Headlines keep asking whether plastics make us age faster. At the same time, biological age tests promise to tell you how fast your body is ageing. So it is fair to wonder: could a test show what plastics are doing to you?

The short answer is not yet. To see why, it helps to ask three questions. Are we talking about particles or chemicals? What have researchers actually measured? And what does that let you conclude about yourself?

1. Particles or chemicals?

"Plastics" covers two different things, and the research on each is separate.

Particles. Microplastics are pieces of plastic smaller than 5 mm, and nanoplastics are far smaller still. They come from bottles, packaging, clothing fibres, tyres and much more.

Chemicals. Plastics also contain added chemicals. Phthalates are added to some plastics, such as soft vinyl, to make them flexible, and they are also used in many personal-care products such as perfumes and lotions. Bisphenols, such as BPA and its substitute BPS, are used in some plastic bottles and can linings.

This matters because some harm blamed on "plastics" may come from the chemicals in them rather than the particles, and research rarely separates the two. As you will see, the chemicals have been studied against biological age scores. The particles mostly have not.

2. What have researchers measured?

Plastic chemicals and biological age

Biological age is an estimate of how old your body seems, as opposed to your age in years. Some versions are calculated from routine blood tests. Others, called epigenetic clocks, are read from chemical tags on your DNA. (More on how these tests work.)

Phthalates. Several analyses of overlapping data from one large US health survey found that adults with higher levels of most phthalates in a single urine sample had, on average, slightly older biological-age scores calculated from routine blood tests. Not every phthalate pointed the same way. The differences were small: a few tenths of a year per step up in a combined exposure score (Xiao et al., 2023).

Two caveats matter. These are associations, not cause and effect: exposure and age score were measured at the same time, from one urine sample. And phthalates leave the body within hours, so one urine sample is only a snapshot of recent exposure. For some phthalates, such as DEHP from food, levels can swing a lot from one sample to the next in the same person, which makes single-sample studies imprecise (Preau et al., 2010).

For epigenetic clocks, the evidence is thin and mixed. In one US dataset, one phthalate was linked to older readings on several clocks, but that analysis did not correct for testing many combinations. A larger, stricter analysis of the same survey found only weak hints (Khodasevich et al., 2025). A Taiwanese study even found one phthalate linked to a younger clock reading.

Bisphenols. In a Canadian study of 224 mother–baby pairs, higher BPA in the mother's urine in mid-pregnancy went with a slightly higher reading on a children's epigenetic clock at about three months: less than a week per doubling of BPA, clearest in girls (England-Mason et al., 2024). In babies, though, a higher clock reading does not simply mean faster ageing; its meaning is still debated. We found no study testing bisphenols against epigenetic clocks in adults; a 2025 review of 102 chemical-exposure clock studies included none (Fadadu et al., 2025).

So far, no reliable human evidence shows that bisphenols make people age faster. The early signals justify more research.

Plastic particles in the body

Researchers have reported plastic-like particles in human tissue and fluids, including artery plaque, blood clots, bile, placenta, stool, lung and liver. These are small detection studies, the amounts they report are debated, and finding a particle tells you nothing about what it does.

Part of the debate is technical. Measuring plastic inside the body is hard: the main lab method can mistake natural fats for polyethylene, so some reported amounts may be too high (Rauert et al., 2025).

One widely reported human finding comes from Italy. 257 people had plaque removed from a narrowed neck artery. Those whose plaque tested positive for plastic (almost all of it polyethylene) had more heart attacks, strokes and deaths over the next three years or so (Marfella et al., 2024). It is one study, in people already having major artery surgery. It cannot show cause and effect, the authors could not rule out lab contamination, and polyethylene is the polymer hardest to measure reliably in human tissue.

Plastic particles in the lab

In lab cells and animals, plastic particles can trigger ageing-related processes: oxidative stress, mitochondrial damage, cell senescence and inflammation.

The doses are the catch. A 2026 review of 88 laboratory studies found they typically dosed animals and cells at a hundred to ten million times the levels measured in the environment, and that harm was rarely seen at realistic levels. Those studies were mostly on wildlife and lab organisms (a third of them on insects), not on people, and the same review says few studies properly test realistic exposure. It is a verdict on the research, not a clean bill of health (Zhang et al., 2026). Lab work most often uses uniform polystyrene spheres (in almost half of the studies one review counted), while people mostly meet weathered polyethylene, nylon and PVC (Wright et al., 2024).

A study we could not find

Our literature search found no study relating microplastic or nanoplastic particle exposure to an epigenetic-clock result. Research on plastic-associated chemicals is a separate evidence base, with some early, mixed findings. A few animal studies measured telomeres (the protective caps on chromosomes) instead, with mixed results; one at a realistic dose found no effect (Martin et al., 2025).

The fair summary today: plastic particles are a plausible contributor to ageing biology, not a demonstrated driver of human ageing (Moulton et al., 2026).

3. What can you conclude about yourself?

Biological age tests have not been shown to detect plastics. We know of no biological age test that has been shown to detect plastic exposure, or its effect, in an individual. Urine tests for these chemicals show only recent exposure; they do not measure ageing. Every biological age test has limits of its own, and it helps to know them before reading too much into a result (the limits of ageing clocks).

Small score differences are not a diagnosis. No study has followed people to see whether the small score differences linked to phthalates lead to more illness or a shorter life.

Lowering exposure is possible, for a while. In small, short studies where researchers supplied fresh, unpackaged food, urine levels of BPA and some phthalates fell within a few days (Rudel et al., 2011). When people only received advice, results were smaller or inconsistent. The drops were also short-lived: BPA climbed back within days of returning to the usual diet. And individual changes don't always work: in one small trial, levels of one phthalate rose sharply during a supplied "clean" diet, because some of the food was itself contaminated (Sathyanarayana et al., 2013).

Across whole populations, the picture is different. Reviews of dozens of studies found the largest and longest-lasting drops after rules limited these chemicals in products and packaging, though replacement chemicals sometimes rose (Sieck et al., 2024).

For particles in water, one lab study found that boiling hard (chalky) tap water trapped most of the tested plastic particles in limescale. Whether this lowers what ends up in the body has not been tested (Yu et al., 2024).

What no study has shown yet is that lowering exposure changes biological age or an ageing biomarker. So cutting exposure can lower some of these chemicals in your body for a while, but nobody can promise it will make you biologically younger.

The bottom line

  • Plastic chemicals: small, early, mixed links with biological age scores, mostly from a single measurement.
  • Plastic particles: reported in human tissue in uncertain amounts, and ageing-type damage in the lab, mostly at doses far above real life.
  • The key study, particle exposure against an epigenetic clock, is one our literature search did not find.
  • We know of no biological age test that can show you what plastics are doing to you.

That is less dramatic than the headlines. It is also where the science honestly stands, and a good reason to watch for the studies that will settle it.

About the author: IntrinsicAge is an independent, evidence-led guide to biological age testing. It explains how ageing clocks work, what they can and cannot tell you, and how to choose a test.