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

*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**](https://ntp.niehs.nih.gov/whatwestudy/assessments/noncancer/completed/fluoride) 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.