Praying To St. John's Wort
Among the herbs that have been both lauded and lambasted by the media, St. John's wort (SJW; Hypericum perforatum) has gleaned top honors. Although SJW enjoys a number of human studies indicating an effective and well-tolerated treatment for mild to moderate depression, researchers in a recent study sponsored by the National Institutes of Health in Bethesda, Maryland, found it to be merely equal to placebo and the antidepressant drug Zoloft for treatment of moderately severe depression.1 In fact, both treatments in this particular study actually fared worse than the placebo arm. However, these researchers did not attempt to assess the effectiveness of SJW in mild to moderate depression, for which the majority of studies indicate an appropriate SJW extract to be a safe and effective treatment.
Not all SJW extracts are alike, and only a few have been shown to be effective against human depression. Another area of promise, and concern, for the use of SJW extract is in treating memory disorders and for cognitive function enhancement. One of the active components of SJW is hyperforin, which can alter the amount of the nerve chemical messenger acetylcholine (derived from the nutrient choline).2 However, because altering choline can produce changes in muscle control, SJW is contraindicated in persons with Parkinson's disease or other movement disorders.
Frequent consumption of soy food may reduce the risk of prostate cancer. Does this mean that consuming soy protein powder, isoflavones (the estrogen-like molecules in soy and legumes), or both will prevent or cure prostate cancer? A recent preliminary study showed that a high dose of a red clover-derived isoflavone supplement (160mg/day Trinovin) hinted at an anticancer effect in low-grade prostate tumors.3 Among healthy young men who don't have prostate cancer, the same supplement may raise the amount of dihydrotestosterone (DHT) in the blood over the short term, an apparently undesirable effect in relation to prostate protection.4
Soy protein plus isoflavone ingestion by healthy young men also appeared to have no effect on prostate-specific antigen (PSA) or IGF-1, markers related to prostate cell growth.5,6 These findings suggest that isoflavone consumption would not interfere with validated cancer therapies that influence PSA. They also suggest that if isoflavones have prostate-protecting properties, they likely exert them through other enigmatic ways.
Starch blockers, one of the many ineffective diet fads of the 1980s, are getting some real supporting science.7 Starch blockers are intended to reduce the ability of carbohydrate-digesting enzymes to break down more complex carbs into the absorbable sugars. Starch blockers exist as drugs and are used to manage blood sugar in diabetics, yet weight loss is not a notable side effect.8
Of the starch blockers on the market, one product (Phase 2 Phaseolamin 2250 of Pharmachem Laboratories Inc.) has been subjected to a modest amount of research. In the only study Pharmachem presented at a recent scientific meeting, 11 subjects ate four slices of white bread with 42 grams of margarine and either Phase 2 or a placebo. After the bread-plus-starch-blocker treatment, subjects appeared to absorb two-thirds less of the digested sugars (vs. placebo) from the bread during the four hours afterward.9 Researchers in another study assessed Phase 2's effects on weight loss, but it is unclear whether the weight lost was primarily water, fat or muscle. Blocking carbs may work, but long-term studies need to show this without side effects.
Anthony Almada, BSc, MSc, is a nutrition and exercise biochemist and has collaborated on more than 50 university-based clinical trials. He is the co-founder of EAS and founder and chief scientific officer of IMAGINutrition in Laguna Niguel, California.
1. Hypericum Depression Trial Study Group. Effects of Hypericum perforatum (St. John's wort) in major depressive disorder. J Am Med Assn 2002;287:1807-14.
2. Buchholzer ML, et al. Dual modulation of striatal acetylcholine release by hyperforin, a constituent of St. John's wort. J Pharmacol Exp Ther 2002;301:714-19.
3. Risbridger GP, et al. Induction of apoptosis in low grade prostate cancer by dietary isoflavones. Presented at the Third World Congress on the Aging Male; 2002 Feb 7-10; Berlin.
4. Lewis JG, et al. The effect of isoflavone extract ingestion, as Trinovin, on plasma steroids in normal men. Steroids 2002;67:25-9.
5. Hartman TJ, et al. The effects of animal (non-fat milk) versus soy protein replete with isoflavones on prostate-specific antigen and insulin-like growth factor in men. FASEB J 2002;16:Abstract 735.15
6. Kendall CWC, et al. Effect of soy protein diets on serum PSA levels in hyperlipidemic men. FASEB J 2002;16:abstract 735.14
7. Layer P, et al. Partially purified white bean amylase inhibitor reduces starch digestion in vitro and inactivates intraduodenal amylase in humans. Gastroenterology 1985;88:1895-902.
8. Wolever TM, et al. Small weight loss on long-term acarbose therapy with no change in dietary pattern or nutrient intake of individuals with non-insulin-dependent diabetes. Int J Obes 1997;21:756-63.
9. Vinsono JA. In vitro and in vivo efficacy of an amylase inhibitor for blocking starch absorption. Presented at Experimental Biology 2002; 2002 Apr 24; New Orleans, LA; abstract LB58.