Coriander – known as cilantro in the US – has a long history of use, dating back to the early Greek era. It has been used as a medicinal herb and is known to have broad antimicrobial activity.
The essential oil, obtained by steam distillation of the seeds, is used by the food industry as a flavouring, and also by the fragrance industry. It major chemical constituent is linalool, which makes up around 70 per cent.
The new study, accepted for publication in the journal Food and Chemical Toxicology, was conducted by George Burdock of The Burdock Group and Ioana Carabin of Women in Science. The research reviews, descriptions, compilations, and analysis were funded by food ingredients firm Philip Morris USA.
The study authors reviewed a raft of scientific literature. Based on the results, as well as an in depth look at its uses through history, they concluded:
“Based on the history of coriander without reported adverse effects, lack of its toxicity in limited studies and lack of toxicity of its major constituent, linalool, the use of coriander as an added food ingredient is considered safe at present levels of use.”
The authors took into account the findings of a 28 day rat study, which gave a no observed effects level (NOEL) of 160mg/kg/day. They also looked at a developmental toxicity study, in which the maternal no observed adverse effects level (NOAEL) was seen to be 250mg/kg/day, and the developmental NOAEL 500 mg/kg/day.
Other evidence explored concluded that the oil is not clastogenic – that is, causing breakage of chromosomes. However the spice and some extracts have also been studied for mutagenicity and the results are said to be “mixed”.
For its part, linalool is non-mutagenic.
“Coriander oil is irritating to rabbits, but not humans; it is not a sensitizer, although the whole spice may be,” the authors wrote.
Food and Chemical Toxicology
Published online ahead of press, 12 November 2008Doi: 10.1016/j.fct.2008.11.006"Safety assessment of coriander (Coriandrum sativum L.) essential oil as a food ingredient"
Authors: George Burdock, Ioana Carabin