Hypothesis: Sequestering cobalt in the intestines to reduce colon cancer

Many studies have found an association between cobalt levels in the body and colon cancer. For instance this 2021 study from Iran found such an assocation:

The highest concentrations of heavy metals were found in the central part of the province and particularly counties with higher amount of cobalt were shown to be associated with higher ASR of men with colon cancer. In contrast, selenium concentrations were higher in areas with lower ASR of colon cancer in men. A significant regression equation for men with colon cancer was found (F(4,137) = 38.304, P < .000) with an adjusted R2 of 0.77. 

See "Association between heavy metals and colon cancer: an ecological study based on geographical information systems in North-Eastern Iran," 2021, https://pubmed.ncbi.nlm.nih.gov/33858386/.

Cobalt is highly reactive in some forms and can cause cancer.

Cobalt and cobalt compounds that release cobalt ions in vivo are reasonably anticipated to be human carcinogens based on sufficient evidence of carcinogenicity from studies in experimental animals and supporting data from studies on mechanisms of carcinogenesis. Mechanistic data indicate that the release of cobalt ions in vivo is a key event for cobalt-induced carcinogenicity. The available data show that cobalt metal and cobalt compounds that release cobalt ions in vivo (regardless of their solubility in water) act via similar modes of action to cause similar types of effects, including cell death, DNA damage, and cancer, and that the cobalt ion is largely responsible for the toxicity and carcinogenicity (IARC 2006b; NTP 1998; 2014).

(Online at https://www.ncbi.nlm.nih.gov/books/NBK590837/)

Some forms of cobalt are highly stable, though. Cobalt manganese oxide (CoMnO) for example is typically insoluble in water and very stable. I think it could be helpful to periodically drink water that has the right compounds of manganese oxide to bind (i.e., sequester) cobalt in the intestines and thus lower its carcinogenicity. Perhaps dedicated drinking fountains could be utilized for this purpose and help turn the tide in the rising wave of colon cancer cases. Manganese is already present in tiny amounts in our tap water.

I wonder whether selenium tends to sequester cobalt, too, given that it was slightly protective against colon cancer in the Iran study above.