Evening Primrose 

Introduction:

     Generations of Native Americans and other groups have used the Evening Primrose plant, Oenothera biennis, as an herbal remedy for various ailments. They use a leaf extract for arthritis pain, hemorrhoids, bruises, and rashes and eat the boiled roots for general nutrition. This tall plant produces brilliant yellow 2.5 inch flowers that open one evening and wither during the next day, giving it its name.

      The oil popular today is an extract of the seeds. Modern science suggests that its benefit derives from its high concentration of the essential fatty acid linolenic acid and its derivative gamma-linoleic acid (16% concentration), precursors to the prostaglandins that modulate our immune response. The body turns them into dihomo-gamma-linolenic acid, which blocks arachidonic acid conversion to Leukotrienes. DGLA also is converted to series 1 prostaglandings which competitively inhibit the series two prostaglandins and series 4 leukotrienes responsible for increasing inflammation. Thus it putatively has a multi-pronged anti-inflammatory effect.  Otherwise put, Evening Primrose is believed to reduce the proteins in your body that lead to inflammation.  Supporters believe Evening Primrose decreases the severity of diseases such as inflammatory conditions such as Rheumatoid Arthritis and ameliorates conditions from Eczema to Premenstrual Syndrome.

Evidence:

Studies of the effects of gamma-linoleic acid on rheumatoid arthritis seem promising. Animal models show definitive evidence of decreased inflammation. One double-blind placebo controlled trial demonstrates some effect of gamma-linoleic acid on symptoms of RA with relapses after discontinuation (Belch). A 1993 trial using 1.4g GLA demonstrates a clinically significant reduction in joint tenderness vs placebo (Leventhal) Further trials are ongoing as the usage of alternative treatments become more widespread. A study on borage oil, another herb containing gamma-linoleic acid, demonstrates some efficacy for this product, although sufficient evidence is lacking. In sum, some sources suggest an effect for Evening Primrose, although there is no definitive proof.

Dosages:

1000mg Evening Primrose Oil three times a day provides 240mg gamma-linoleic acid, a standard dose for treatment of Rheumatoid arthritis. Some trials, however, are conducted at higher doses, and guidelines might change. Most sources suggest it takes 3-months to see effects, because that amount of time is necessary to experience the manifestations of decreased inflammation. It is important to keep in mind that this product, along with all alternative treatments is not FDA regulated.  For this reason, it is essential to always communicate with your physician and to purchase the products from a reputable company.

Side Effects:

This agent is generally quite well tolerated at pharmacologic doses. Some patients report diarrhea, headache, nausea, and skin rash. Patients with seizure disorders, those taking antipsychotic drugs, and those with bleeding disorders should not take this drug, as its active ingredient can worsen their condition. Pregnant and breastfeeding women should avoid this agent and any other drug not proven safe in their situation.  Any agent can interact with medications you may be on.  Always speak with your physician before starting any new herb or supplement. 

Authors:

Sanjiv Bajaj, A.B., University of Alabama-Birmingham School of Medicine, Birmingham, AL

Neil Chaterjee, M.D., New York-Presbyterian Hospital, The University Hospital of Columbia and Cornell, New York, NY

Web resources:

http://www.berkeleywellness.com/html/ds/dsEveningPrimrose.php

http://altnature.com/gallery/Evening_Primrose.htm

http://botanical.com/botanical/mgmh/p/primro70.html

http://www.umm.edu/altmed/ConsHerbs/EveningPrimrosech.html

http://www.umm.edu/altmed/ConsHerbs/EveningPrimrosech.html

Articles:

Belch JJ and Hill A. “Evening primrose oil and borage oil in rheumatologic conditions.” Am J Clin Nutr. 2000 Jan;71(1 Suppl):352S-6S

Leventhal LJ, Boyce EG, and Zurier RB. “Treatment of rheumatoid arthritis with gammalinolenic acid.” Ann Intern Med. 1993 Nov 1;119(9):867-73.

Joe LA and Hart LL. “Evening Primrose Oil in Rheumatoid Arthritis.” Ann Pharmacother. 1993 Dec;27(12):1475-7.

Belch JJ, Ansel D, Madhock R, O’Dowd A, and Sturrock RD. “Effects of altering dietary essential fatty acids on requirements for non-steroidal anti-inflammatory drugs in patients with rheumatoid arthritis: a double blind placebo controlled study.” Ann Rheum Dis. 1988 Feb;47(2):96-104.