Label Review
March 1999; Volume 1: 30-31
With Comments from Adriane Fugh-Berman, MD
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Price: $14.99/8 fl. oz. (236 ml)
Discussion
The vagaries of the language on the label make it difficult to dispute specific claims. This product apparently aims to gather up consumers who have heard anything good about phytoestrogens, flaxseed oil, or evening primrose oil, but this combination makes little sense. The words "high risk" are not attached to any condition or disease, possibly to maximize the product’s attractiveness to any consumer at high risk for anything.
Soy and flax are sources of different types of phytoestrogens (isoflavones for soy; lignans for flax). Lignans and lignan precursors in flax demonstrate some anticancer effects in animal models.1 The amount of lignans in this preparation, however, is inconsequential, as it contains 3 g of "flaxseed particulate" (presumably crushed flaxseed) and only 5 mg of lignans. Studies of flaxseed for menopausal symptoms, for example, have used a dose of 10-50 g flaxseed daily.
Flaxseed oil, which constitutes most of this product, is similar to fish oil in terms of being rich in omega-3 fatty acids; this class of compounds inhibits platelet aggregation, has anti-inflammatory effects, and has immunomodulating effects.2 Most studies of fish oil administered amounts equivalent to 3-4 g daily of omega-3, so this supplement, which provides 5115 mg omega-3 fatty acids, does fall in a therapeutic range.
Evening primrose oil is high in omega-6 fatty acids, especially gamma linolenic acid (GLA), a precursor of prostaglandin E. Evening primrose oil is popular for a variety of inflammatory conditions; there is some evidence of its efficacy for mastalgia.3 Short-term use appears safe, but there is a theoretical concern that long-term intake could increase inflammation due to slow accumulation of arachidonate in tissues.4
Several compounds derived from soy, e.g., purified isoflavones, protease inhibitors, and saponins, have apparently been added to this formula. While isoflavones in food products have a number of beneficial effects (see Alternative Therapies in Women’s Health, Premiere issue, pp. 1-4), the long-term safety of food-free isoflavones has not been established.
Saponins are steroid or triterpene glycosides widely distributed in plants. Although saponins are active principles in a number of medicinal plants,5 they are not considered to be the active principles in soybeans.
Rosemary and vitamin C, in tiny amounts, might be preservatives but in the existing doses are inconsequential therapeutically.
The protease inhibitors present in this formulation occur naturally in soybeans, but in soyfood product protease inhibitors are deactivated by heat processing. Protease inhibitors compose an important class of anti-HIV drugs but have no place as a dietary supplement.
In summary, this supplement is predominately flaxseed oil fortified with an odd mix of compounds of dubious therapeutic value. Flaxseed oil is a good source of omega-3 fatty acids and may have some cardioprotective effects. This product also apparently contains some crushed flaxseed. While there is evidence for possible health benefits of lignans in flaxseed, this product does not contain sufficient quantities for any therapeutic effect. "The Essential Woman" probably has no advantage over plain flaxseed oil, which can be purchased more cheaply.
References
1. Thompson LU, et al. Variability in anticancer lignan levels in flaxseed. Nutr Cancer 1997;27:26-30.
2. Uauy-Dagach R, Valenzuela A. Marine oils: The health benefits of n-3 fatty acids. Nutr Rev 1996;54:102-108.
3. Kleijnen J. Evening primrose oil. BMJ 1994;309: 824-825.
4. Phinney S. Potential risk of prolonged gamma-linolenic acid use. Ann Intern Med 1994;120:692.
5. Lacaille-Dubois MA, Wagner H. A review of the biological and pharmacological activities of saponins. Phytomedicine 1996;2:363-386.
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