The Evidence for Herbal and Botanical Remedies, Part 2

Anxiety. A controlled clinical trial of chamomile extract for generalized anxiety disorder (GAD) suggested that it may have modest anxiolytic activity in patients with mild to moderate GAD. ²⁶ Another randomized, double-blind, placebo-controlled trial found oral chamomile extract was efficacious and well-tolerated in patients experiencing mild to moderate GAD and may provide an alternative therapeutic anxiolytic for patients with mild GAD. ²⁵ In addition to its anxiolytic activity, c hamomile may also provide clinically meaningful antidepressant activity. ²⁶

Insomnia. Chamomile may have some impact on sleep diary measures (total sleep time, sleep efficiency, sleep latency, wake after sleep onset, sleep quality, and number of awakenings) relative to placebo in adults with chronic primary insomnia, according to a small randomized, double-blind, placebo-controlled pilot trial involving 34 patients. ²⁷ However, a systematic review found no statistically significant difference between any herbal medicine (including chamomile) and placebo, for clinical efficacy in patients with insomnia. A similar, or smaller, number of adverse events per person were reported with chamomile compared with placebo, suggesting safe use. ²⁸

Infantile colic . A small prospective double-blind study on the use of chamomile-containing tea on infantile colic showed statistically significant symptom improvement in tea-treated infants. The study did note, however, that prolonged ingestion of herbal teas may lead to decreased milk intake. ^29,30

Adverse effects

As noted earlier, a systematic review found that the number of adverse events per person reported with chamomile was comparable to the number associated with placebo, suggesting that it is safe. ²⁸

The bottom line

Chamomile appears to be safe with minimal adverse effects and may be effective for the treatment of anxiety, insomnia, and infantile colic.

Rosemary

Overview

Rosemary, officially known as Rosmarinus officinalis , is a medicinal evergreen plant native to the Mediterranean area that appears to increase microcapillary perfusion. ³¹

Topical rosemary oil may be useful in the treatment of alopecia, with minimal adverse effects.

Alopecia. A randomized double-blind controlled trial found that essential oils including rosemary oil (as well as thyme, lavender, and cedarwood) massaged into the scalp improved hair growth in almost half of patients with alopecia areata after 7 months. ³² Another randomized trial comparing rosemary oil to minoxidil 2% for androgenetic alopecia showed a significant increase in hair count at the 6-month endpoint compared with the baseline, but no significant difference was found between the study groups regarding hair count either at Month 3 or Month 6 ( P >.05). ³¹

Adverse effects

In the randomized trial described above comparing rosemary oil to minoxidil 2%, adverse effects appeared to be rare for topical rosemary oil. Scalp itching was more frequent in the minoxidil group. ³¹

The bottom line

Topical rosemary oil may be useful in the treatment of alopecia with minimal adverse effects.

Coffee/caffeine

Overview

Coffee is one of the most widely used botanicals with approximately 3.5 billion cups of coffee consumed per day worldwide. It is a popular beverage because of its unique aromatic taste and its use as a central nervous system stimulant. The coffee tree (genus coffea) is found throughout Latin America, Africa, and eastern Asia. Two of the most common commercially grown species are Coffea arabica (Arabicas) and Coffea canephora (Robusta). Processing and roasting methods may differ and produce variations in flavor and aroma. The degree of roasting also affects the caffeine content.