Risk assessment of holy basil (Ocimum tenuiflorum L. and Ocimum sanctum L.) and some of the component substances used in herbal teas and food supplements
Research report
Published version
Permanent lenke
https://hdl.handle.net/11250/3112874Utgivelsesdato
2023Metadata
Vis full innførselSamlinger
Sammendrag
The Norwegian Food Safety Authority requested the Norwegian Institute of Public Health to assess which amounts of the green parts of the plant holy basil (Ocimum tenuiflorum L./O. sanctum L.) that could be consumed without risk to human health. This plant is used in teas and food supplements sold on the Norwegian market. Information about potential harmful effects of intake of this plant from two extensive literature searches was used in this risk assessment. Safety from both intake of the plant material as such, as well as some individual substances from this plant, was evaluated. The content of plant material of holy basil, assumed to be dried, in teas sold on the Norwegian market was stated as 0.6-2.0 g per tea bag. It was assumed that all of the active substances in the plant were extracted by and ends up in the hot water, as a worst-case scenario due to lack of more specific data. The recommended daily doses of food supplements (dried plant material) varied from 60 to 360 mg in one product and from 800 to1800 mg in another product. Reproductive toxicity, i.e. reduced fertility, appeared to be the most critical adverse effect from intake of holy basil. Intake of one cup of tea or the two food supplements with holy basil plant material may be a risk for embryo implantation loss in pregnant women and for impaired reproduction in males, based on data from animal experiments. A general safe level for all types of preparations of these basil plants seems to be below 1 mg/kg body weight per day. Based on the individual substances methyleugenol, estragole and eucalyptol in holy basil, there may be a risk for adverse health effects at intake of one or more cups of tea per day or from one or both food supplements. Based on eugenol, an intake of three cups of tea per day with the highest level of holy basil reported in tea may be a risk. For β-caryophyllene and ursolic acid, there was not a risk from one, two or three cups of tea per day or from the food supplements. There are a lot of uncertainties in these evaluations, such as regarding whether the few available examples of content of holy basil in teas and food supplements are representative of such products sold in Norway. A question is also how representative the numbers used in the calculations of exposure are for intake of these products in Norway, since composition and levels of the individual substances vary depending on i.a. plant variety, location, methods of cultivation and preparation of the final product. It is also uncertain how relevant the data on adverse effects observed in experimental animals with various extracts of plant material are for risk assessments of other preparations of the plant, such as the dried plant material in teas and food supplements. In conclusion, based on all the available information, precaution is warranted to limit the intake of teas or food supplements with holy basil for pregnant women, and for both men and women wanting to become parents. Since there were no studies on children specifically, the intake of these products is also better avoided during lactation or by children in general.