c The clinical cases are arranged in decreasing order of apparent severity of the adverse effects.
d In the initial extraction, fresh (not dried) leaves and flowers of Larrea tridentata were lightly ground in ethanol:water (90:10) at 1:2.5 (w/v). (Heron and Yarnell, 2001).
e One other case report involving cancer exists (Smith et al., 1994), but it was omitted from this table for the following reasons. The cause and effect relationship between the subject’s intake of chaparral and the development of cancer was not well documented. The subject (a 56-year-old female) used chaparral tea (3–4 cups/d) for 3 mo during the 1.5-y period prior to the diagnosis of cystic renal cell carcinoma. The subject also used taheebo tea (5–6 cups/d) for 6 mo almost 20 y earlier. Taheebo tea is reported to contain quinones. The date of the onset of the malignancy is unknown. In this report the correlation between the subject’s cancer and the consumption of chaparral tea seems to have been made on the basis of the known effects of nordihydroguaiaretic acid (the major lignan in chaparral) in causing multiple renal cysts in rats. Thus there is no evidence that the subject’s renal cancer was the result of consumption of chaparral.