Herbs for Health: Nutritional Supplements

Enlarge Image Image Gallery A new study casts doubt on whether garlic really does lower cholestrol.

 A supplement to the Herb Companion from the American Botanical Council and the Herb Research Foundation.   

The garlic debate

Although numerous clinical studies, involving a total of thousands of subjects, have shown that garlic reduces cholesterol levels, a six-month double-blind, randomized study at Oxford University of 115 subjects ages thirty­-five to sixty-four found no significant difference in cholesterol levels between the treatment and placebo groups at the end of the study. Those in the treatment group had received 900 mg of a garlic tablet standardized to 1.3 percent allicin three times daily. The results question the methodology of previous garlic studies. The researchers called for a rigorous, long-term trial of at least 1,000 subjects to determine whether garlic does in fact lower cholesterol.(1)

The best ginseng

Traditionally, the roots of Asian ginseng (Panax ginseng), valued for their adaptogenic or tonic effects, have been considered of high quality only if they are at least four or five years old. A 1984 study showed that the highest yields of the primary active constituents, called ginsenosides (770 mg per root of Korean-grown Asian ginseng), are obtained at the end of the summer of the plant’s fifth year, as the root doubles in weight between the fourth and fifth years. After the fifth year, root size and ginsenoside content increased only slightly. Because of this finding, the roots are normally harvested in the fall of the plant’s fifth or sixth year.

In 1994, chemists with Agriculture and Agri-Food Canada measured the ginsenoside content of one-, two-, three-, and four-year-old roots of American ginseng (P. quinquefolius) growing in artificial shade. From the end of the third year to the end of the fourth year, the ginsenoside content increased from 4.74 percent of dried root weight to 7.83 percent. A 1995 trial yielded similar results, confirming that high-quality material should be at least four years old. Ontario is the leading producer of ginseng in North America, followed by Wisconsin and British Columbia.(2,3)

Castor beans as contraceptive

In the search for new contraceptives, researchers have been evaluating traditional methods throughout the world. A recent joint Jordanian/Saudi Arabian study found that feeding rabbits poisonous castor beans (Ricinus communis) prevented conception, although the mechanism of action and active compound have not been determined. Castor beans have been used as a contraceptive in many countries, including India and Korea. In Algeria, women dip a castor bean in warm rabbit blood before eating it. Egyptian women have been reported to eat one bean after childbirth in the hope of preventing pregnancy for at least nine months.