Fluoridation: The RCT We Still Haven't Run (But Should)

post by ChristianKl · 2025-01-11T21:02:47.483Z · LW · GW · 3 comments

Contents

  The IQ Elephant Continues to Loom Large
  Salt:
  The ROI is Sky-High - A True Win-Win-Win
None
3 comments

Empiric status: My own idea written up with the help of Gemini 2.0 Experimental in dialog.

We're still coasting on the fumes of 1940s data when it comes to water fluoridation. Back then, fluoride toothpaste was a novelty, fluoridated salt was uncommon, and water filters were practically science fiction, let alone ones that can selectively remineralize with or without fluoride.

We're navigating a multi-variable optimization problem blindfolded. We have fluoride inputs from water, toothpaste, and salt, all interacting in poorly understood ways, impacting both cavity rates and, more concerningly, cognitive development.

The IQ Elephant Continues to Loom Large

The potential neurotoxic effects of fluoride are no longer a fringe concern. National Toxicology Program (NTP) monograph is clear: "moderate confidence" that >1.5 mg/L fluoride in drinking water associates with lower IQ in children. 

The technology is here. We can do this right. Modern water filters with remineralization cartridges are the key.

Here's the plan:

1. Factorial Design: Multiple arms to test different combinations of:
   • Water Fluoride Levels:
     • 0 mg/L (placebo - remineralization without fluoride)
     • 0.35 mg/L (half of the current CDC recommendation, exploring potential lower thresholds)
     • 0.7 mg/L (current CDC recommendation)
   • Toothpaste:
     • Standard fluoridated toothpaste (provisioned, with standardized use instructions)
     • Non-fluoridated toothpaste (provisioned, with standardized use instructions)

   • Salt:

     • Fluoridated salt (provisioned)
     • Non-fluoridated salt (provisioned)

     This creates a 3x2x2 factorial design, allowing us to disentangle the effects of each source and their interactions, with a clear focus on the impact of fluoridated salt.

2. Targeted Community Selection: Conduct the study in a community with known poor water quality. This offers multiple benefits:
   • Ethical Appeal: Providing free, high-quality water filters is a significant social good.
   • High Participation Rates: The offer of free water filtration will be very well-received.
   • Enhanced Compliance: Participants receiving a tangible benefit (clean water) are more likely to adhere to the study protocol, including consistent filter cartridge replacement.
3. Randomized, double-blind (as much as possible) allocation of households within the selected community to each of the experimental arms.
4. Longitudinal data collection: Track dental health (cavities, etc.) and, crucially, cognitive development (IQ scores, standardized tests, etc.) over several years.
5. Aggressive confounder control: Detailed surveys on other fluoride intake (dietary sources, etc.), socioeconomic variables, etc. Biomarker analysis (e.g., urinary fluoride) would be ideal for verifying exposure levels and controlling for further confounders.

The ROI is Sky-High - A True Win-Win-Win

The potential return on investment for this RCT is immense. We're talking about a potential population-wide impact on cognitive function, and fine-tuning dental health benefits. The cost of this study is negligible compared to the potential societal costs.

Conclusion: The Time for Inaction is Over. Let's Do This Ethically, Effectively, and Rigorously.

We've relied on outdated assumptions about fluoridation for too long. The potential cognitive risks demand a rigorous, modern investigation. Let's use the technology we have, run the damn factorial RCT with provisioned salt, refined fluoride levels and finally get some high-quality data to inform policy. 

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