BOTANICAL MEDICINE

Cranberry juice and concentrated cranberry extracts, which contain a class of antioxidants known as anthocyanins, have recently become widely used for the prevention (and occasionally treatment) of urinary tract infections. Clinical studies have shown that it is effective, but not for all populations (Cimolai & Cimolai, 2007). The effectiveness of cranberry is thought to be related to its antimicrobial properties and possibly because it prevents bacteria from sticking to the urinary tract. In addition to its utility for treating urinary tract infections, cranberry is also used in holistic therapies that focus on the heart. Accumulating evidence indicates that cranberry, as well as other fruits rich in antioxidants, may reduce the risk of cardiovascular disease by increasing the resistance of LDL to oxidation, inhibition of platelet aggregation, reducing blood pressure, and reducing inflammation in circulatory vessels (see McKay and Blumber, 2007).

Earlier clinical studies in which saw palmetto was compared to finasteride in the treatment of benign prostatic hyperplasia (BPH) report that the herbal preparations were comparable in efficacy.  However, more recent studies have found no differences between saw palmetto and placebo (Tacklind et al, 2009).

Note that saw palmetto is not effective for the prevention or treatment of prostate cancer.

Saw palmetto is very well-tolerated with rare side-effects.

Many plants contain chemicals called phytoestrogens that have effects similar to human estrogen. One example of phytoestrogens are the isoflavones found in soy, red clover, and flaxseed.

Americans take isoflavones most commonly to treat menopausal symptoms. Although some studies question the effectiveness of isoflavones, one 2006 study noted that soy protein appears to reduce total cholesterol levels, and red clover reduces triglycerides while increasing HDL cholesterol. Overall, the study concluded that isoflavones in soy and red clover appear to have a “small but positive” effect and would be beneficial for menopausal women.

Rarely, high quantities of soy or isolated isoflavones cause bowel irritation.

People with allergies to soy or flax should use caution.
There is some uncertainty about the safety of high doses in patients with breast cancer.
Children should not be given dietary supplements that contain high levels of phytoestrogens because they may affect brain development.

Echinacea, originally a Native American remedy, has gained popularity for treating the symptoms of colds, flu, and respiratory infections. Some research indicates that echinacea has the potential to boost immune cell response, but only certain preparations of echinacea are able to do so, such as fresh pressed juice or isolated polysaccharides (Linde et al., 2006). A meta-analysis of 14 clinical studies on the effects of echinacea on the duration and severity of the common cold (Shah et al., 2007) indicated that pre-treatment with echinacea reduced the odds of developing a cold by 58 percent and reduced the average duration of the infection by 1.4 days. These and other results support the use of echinacea for prevention and treatment of the common cold.

Additional studies are taking place to explore the use of echinacea as a cancer treatment or preventive medicine. Results of a 2005 study (Miller, 2005) with mice found that daily consumption of echinacea was preventive; it extended the life span of aging mice, significantly lessened the effects of leukemia, and it extended the life span of the mice with leukemia. While the results of this mouse study are promising, it is important to keep in mind that animal studies cannot always be assumed to demonstrate clinical efficacy in humans.

Echinacea is very well-tolerated.

People with allergies to ragweed may be allergic to echinacea.

Used to treat mild to medium depression, has been shown to inhibit the reuptake of serotonin similar to fluoxetine (Prozac) and other serotonin reuptake inhibitor drugs. Research with Prozac and other SSRIs have shown that increasing the levels of serotonin at the nerve synapse can have ameliorative effects on depression. St. John’s Wort also possesses the ability to modulate interleukin-6 activity, which may also play a role in affecting mood. Other mechanisms contributing to its antidepressant actions have been suggested, including inhibition of serotonin receptor expression and catechol-O-methyltransferase, an enzyme that degrades catecholamine neurotransmitters, which, like serotonin, are involved in the modulation of mood.

Ginkgo has been well-investigated clinically, particularly for its efficacy in improving memory and cognitive functions in elderly people suffering from impaired cerebral circuation. Some studies state that its benefits are inconsistent or unconvincing (Birks et al. 2007; Carlson et al 2007). However, numerous other clinical studies have reported positive outcomes of Ginkgo biloba treatment for the prevention of cognitive deficits in the elderly (Ramassmay et al. 2007).

Part of the difficulty of evaluating these differing outcomes is related to the methods used in each study, such as the selection of the patient populations, length of treatment, dose of medication, and variability in the composition of the treatment medication. See Dekosky et al. (2006) and Weinmann et al. (2010) for discussions.

Reports of adverse reactions have been extremely rare. (It may rarely cause GI upset.)

Can enhance bleeding risk in patients taking anticoagulants or antiplatelet drugs.