Introduction
Single-serve coffee pods have become part of daily life in homes, hotels and offices across Ireland. hey offer speed, convenience and the promise of café quality coffee at the touch of a button, for a fraction of the price of a coffee shop brew. Their convenience is undeniable. Yet beyond the convenience, there is much more to consider.
Most pods are made from several layers of materials, often including plastic, aluminium and chemical coatings designed to protect flavour and withstand high temperatures. When hot water and pressure are applied during brewing, small amounts of these substances may migrate into the coffee itself. Studies have detected traces of aluminium, microplastics and other compounds that may leach from the capsule lining. While the levels are typically low, scientists are still exploring the long-term effects of regular exposure to these materials. What appears to be a simple capsule is in fact a complex container that can influence more than just taste, it may also affect what ends up in your cup.
European research into how heat and pressure affect capsule materials reveals that coffee brewed in plastic or aluminium pods can contain trace amounts of metals or chemical compounds that are not naturally found in coffee beans. These exposures may be small in each cup, but for daily coffee drinkers, they can accumulate over time.
This article looks at what happens when aluminium or plastic meets heat and water, how those substances are absorbed by the human body, and what science says about their potential long-term effects.
Table of Contents
How Aluminium Enters the Body
What Happens Once It Is Absorbed
How Plastic Coffee Pods Affect the Body
Why This Is An Important Consideration for Long-Term Health
Choose Coffee That’s Good for You and the Planet
Frequently Asked Questions
Recommended Reading
Quick Summary
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Aluminium can leach into coffee under certain conditions during brewing and be absorbed through the gastrointestinal tract.
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Once in the bloodstream, it binds to ferritin and transferrin proteins, allowing it to cross the blood–brain barrier.
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Plastic pods can release bisphenols (BPA, BPS, BPF) and microplastics when heated.
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These chemicals can disrupt hormones, metabolism, and reproductive health.
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EU and Irish research bodies continue to investigate the cumulative effects of low-level exposure and further research is needed
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Compostable and biobased coffee pods represent a promising alternative that may reduce certain chemical risks associated with conventional plastic or aluminium pods.
How Aluminium Enters the Body
A study published by Windisch J, Keppler BK, Jirsa F. Aluminum in Coffee ACS Omega (2020) explains the process of how aluminium enters the body, aluminium is absorbed in the gastrointestinal tract, from there, it can bind to ferritin and transferrin, two proteins responsible for storing and transporting iron. Once bound to these proteins, aluminium can pass through biological barriers, including the blood–brain barrier, a protective filter designed to keep harmful substances out of brain tissue. This process allows aluminium to accumulate in organs over time. This consideration becomes even more important for individuals with kidney impairment or those with high cumulative exposure, as they may be at increased risk.
What Happens Once It Is Absorbed
Once aluminium enters circulation, it tends to accumulate in the liver, kidneys, bones, and brain. Chronic exposure has been associated with oxidative stress, cellular inflammation, and disruption of normal nerve communication.
There is growing research suggesting that aluminium is neurotoxic and may play a role in neurodegenerative processes. Several post‑mortem human studies have found higher aluminium concentrations in the brains of individuals with Alzheimer’s disease and other conditions compared with controls. Neurodegerative diseases lAlzheimer’s and Parkinson’s diseases begin in the brain and involve the progressive loss of neurons. A key feature of both diseases is the accumulation of misfolded proteins, which clump together to form toxic aggregates. These aggregates disrupt normal neuronal communication and can eventually lead to cell death.
Experimental models show that aluminium exposure can lead to oxidative stress, iron disruption, and accumulation of proteins associated with neurodegeneration. However, it is important to emphasise that current evidence does not establish aluminium as a confirmed cause of Alzheimer’s or Parkinson's disease and more research is needed.
Ferritin and transferrin are vital for red blood cell formation. When aluminium binds to them, it may trigger oxidative damage, which can weaken cell membranes and affect iron handling. This process has been linked to potential energy loss and cognitive effects over time. Because the human body cannot easily break down or eliminate these compounds, aluminium can persist for years.
How Plastic Affects the Body
Plastic coffee pods are typically made from polypropylene, a petroleum-based material valued for its heat resistance and durability. However, when hot water passes through it at high pressure, chemical compounds may leach into the beverage. These include BPA, BPS, and BPF, which are part of the bisphenol family.
