Native Americans were the first to discover and utilize the delicate, flowering evening primrose plant for medicinal purposes. They applied it externally to promote wound healing and used it internally as a remedy for many types of infections. It was also valued as a sedative, pain killer, and diuretic. Evening primrose plants are still a common sight along stream beds and roadsides throughout North America. Today, research links the oil from evening primrose seeds with the prevention and treatment of many health conditions.

Tough healing power within the tiny seeds

The curative secret of evening primrose lies deep within the plant's tiny seeds. Oil from these seeds is a rich source of omega-6 fatty acids (or linoleic acid). Omega-6 fatty acids are one of the two essential fatty acids (EFAs) that the body must have, yet cannot synthesize itself. Consequently, dietary sources of omega-6 are required for overall good health.

Perhaps more important than the omega-6 fatty acids in evening primrose oil is another fatty acid that it contains: gamma-linolenic acid (GLA). Although the body can metabolize GLA from omega-6 fatty acids, it's tricky business. Many potential roadblocks can inhibit the creation of GLA, including alcohol, tobacco, stress, illness, increasing age, excessive levels of other dietary fats, and inadequate amounts of vitamins and minerals.

The beauty of evening primrose oil is that it provides the body with the GLA it needs, regardless of the presence of roadblocks. Once the GLA has made it into the system, the body is ready to do its real work: manufacture prostaglandins.

What's so special about prostaglandins?

Prostaglandins are hormone-like substances that regulate many body functions. To be blunt, they control every cell of the body on a second-by-second basis.

The clincher is that prostaglandins have a very short lifespan, which is why GLA and the other precursors used to create prostaglandins are needed in ready abundance to replenish supplies of this important body regulator.

For instance, the joint inflammation characteristic of rheumatoid arthritis is caused, in part, by the body's production of excessive amounts of the "wrong" kind of prostaglandins and not enough of the "right" kind. Supplements of evening primrose oil have been shown to boost production of the anti-inflammatory prostaglandins.

Researchers at the University of Massachusetts Medical Center reviewed clinical trials, animal experiments, and laboratory studies in which GLA was used as an arthritis treatment. The evidence showed that GLA-containing supplements, such as evening primrose oil, alleviated symptoms of morning stiffness, joint pain, and swelling in rheumatoid arthritis patients. An additional benefit of GLA supplements was a reduced reliance on arthritis medications, such as non-steroidal anti-inflammatory drugs (NSAIDs).

Other health benefits from evening primrose

Evening primrose oil, through its contribution to prostaglandin production, also helps lower cholesterol levels, inhibit clumping of blood platelets, and reduce blood pressure -- all of which stave off cardiovascular diseases. The metabolism of EFAs may be impaired in those suffering with diabetes, which in turn increases the risk of diabetic complications. Supplements of evening primrose oil have been show to prevent these common secondary conditions of diabetes.

Other health problems that may be alleviated by supplemental intake of evening primrose oil include cancer, by inhibiting the growth of malignant cells; atopic eczema, by normalizing levels of EFAs; and pre-eclampsia (a toxic condition developing in late pregnancy characterized by a sudden rise in blood pressure, excessive weight gain, and other symptoms), by increasing beneficial prostaglandins.