Do Botanical Medicines Work? An Expert Explains.

If I had to guess, I’d estimate that nearly every reader of this blog has, at one time or another, tried botanical medicines. Perhaps it was for hot flashes, or depression, or to alleviate cold symptoms. It seems remarkable to me that names like Ginkgo Biloba, St. John’s Wort and Kava Kava roll off our tongues so easily, as if we were all botanists.

That we are so familiar with the potential benefits of these and other odd-sounding plants reveals not only the high level of consumer interest in natural medicines, but also how often we read about them in the news media. The headlines announce compelling evidence that something proves to be effective one week, followed by an article that contradicts those findings not long after. It’s hard to know what to believe if you’re not a trained researcher.

American Botanical CouncilThat’s why last week, I listened to a webinar led by Mark Blumenthal, founder and executive director of The American Botanical Council on the Science of Herbal Medicines: What Works And Why. He walked listeners through more than two dozen botanicals and explained what the studies of the studies concluded. That’s right. There may be dozens of research studies on a particular botanical, but only a small percentage of them meet high enough standards to be included in a meta-analysis of their findings. Only the studies that compare the plant to a placebo in a randomized-controlled- trial and involve a large number of participants over a long period of time were included in these meta-analyses. So instead of looking at just one or two research trials that may be skimpy, an examination of all the evidence collected from “gold-standard” studies reveal what the data shows, without bias.

You can listen to the entire presentation at Terry Talks Nutrition, which hosted the webinar. But I’ll give you a snapshot here. I chose five botanicals that I’d think are most relevant to women in our age group:

cranberries for UTIs

Cranberry- for urinary tract infections

An examination of  13 random control trials involving 1600 subjects for six months showed that Cranberry may be most beneficial in women with recurrent UTIs. However, when 14 additional studies with nearly 4500 participants was added to the meta analysis, researchers concluded that cranberry juice is less effective than previously indicated and thus cannot be recommended for the prevention of UTIs at this time.

St John’s Wort – for mild, moderate depression

Twenty-nine random-controlled-trials, involving nearly 5500 patients, were reviewed in this meta-analysis. Eighteen compared this herb to placebo, while 14 compared it to conventional drugs. Researchers concluded “the available evidence suggests that the hypericum extracts are superior to placebo in patients with major depression. It was shown to be as effective as standard antidepressants, with fewer side effects.

Black Cohosh- for vasomotor symptoms of menopause

This is one of the most popular herbs in North America. Out of the 31 studies that have been done, only nine met the criteria for the meta-analysis. Researchers found that this herb, used alone, improved hot flashes by 26 percent. But when combined with other botanicals, such as St. John’s Wort, it showed a 41 percent improvement. “Results are consistent with those of earlier reviews suggesting a benefit of Black Cohosh in reducing vasomotor symptoms” of menopause.

However, a more recent systematic review, published by the Cochrane Collection (a library for high quality information about the effectiveness of health care) looked at 16 random controlled trials involving just over 2000 menopausal women. This time, Blumenthal explained, perhaps due to a large range of doses, and treatment durations, the review “did not show an adequate basis for efficacy.”

Butterbur for severe headachesButterbur Root Extract- for severe headaches and migraines

This herb is more well known in Europe, where it was introduced in 1972, than in the U.S.  Two high quality trials were reviewed. Based on 150 mg/day of a Butterbur Root Extract product out of Germany called Petadolex®, used for three to four months, the frequency of migraines was reduced by 15 percent compared to placebo. Researchers concluded that there is “moderate evidence for effectiveness of butterbur root extract in preventing migraines.” They recommended further rigorous studies to strengthen the evidence and to evaluate a higher dose of 300 mg/day.

But even with that caveat, last year, researchers at two U.S. medical groups, The American Academy of Neurology and the American Headache Society concluded that “Petadolex® is effective in reducing the frequency and severity of episodic migraines.”

Red Yeast Rice – For lowering cholesterol

Researchers evaluated 93 studies (out of 372), involving 9600 people and the combined results showed significant reduction of triglyceride and LDL levels and an increase in HDL (good cholesterol) compared with placebo. The effects of Red Yeast Rice on Lipids appear to be similar to statins and superior to fish oils.

And Green Tea…

Green tea can help reduce the risk of some cancersMark Blumenthal threw in a brief discussion about green tea. He explained that there is compelling evidence, based on the findings of 17 long-range, large-scale population studies, that drinking three to five cups of green tea daily can decrease the risk of ovarian cancer by as much as 32 percent and by 23 percent for endometrial cancer.

The American Botanical Council can be a reliable, unbiased source for information about herbal medicine. Though it’s a membership organization, its website offers open access to some great information including a database of plants and related materials used in dietary supplements, aromatherapy and natural cosmetics.

Note:  The source of this information and quotes used in this blogpost came from The American Botanical Council’s Mark Blumenthal and the slides he used in his presentation.