Cold
pressed Evening Primrose Oil has a golden yellow color and
fresh nutty odor. It is obtained by expeller pressing of
the tiny black seeds. As the seeds contain only around 25%
oil and they are fairly expensive, Evening Primrose oil is
often obtained by solvent extraction as this method has a
much higher oil yield. Recently, Evening Primrose Oil has
received a great deal of attention because it contains the
rare EFA
g-linoleic
acid, which is found in only three other plant species.
Origin
American Indians used the native Evening Primrose seeds,
leaves and roots for centuries. The Pilgrims learned of
the plant and it was introduced to England in the 16th
Century by John Tradescant, gardener and herbalist to
Queen Elizabeth I, because of its reputation for promoting
healthy skin. The Evening Primrose has since flourished as
both an ornamental flower and a medical herb in Europe,
enjoying names such as "Beauty of the Night" in France and
"Virgin Night Candle" in Germany because its luminous,
four petaled yellow flowers open only in the evening.
Although still a rare crop, Evening Primrose is
increasingly grown in countries with a continental or
temperate climate, such as North West and Central Europe,
Canada, New Zealand and in particular, China.
Properties
Evening Primrose is rich in two very important
polyunsaturated fatty acids, as it contains over 70%
linoleic acid and about 10% of the rare
g-linoleic
acid.
In the
body g-linoleic
is directly derived from linoleic acid and metabolized
into autocoids, hormone-type substances which play key
roles in a wide range of physiological functions in the
body, especially in the skin.
Evening Primrose oil can be distinguished from
monounsaturated oils in that it does not act by occlusion
only, but is readily absorbed by the skin, where it exerts
its effect in two ways e.g. by reduction of the Trans
Epidermal Water Loss and by the formation of autocoids.
The linoleic acid is a very important building block in
the formation of the by-layer lipid membrane, whereby the
other fatty acid,
g-linoleic
acid not only enhances the penetration into the skin, but
also the restoration of the water barrier function of the
skin.
Furthermore,
g-linoleic
acid is a key precursor in the synthesis of autocoids. In
particular the skin is very sensitive to an imbalance of
the autocoids resulting with increasing deficiency of
linoleic acid., resp.
g-linoleic
acid, in the development of skin roughening and even skin
lesions. In a healthy person
g-linolenic acid
is formed from linoleic acid by an enzyme called delta-6
desaturase. However, the proper functioning of this enzyme
is often impaired by such common facts as age, stress,
diabetes etc. as of result of which insufficient
g-linoleic
acid and its metabolites are formed and skin disorders may
aoccur. Moreover the skin itself lacks this enzyme and
thus relies on a supply of
g-linoleic acid
and it deratives from the blood circulation. Thus it is
understandable that the skin is the first organ to suffer
in case of an EFA deficiency and can greatly benefit from
the topical application of Evening Primrose Oil.