Bisphenols are known endocrine disruptors, chemicals that mimic natural hormones and interfere with normal metabolic and reproductive functions.
A 2025 study published in Nature Medicine, led by toxicologist Matthew Campen from the University of New Mexico, found that microplastic concentrations in the brain were higher than in other organs and had increased significantly over time. The study noted a correlation: brains from individuals with dementia had up to 10 times more microplastics than those from individuals without the condition. Research in humans is still evolving.
Under EU law (Regulation 1935/2004 and its specific measure for plastics, Regulation 10/2011), materials intended to contact food or drink, such as the plastics and coatings used in coffee pods, must be manufactured so they do not transfer their constituents to food in quantities that could endanger health. The law sets both overall migration limits (for substances with no specific limit) and specific migration limits for known substances. At the same time, manufacturers must guarantee traceability, provide a declaration of compliance, and label the product as suitable for food‑contact use. Yet typical consumer use of coffee pods involves high heat, pressure and coffee’s acidic environment conditions that may not be fully mirrored in standard migration tests. In other words, while the legal framework is in place, the complexity of a multi‑layer pod under brewing conditions invites closer scrutiny
Comparison: Aluminium vs Plastic
| Pod Material | Main Risk | Exposure Pathway | Potential Health Impact |
|---|---|---|---|
| Aluminium | Metal leaching during brewing | Ingestion through coffee | Accumulation in brain and organs, oxidative stress, potential neurodegenerative links |
| Plastic (Polypropylene) | Chemical leaching, microplastic release | Ingestion through heated beverage | Hormonal disruption, cardiovascular and reproductive health effects |
Why This Is a Consideration for Long-Term Health
For most coffee drinkers, the issue is not a single cup, it’s years of daily exposure. Coffee is among the most consumed beverages in Ireland, and the trace amount of aluminium or plastic compounds from each brew can add up over time.
The EFSA sets a tolerable weekly intake for aluminium at 1 milligram per kilogram of body weight. A person drinking multiple coffees per day from aluminium pods could reach or exceed this threshold depending on the capsule’s integrity and design.
For plastic pods, the concern lies in chemical migration. Heating plastic accelerates the release of bisphenols. Although some brands advertise “BPA-free,” the substitutes BPS and BPF behave in much the same way. Regulators such as the European Chemicals Agency (ECHA) and the European Environment Agency recognise that certain endocrine‑disrupting chemicals may interfere with hormone systems, and there is concern that effects may occur at very low exposure levels. However, the evidence in humans remains complex and subject to ongoing scientific debate.
Microplastics are especially concerning because they do not degrade easily. Once ingested, they may settle in the gut, liver, or reproductive organs, contributing to inflammation and oxidative stress. Over time, this can impact fertility, metabolic function, and immune response.
Choose Coffee That’s Good for You and the Planet
At Fzin Coffee, we believe good coffee should never compromise health or sustainability. Our alternative to aluminium and plastic is a range of certified compostable and biobased capsules that are safe for both people and the planet.
All products are manufactured by Mokador in Italy primarily using green energy and are certified under ISO 9001 (Quality Management) and ISO 14001 (Environmental Management). These standards verify responsible production, waste reduction, and continuous improvement in environmental performance.
When you buy from Fzin Coffee, your coffee is free from aluminium and plastic exposure. Each cup supports responsible sourcing, better health, and a circular economy that keeps materials in use without harm to people or the planet.
Frequently Asked Questions
Is it safe to drink from aluminium pods occasionally?
Occasional use is unlikely to cause harm, but long-term consumption increases the risk of metal accumulation. Compostable alternatives eliminate that risk entirely.
Do BPA-free plastic pods make coffee safer?
Not necessarily. Most “BPA-free” plastics still contain BPS or BPF, which act similarly as endocrine disruptors.
Can aluminium and plastic cause Alzheimer’s?
There is no single cause. Multiple studies suggest that chronic exposure to aluminium may be linked to neurodegenerative processes. Some research also raises concerns that chemicals from plastic, such as bisphenols and microplastics, could affect brain health over time, but further study is needed.
Are compostable pods completely safe?
Certified compostable capsules are tested to ensure they do not contain aluminium or conventional plastics