(Oenothera Biennis)
Also called: Evening star.
Habitat: A native of North America, evening primrose is now widely naturalised across Europe and is commonly found in hedgerows as a garden escapee. Most seeds for oil production arc grown commercially.
Part used: seed oil
Actions: Alterative, hormone regulator, source of essential fatty acids
Medicinal Uses: Atopic eczema, fatty acid deficiencies
(especially gammalinolenic acid, or GLA), premenstrual tension.
The leaves
were traditionally used for asthma and digestive disorders.
The seeds are
rich in an essential fatty acid called gamma-linolenic acid (GLA) that is vital
for good health.
GLA is a building block for various prostaglandins hormone-like chemicals
vital for a number of bodily systems.
A normal, healthy metabolism will convert
commonly occurring cis-linoleic acid (found in leafy vegetables and seed
oils) into GLA, but this process can be affected by poor diet and high cholesterol
levels.
Some people are also unable to complete this metabolic
pathway, and this has been linked to disorders such as chronic
psoriasis and rheumatoid arthritis.
Typically evening primrose
oil contains around 9% GLA, although in recent years plant breeders have
worked hard to develop strains that will yield even more.
GLA is also reputed
to ease menstrual and menopausal problems, strengthen the circulatory system,
combat certain sorts of eczema and boost the immune system.
It can ease irritable bowel syndrome
where symptoms are associated with the menstrual cycle.
In clinical trials
dosages of 3-5 g a day have been commonplace, although for general use most
suppliers recommend 500-1000 mg.
The oil can also be used neat on the skin
for eczema and similar problems.
Because the oil also helps to normalise
liver function it can be useful to counter the symptoms of a hangover on "the
morning after'.
There has been a massive growth in sales and the plant has become
a major cash crop in many parts of the world.
In the 1980s GLA was also
found in borage and blackcurrant seed oils.
Forms available: Capsules, expressed oil, in skin preparations
and cosmetics.
Licensed evening primrose oil products are available and, in the UK, can
be prescribed for skin problems under the NHS.
Caution: In clinical studies less than 2 per cent of people
taking the herb for long periods noted side effects such as nausea, abdominal
discomfort and headache.
