factors associated with the development of degenerative changes to the macula. Aging is one of them. A 2019 study found that by the age of 40 years, approximately 12.6% of the population has macular changes such as drusen deposits.2 At age 40, nearly all persons with drusen deposits do not experience vision loss. As a person ages, by the age of 85 and older, 46.6% of people have macular changes.2 Changes that occur with aging include increased drusen deposits, atrophy of the retina, and central retinal degeneration.
When it comes to dry AMD, genetics is the key rist factor, as it is considered a genetic disease. Three different research groups confirmed a major genetic locus (genetic variant) associated with an increased risk of AMD in 2005: the CFH gene and specifically, its Y402H variant. The CFH variant increases the risk of AMD by 2-7 fold when one copy of the gene is present. In the next 1-2 years, another major variant was found, ARMS2. The ARMS2 variant increases the risk of AMD by 2-3 fold when one copy of the gene is present. When a person carries two copies of either of these genes or both, their risk for developing AMD is even higher.
Some commercial genetic tests, such as 23andMe, include analysis for the CFH and ARMS2 genes. The results will indicate whether you have heterozygosity (one normal and one risk variant) or homozygosity (two copies of the risk variant).
If you have a parent, grandparent, or sibling diagnosed with dry AMD and choose not to undergo genetic testing, it is reasonable to consider yourself at increased risk based on family history alone.
Nutritional deficiencies in certain nutrients can further increase the risk of progression of dry AMD in people who already have a genetic predisposition. A good preventive strategy is to take PreserVision AREDS 2, which is supported by research from the National Eye Institute.3
What is going on with Instant Coffee?
Regarding the association with instant coffee, it is specifically dry AMD (age-related macular degeneration) for which risk was found to be increased. Importantly, the study did not find any increased risk associated with other types of coffee consumption, such as ground, filtered, or decaffeinated coffee.
The likely suspect behind this association is acrylamide, a chemical that forms during the production of instant coffee. Instant coffee production involves high-temperature processing, which leads to acrylamide formation. In the human diet, acrylamide is mostly found in plant-based foods that are baked, fried, roasted, or air-fried—such as potatoes, cereals, popcorn, and all types of baked goods—as well as coffee.4
Acrylamide forms as part of the Maillard reaction (also called the browning reaction), which is what gives these foods their appealing roasted and toasted flavors. Despite this desirable flavor, acrylamide itself is considered a waste product and has concerning biological effects. It was classified as a probable human carcinogen in 1994. By 2002, it was also recognized as genotoxic, neurotoxic, and mitochondrial toxic. In humans, acrylamide exposure can cause degeneration of both the central and peripheral nervous systems.
To understand the strength of this risk, scientific papers usually report it as a relative risk (RR), odds ratio (OR), or hazard ratio (HR). In the recent study out of China, the risk was reported as 6.92—meaning a 6.92-fold increase in dry AMD among those who drink instant coffee.5 For context, a relative risk of 1.5 or higher is often regarded as noteworthy or significant in epidemiological studies.
To put this in further perspective:
The risk of getting lung cancer among current smokers is about 20- to 40-fold higher compared to never-smokers, depending on smoking intensity.
In former smokers, the risk remains about 5- to 10-fold higher.
For individuals who already carry genetic risk variants (such as in the CFH or ARMS2 genes), this additional risk from instant coffee may compound their overall risk of developing AMD.
The key takeaway from the study is that people who are genetically predisposed to AMD should avoid drinking instant coffee. And considering the known toxicity of acrylamide, it may be prudent for everyone to limit or avoid instant coffee altogether.
References:
Ruia S, Kaufman EJ. Macular Degeneration. 2023 Jul 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan–. PMID: 32809613.
Koszucka A, Nowak A, Nowak I, Motyl I. Acrylamide in human diet, its metabolism, toxicity, inactivation and the associated European Union legal regulations in food industry. Crit Rev Food Sci Nutr. 2020;60(10):1677-1692. doi: 10.1080/10408398.2019.1588222. Epub 2019 Mar 25. PMID: 30907623.
Jia Q, Zha Z, Li S, Zhang Y, Ke L, Liu S. Genetic Correlation and Mendelian Randomization Analyses Support Causal Relationships Between Instant Coffee and Age-Related Macular Degeneration. Food Sci Nutr. 2025 Jun 14;13(6):e70439. doi: 10.1002/fsn3.70439. PMID: 40521080; PMCID: PMC12166192.
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