[briandon]

At least one decades-old study that had purported to show that the herbicide glyphosate posed no health (esp cancer) risk to humans was retracted in late 2025 (https://www.nytimes.com/2026/01/02/climate/glyphosate-roundu...). Glyphosate may be applied multiple times in a season, both to control weeds but also onto the actual desired crop (i.e. the stuff that gets turned into food for humans and for other animals) as a desiccant a week or two pre-harvest. The official line is that glyphosate that isn't absorbed directly by leaves and other above-ground plant tissues "tightly binds" to soil and is quickly and completely broken down by soil bacteria, though it is also admitted that plant roots can absorb glyphosate and that it can subsequently be transmitted throughout plants. So I would not discount the possibility that some level of glyphosate accumulation in the soil and bioaccumulation in food crops could also be occurring alongside residues from spraying.

In other words, dietary fiber in general or specific forms (e.g. Metamucil aka Psyllium husk) could be effective in lowering CRC risk or could have been so in the past but consumption of real-world dietary fiber in the current era in which glyphosate-based herbicides are in increasingly wide use could now be increasing cancer risks.