Can PET microplastics from plastic bottles affect metabolism?
Yes in animal research. A 2026 rat study found that one oral dose of PET microplastics caused mild metabolic and gut changes, with effects varying by dose and sex.
What's actually in it
PET is the clear plastic used in many water and soda bottles. PET can break into tiny particles called microplastics.
Plastic bottles are not the only PET source. PET is also used in some clothing and other consumer products.
What the research says
A 2026 study in Drug and Chemical Toxicology gave rats one oral dose of PET microplastics. The researchers measured metabolism, blood markers, and gut and liver gene activity for about 18 hours.
The study found mild metabolic and gastrointestinal disruption. Effects varied by sex and dose. For example, some male rats had lower metabolic rate, respiratory exchange ratio, and blood insulin after the low dose. Some female rats had lower metabolic rate at the high dose and higher LDL with dose.
This was an animal study. It does not prove the same effect in people after one bottle of water. It does support reducing repeat exposure to PET microplastics where simple swaps exist.
What to do
Do not heat plastic water bottles. Do not reuse single-use bottles for months. For daily water, choose stainless steel kitchen swaps.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| A single oral exposure to polyethylene terephthalate microplastics causes mild metabolic and gastrointestinal disruption: dose and sex determinants. | Drug Chem Toxicol | 2026 |