Humic acid is gaining a toehold as a supplement that’s meant to improve a person’s immunity and provide other benefits. However, there are no clinical trials that demonstrate the safety of humic acid as a supplement for humans, according to the U.S. Federal Drug Administration. While it's sometimes used in animal feed, humic acid's benefits to livestock vary from animal to animal. Humic acid is, however, considered beneficial to plants and often is used as a complement to fertilizer.
Humic acid is a major part of the humic substances in soil. Humus is made of natural organic compounds. These are formed in soil during a process called humification, which involves decomposition of animal and plant residues by microorganisms. Humic acid is a commercial term that is used to identify the combined humic and fulvic acid content found in these naturally occurring dark brown soil constituents, according to Natural Environmental Systems LLC.
Companies that market humic acid supplements claim that these support immune function, lead to enhanced cellular health and boost the body’s inflammatory response, according to Ray Sahelian, a nationally known physician and author of “Mind Boosters.” However, no U.S. studies back this use.
Use of humates as a feed supplement was sparking increasing interest in the agricultural community and among scientists in early 2010, reports the University of Arizona Department of Animal Sciences, which had launched a study on the subject. Humates are humic acid in a solid state, and have the same chemical properties. Humates already are used as a supplement in the dairy, pork and equine industries, and one experiment on beef cattle showed that the more humates the cattle ingested the less they ate. These cattle, however, still gained weight. This occurred in poultry studies as well and also led to a decrease in illness, according to lead researcher C.P. McMurphy.
A report by K.M.S. Islam, A. Schuhmacher and J.M. Gropp in the “Pakistan Journal of Nutrition” advises that humic acid has anti-inflammatory, antibacterial, antiviral and immune-boosting benefits to animals. But its use as a growth promoter for animals is not supported by studies done with rats, making this use questionable. Also, it is difficult to compare effects of humic acid preparations because they are derived from different sources and undergo varying preparations, the authors advise.
Humic acid is commonly used as a soil aid in growing plants. It is not a fertilizer because it doesn’t provide nutrients to plants directly. However, it is a good complement to fertilizer. The benefits include adding organic matter to soils that may be organically deficient, higher chlorophyll synthesis, improved seed germination, boosted nutrient uptake, better fertilizer retention, increased root vitality and the stimulation of beneficial microbial activity, according to NES.
The FDA sent an Aug. 19, 2009, warning letter to a company that markets humic acid supplements. The letter stated that the company violated FDA regulations because there was not enough evidence that its humic acid supplements were safe as a dietary ingredient. The letter also stated that there was “inadequate information to provide reasonable assurance that such ingredient does not present a significant or unreasonable risk of illness or injury.”
In addition, a report by Francesca Bernacchi published in the Oxford Journal “Mutagenesis” concludes that humic acid needs further study in regard to potential cell DNA damage that can cause mutations. Humic acid given to mice led to chromosomal abnormalities in mouse intestine cells, Bernacchi also noted.