Black cohosh: flash in the pan for menopause?
With the Women's Health Initiative indicating that combined estrogen plus progestin therapy poses increased health risks amongst women with an intact uterus,1 the search for an alternative has heated up. One herb claimed to cool menopausal symptoms is black cohosh (Cimicifuga racemosa). Despite being a native North American plant, it is in Europe where its extracts are widely promoted to treat hot flashes and other menopausal "uncomfortables."
In the few controlled clinical trials conducted on black cohosh, a product called Remifemin has been used most frequently. A recent review of published studies asserted that the effectiveness of black cohosh is not borne out by rigorous clinical trials.2
In a recent six-month study (conducted by the makers of Remifemin), researchers found significant improvements in symptoms, but no placebo group was used.3 Additional studies—well-designed and long-term (more than six months)—are needed.
Niacinamide A Diabetes Shield
Unlike its flushing cousin niacin, niacinamide (aka nicotinamide) in high doses has no effect on blood cholesterol, but may deter the progression or even development of type 1 diabetes (T1D). Those with T1D have lost the majority of cells in the pancreas—beta cells that produce and release insulin. High-dose nicotinamide to prevent T1D appears to attenuate immune-mediated destruction of beta cells by acting as an antioxidant and blunting immune attack.4,5 In one study with 55 first-degree relatives of patients with T1D, researchers found no significant decrease or delay in developing the disease after two years of supplementation with 2.4g/day.6
However, the much larger ENDIT (European Nicotinamide Diabetes Intervention Trial) study involving 552 T1D high-risk subjects promises a more definitive answer when its results are released in 2003.7 Recent studies also suggest that elderly people with type 2 diabetes are nicotinamide deficient and would benefit from supplementation.8
Potassium's Lucky Strike
People with low potassium intake have been shown to have an increased risk of stroke.9 Potassium may reduce stroke risk by dropping blood pressure, the "stickiness" of blood platelets, or by improving the functional integrity of blood vessels.10 In a recent study, researchers examined the link between potassium (both in the diet and blood) and overall incidence of stroke among 5,600 people ages 65 or older from four different communities who had no history of stroke.11
After baseline evaluations that included measurement of serum potassium and dietary assessments, subjects were followed for up to eight years. Those subjects taking diuretics and showing a lower initial serum potassium concentration had a 2.5 times greater stroke risk compared with those who had higher blood potassium. Amongst diuretic nonusers, those with the lowest dietary potassium intakes had a 1.76 times greater risk of stroke compared with those with the highest intakes. Although this study attests to the theory that potassium levels are a predictor of stroke risk, what remains to be seen is whether directly increasing potassium intake (foods and/or supplements) prevents stroke amongst diuretic users or nonusers.
Anthony Almada, BSc, MSc, is co-founder of EAS and founder and chief scientific officer of IMAGINutrition in Laguna Niguel, California.
1. Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA 2002;288:321-33.
2. Borrelli F, Ernst E. Cimicifuga racemosa: a systematic review of its clinical efficacy. Eur J Clin Pharmacol 2002;58:235-41.
3. Liske E, et al. Physiological investigation of a unique extract of black cohosh (Cimicifugae racemosae rhizoma): a 6-month clinical study demonstrates no systemic estrogenic effect. J Womens Health Gend Based Med 2002;11:163-74.
4. Gale EA. Theory and practice of nicotinamide trials in pre-type 1 diabetes. J Pediatr Endocrinol Metab 1996;9:375-9.
5. Kim KA, et al. IFNgamma/TNFalpha synergism in MHC class II induction: effect of nicotinamide on MHC class II expression but not on islet-cell apoptosis. Diabetologia 2002;45:385-93.
6. Lampeter EF, et al. The Deutsche Nicotinamide Intervention Study: an attempt to prevent type 1 diabetes. Diabetes 1998;47:980-4.
7. Schatz DA, Bingley PJ. Update on major trials for the prevention of type 1 diabetes mellitus: the American Diabetes Prevention Trial (DPT-1) and the European Nicotinamide Diabetes Intervention Trial (ENDIT). J Pediatr Endocrinol Metab 2001;14(Suppl 1):619-22.
8. Laube H, et al. Nicotinamide level is low in elderly type 2-diabetic patients. Diabetes 2002;51(Suppl 2):A401.
9. Fang J, et al. Dietary potassium intake and stroke mortality. Stroke 2000;31:1532-7.
10. Levine SR, Coull BM. Potassium depletion as a risk factor for stroke: will a banana a day keep your stroke away? Neurology 2002;59:302-3.
11. Green DM, et al. Serum potassium level and dietary potassium intake as risk factors for stroke. Neurology 2002;59:314-20.