According to an abstract, researchers set out to study the effects, if any, that green tea and/or licorice aqueous extracts would have on the thyroid function of male albino rats intoxicated with Dimethylnitrosamine, a carcinogenic compound that occurs especially in tobacco smoke.

The team split 40 rats into several groups to control the administration of green tea, licorice, and a combination of both substances, then measured results over a period of four weeks.

The results indicated that "aqueous extract of green tea may be effective in amelioration of biochemical effects and histopathological lesions induced by DMN," stated the abstract.