December 2, 2003
THE PRODUCT AND WHAT IT'S MARKETED FOR:
Evening primrose oil is a clear, golden-yellow oil extracted from the seeds of the evening primrose, a wildflower native to North America. It is a widely used medicinal that ranked 10th in sales among all herbal dietary supplements, according to the American Botanical Council.
Taken primarily in capsule form and occasionally used topically, evening primrose oil is high in an essential omega-6 fatty acid called gamma-linolenic acid (GLA). According to a review of evening primrose oil conducted by ConsumerLab.com, an independent testing organization, the body is often able to produce sufficient amounts of GLA from foods containing oils from corn, sunflowers, safflowers, soy, peanuts and plants like flaxseed. However, there are several conditions, from heart disease and rheumatoid arthritis to dermatitis and menopausal symptoms, in which the body's production of GLA may be reduced. That's where evening primrose oil seems to be most helpful.
It acts as an anti-inflammatory and is used to treat chronic diseases such as diabetic neuropathy, Raynaud's disease, skin conditions including eczema and psoriasis, and multiple sclerosis. According to Elaine Kang-Yum, a pharmacist and director of the Herb Watch Program at Long Island Poison Control Center at Winthrop University Hospital in Mineola, evening primrose oil can break down fatty deposits in the blood, and may lower cholesterol and blood pressure and thereby prevent heart disease. It also has hormonal properties.
Dr. Fred Pescatore, an internist in Manhattan who specializes in nutritional medicine, says evening primrose oil "works well in menopausal women or in estrogenic syndromes such as PMS, breast tenderness, menopausal changes, hot flashes and vaginal dryness." There are also reports of its use in treating dry eyes associated with Sjogren's syndrome, and a few nutritional deficiencies.
WHAT IS KNOWN:
The American Botanical Council reviewed 22 clinical studies of evening primrose oil, which included a total of 1,154 participants. All but six of the studies showed the oil has a positive effect in treating PMS, dermatological conditions, diabetic neuropathy and arthritis. It appears to be safe to use in children as well. "It has been used in high doses for eczema in children with apparent safety," says Mary Beth Augustine, an integrative medicine nutritionist at the Continuum Center for Health and Healing at Beth Israel Medical Center in Manhattan.
The Arthritis Foundation lists evening primrose oil as a way to relieve joint pain, stiffness and inflammation. According to ConsumerLab.com, studies have shown GLA to be useful in treating breast pain associated with the menstrual cycle.
Some lab and animal studies have suggested evening primrose oil may have anti-cancer activities as well, according to K. Simon Yeung, manager of the AboutHerbs website run by the Integrative Medicine Service at Memorial Sloan-Kettering Cancer Center in New York. In fact, one study which looked at evening primrose oil as an adjunct therapy to tamoxifen found it may decrease tumor formation. However, Yeung cautions, more data from human clinical trials are needed.
"I think of this as one of the safer, more evidence-based supplements that has been shown to have a very good safety profile with low toxicity," says Augustine.
Reported adverse effects include headache, mild nausea and abdominal bloating, but Kang-Yum says they are rare. Overdose symptoms include loose stools and abdominal pain.
Evening primrose oil has anti-clotting properties and may affect blood pressure, Kang-Yum says. It should not be used by people who take aspirin or a blood-thinning medicine like Coumadin, blood-pressure medications or cholesterol-lowering drugs. Because it acts as a natural estrogen, it should not be taken with herbs like ginseng or dong quai, which can have estrogenic properties.
There have been some reports that people with schizophrenia and/or who are on seizure medication should not take evening primrose oil because GLA may exacerbate temporal lobe epilepsy, but this effect has not been confirmed.
"By and large, the American public is deficient in the essential fatty acids," Augustine says. "Evening primrose oil is one of the best sources of gamma-linolenic acid." She says people should boost their intake of GLA by eating more flaxseed and hempseed.
When taken for medicinal uses, Augustine says evening primrose oil has benefits. However, people must be careful about how much they take and what they buy. Ask your health care provider about recommended doses for treatment, and buy from a reputable source that performs tests on its products, Pescatore advises. "You want to make sure there are no pesticides or herbicides. Any reputable supplement company will give you good pharmaceutical grade evening primrose oil."
Also keep in mind that products vary significantly in terms of the amounts
and ratios of various fatty acids. ConsumerLab.com advises that people
stay away from products claiming a "complex formula" or "blend" which do
not specifically state the amount of GLA.
Copyright © 2003, Newsday, Inc