Hello from Greycoat Research,
When caring for a cat with kidney disease,
most guardians pay close attention to food, supplements, and subcutaneous fluids.
But surprisingly, water itself is often overlooked.
One common example is bottled water.
Recent studies have shown that bottled water can contain both microplastics and nanoplastics.
A 2024 study found a surprisingly large number of micro- and nanoplastic particles in bottled water.
NIH summary:
https://www.nih.gov/news-events/nih-research-matters/plastic-particles-bottled-water
PNAS study:
https://pubmed.ncbi.nlm.nih.gov/38190543/
So what does this mean for kidney health?
At this stage, we cannot say that bottled water directly worsens kidney disease in humans or cats.
However, studies do suggest that microplastics may affect kidney cells and kidney tissue.
For example:
-
A 2023 review on kidney-related research concluded that microplastics were associated with oxidative stress, inflammation, autophagy, and cellular damage in animal models and kidney cell studies.
Review article: https://pubmed.ncbi.nlm.nih.gov/37762695/ -
A 2021 study reported that long-term exposure to polystyrene microplastics led to accumulation in kidney cells and mouse kidney tissue, along with mitochondrial dysfunction, ER stress, inflammation, and autophagy.
Study: https://pubmed.ncbi.nlm.nih.gov/33956507/ -
In a human kidney cell study, microplastic exposure was associated with reduced cell proliferation and increased ROS levels.
Cell study: https://pmc.ncbi.nlm.nih.gov/articles/PMC9520709/
In other words, the evidence is not yet conclusive.
But if a cat already has weakened kidneys,
there is little reason to add more avoidable exposure.
Cats with kidney disease already have a harder time managing waste and maintaining fluid balance.
For that reason, it may be wise to take a more cautious view not only of food and supplements,
but also of the water they drink and the environment they are exposed to every day.
That is why Greycoat takes this position:
We are not saying that bottled water is absolutely dangerous.
But for cats with kidney disease,
choosing a simpler and more stable water environment may be a more cautious choice.
For example:
- Use glass or stainless steel water bowls instead of plastic bowls
- Avoid leaving water in hot environments, such as inside a car or near heat
- When possible, reduce how often plastic is used to store water
- The goal is not fear, but reducing repeated exposure over time
Kidney care is rarely shaped by one major intervention alone.
More often, it is influenced by small daily choices that add up over time.
Greycoat will continue to share grounded, evidence-based information
to help guardians make more careful decisions for their cats.
For the small daily choices that support kidney health,
Greycoat is here to support you.
Sincerely,
Greycoat Research
