Borage seed oil Obtained from the seeds of Borago officinalis L., family Boraginaceae, this

oil contains 20–26 percent GLA. 29 It is currently marketed in the form of capsules, each containing 1,300 mg of the oil, equivalent to 300 mg of GLA. Borage seeds have been shown to contain small amounts of pyrrolizidine alkaloids, including the known hepatotoxin amabiline. That alkaloid was not detected in samples of the seed oil down to levels of 5 µg/g. Consumption of 1–2 g of borage seed oil daily could, nevertheless, result in an intake of toxic unsaturated pyrrolizidine alkaloids (UPAs) approaching 10 mg. The German federal health agency now limits inter- nal consumption of such products to not more than 10 µg of UPA daily. 33

The fact that GLA-rich fatty oils are now available commercially from three different plant sources does not alter the conclusion that the product’s efficacy for any condition remains unproven. Likewise, its safety for long-term usage requires additional verification.

Raspberry leaf Raspberry leaf tea, an infusion prepared from the dried leaves of Rubus idaeus L. or R. strigosus Michx. of the family Rosaceae, has a considerable reputation as “a traditional remedy for painful and profuse menstruation and for use before and during confinement to make parturition easier

and speedier.” 34 Because of its astringent properties, it is also used to treat diarrhea, an application previously discussed in Chapter 3 . The scientific evidence supporting the effects of raspberry leaf on the uterus is scanty, and clinical evidence is even more so. However, a 1999 study reported a positive influence on labor outcomes. 35

Beckett and colleagues have carried out the most substantial pharma- cological testing to date, using isolated tissues of guinea pigs and frogs. 36 They concluded that aqueous raspberry leaf extracts contain a number of different active constituents, the actions of which are mutually antagonis- tic, including (1) a smooth muscle stimulant, (2) an anticholinesterase, and (3) a spasmolytic. The authors opined that it would be impossible to predict an overall clinical effect from observation of or studies with animals.

There is also a difference in the effect of the herb on pregnant versus nonpregnant human uterine strips. It was without effect on the latter but promoted contraction of normal human uterine strips at ten to sixteen weeks of pregnancy. 37

160 Tyler's herbs of choice: The therapeutic use of phytomedicinals Such findings seriously complicate any attempt at the evaluation of the

efficacy of the herb for any of its folkloric uses. Evaluation is further ham- pered by the absence of any long-term toxicity data, including teratogenic- ity. This is an especially serious omission in view of the fact that one of the

recommended uses of raspberry leaf tea is to alleviate morning sickness. 38 Doses also are relatively large. At least one source recommends preparing

a tea by steeping 30 g of leaves in 480 mL of boiling water for thirty min- utes and drinking the entire quantity to promote an easy labor. 39 In view of these factors, it seems best to adhere to the admonition that the consumption of any herbal product of unproven safety and efficacy is especially unwise during pregnancy. Deviation from this rule will cer- tainly produce more harm than good.

Hyperthyroidism

Also referred to as thyrotoxicosis or Graves’ disease, hyperthyroidism is

a very common endocrine disorder that may arise from a number of different causes. It is characterized by symptoms that may include weakness, weight loss, nervousness, tachycardia, exophthalmos, and goiter.

Borage seed oil Obtained from the seeds of Borago officinalis L., family Boraginaceae, this