There is no evidence to suggest that humic acids, of which fulvic acid is derived, prevent or hinder cancer, according to WebMD. However, the acids have been identified as a group of compounds capable of producing carcinogens in drinking water, states Northeastern University.
As of 2015, positive evidence regarding the medical and nutritional value of fulvic and humic acids is not available, states WebMD. In addition, research has associated humic acid with joint disease, circulatory disease and thyroid disease.
Humic acids have been shown to interact with halogens, toxic metals and micro-nutrients commonly present in drinking water, states the Humic Acid Research Group of Northeastern University. Reactions with halogens produce a variety of carcinogens. Humic acid reactions with toxic metals can increase or decrease the toxicity of such compounds, while reactions of the acids with micronutrients can increase or decrease the bio-availability of those micronutrients.