A common blue food dye seems to have caused the deaths of 2 patients after it was used to color the liquid food pumped into their stomachs, according to a new report in the New England Journal of Medicine.
The patients had been given food with FD&C blue dye No. 1, after which their skin and blood turned a bluish-green. Several hours later the patients, a 12 month old with Down's Syndrome and a 54 year old with kidney failure, were dead.
The blue dye, made of coal tar, is routinely added to the liquid food to help doctors see whether any of the food is escaping from the stomach. In healthy people, the food and the dye are not thought to leave the digestive tract.
The three cases involved patients who had digestive track tissues being destroyed by sepsis, a serious infectious condition. The condition apparently allowed the dye to enter the bloodstream, causing a deadly drop in blood pressure (hypotension) and an increase in acid levels in the body's fluids and tissues (acidosis).
According to the researchers:
"During sepsis, gastrointestinal permeability increases because of enterocyte death and loss of barrier function at intercellular gaps. Thus, substances that are otherwise nonabsorbable may be absorbed during sepsis."
The researchers note that Blue dye #1 was approved by the FDA in 1982 after experiments in healthy animals indicated that he dye was nontoxic and not absorbed.
Concerning the potential health dangers of the dye, the authors state:
"Blue dye no. 1, a triphenylmethane dye, is a potent inhibitor of mitochondrial respiration in vitro and reduces oxygen consumption by a factor of eight in mitochondrial preparations in vitro. It appears to inhibit energy transformation by blocking the adenine nucleotide translocator (as is the case with atractyloside)."
The researchers note that although both patients were hospitalized with serious illnesses, their condition was improving before they received the dye.
Although researchers say the dye is not dangerous to the vast majority of people, they are recommending "judicious use" in patients with possible increased gastrointestinal permeability.
New England Journal of Medicine October 5, 2000; 343; 1047-1048.
The blue dye in question is made from "coal tar", as are many other food dyes and other products such as hair dyes. This is makes it a potentially very dangerous substance, due to the high content of toxic substances, such as mercury, lead and fluoride, found in coal.
A recent report in the USA Today said that studies suggest that coal tar may cause leukemia, non-Hodgkin's lymphoma, and multiple myeloma (USA Today Magazine, January 2000).