Thread by @NickAnderegg

My thoughts on this new finding? AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

"The consumption of BW [bottled water] is associated with heightened risk for certain health conditions," such as:
- hypertension (+5% increased risk)
- diabetes (+9%)
- GI ulcers (+21%)
- kidney stones (+17%)

1/10

This was a very large cross-sectional study that looked at a national population, conducted by Italy's census agency. They controlled for covariates including socioeconomic status, age, and gender, then clustered and stratified the population as appropriate.

Solid methods!

2/10

Analysis is *conceptually* straightforward:

- They built models to understand how bottled water + EACH confounding variable interacts to impact health outcomes.
- They combined those models into one big model to analyze all the variables together for each possible outcome.

3/10

In this sample, slightly over half of the population usually drank bottled water. Bottled water consumption was also associated with lower socioeconomic status (less education, less economic resources), showing that this is yet ANOTHER issue where wealth=health.

4/

For all four of the examined health outcomes, individuals with any one of those conditions (diabetes, ulcers, kidney stones, hypertension) were more likely than not to regularly consume bottled water.

Moreover, although the difference wasn't significant for hypertension...

5/

The prevalence of bottled water consumption was higher among individuals with these chronic conditions than among individuals without these chronic conditions—even after controlling for sex, age, economic resources, education, BMI, smoking, alcohol, and physical activity.

6/

Here's how you interpret the stats (using ulcers stats):

- The higher prevelance of BW drinkers among those with ulcers is statistically significant (unlikely to be due to random variation).
- BW drinkers are 21% more likely to have ulcers than someone who doesn't drink BW.

7/

What's it mean? First, note that these results don't show a *causal* link, only a *strong association* between habitual BW consumption and these chronic conditions.

Not *causal* = Maybe people with these conditions consume BW because of their condition, or simply prefer BW!

8/

Importantly, these results generally line up with what we would expect to see, however, based on previous research. Micro- and nanoplastics have been found to cause all kinds of issues with biological tissues in vitro!

9/10

Bottled water "has been found to be a possible major source of exposure" to microplastics. "Policymakers and public health institutions can no longer delay initiatives aimed at reducing plastic production, consumption, and use..."

Original paper:

10/10 mdpi.com/1660-4601/21/8…

This study just used a dichotomized (binary) variable, meaning a simple yes/no whether or not someone says they regularly drink bottled water.

However, that's perfectly adequate for logistic regression models!

11/10

I'm genuinely baffled how this is unclear, but this study is in reference to water in disposable plastic bottles.

If something is unclear, I provide the source for clarity! But I also refer to microplastics in the thread, so like... I can't *read* for you!

12/10

I welcome questions and criticisms!

I only take issue with ONE thing: A reply to the first tweet in a thread which asks a question that I made sure to address within the thread (or which is *also* addressed in the screenshot in the first tweet).

Just read the damn thing!

13/10

Some of these replies are absolutely baffling. Holy fuck.

I can't read things for you!

14/10

While I don't know how the specifics of this paper would apply to that situation, it's just generally true that reusable water bottles are better constructed than disposable plastic bottles. Durability is a factor in microplastic concentrations

15/10

As with anything, the dose makes the poison. If your organs are exposed to toxins only occasionally, they're more likely to be able to clear out the contaminants and repair any damage than if they were exposed constantly.

16/10

At the very least, it probably hasn't *helped*, considering the known impacts certain plastics can have on renal function.

However, it's also worth noting mild COVID can have serious long-term impacts on the kidneys as well:

17/10
pandemicpatients.org/home/covid-19-…

Reusable plastics are definitely at the *least concerning* end of the spectrum. A very large portion of the microplastics in a container come from mechanical abrasion (i.e. the friction of the contents), and hard plastics are more resistant to this type of wear!

18/10

All else being equal, I’d expect the total plastic particle content of bottled water to be something like

Smart Water [least] < Aquafina (when it’s in the same bottles as Pepsi) < All the super cheap plastic bottles that most bottled water comes in [most]

19/10

Other beverages in plastic containers will likely also contain some level of microplastics, but to a lesser extent if the bottle is better constructed. At the bare minimum, I’m going to avoid bottled water that comes in super cheap bottles with no structural integrity!

20/10