PART 2: Introduction

I am often asked why I use Evening Primrose Oil (EPO) rather than Borage Oil (BO) as a source of GLA in Udo's Choice Oil Blend. BO is cheaper and contains more than twice as much GLA as an equal amount of EPO.

I could use BO in the blend if I wanted to do so. Why don't I?

For me, the quantity of GLA in oil and its price are not the primary deciding factors. Oil quality and the biological activity of its GLA should take priority. While BO is widely used in the marketplace as a source of GLA, a review of the research literature suggests that EPO may be preferable.

Let me share with you some of the research literature I have seen on EPA and BO.

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Physical Structure of the Oil

The oils from EPO and BO act different in the body because they differ in several ways:

• The GLA found in different seed oils is linked to the carbons of glycerol in different locations, forming different triglyceride (positional) isomers^1,2, which may differ in activity. GLA is found mainly on the outside carbons of glycerol in EPO, but on the middle carbon of glycerol in BO. This may affect the way in which the GLA functions in the body.
  
  
• GLA can be partnered with different fatty acids in a triglyceride molecule¹, that may also affect how GLA functions in the body.
  
  
• EPO contains far more omega-6 essential fatty acid (LA) than BO does. This difference may affect GLA function¹.
  
  
• The 'minor ingredients' in EPO are quite different from those in BO. These minor ingredients may affect and modify the activities of the GLA and the oil itself, and can yield dramatic differences in how the GLA molecule functions in the body¹.
  
  
• BO contains erucic acid (22:1) and even longer chain monounsaturates (24:1), which may affect the action of the oil. By the way, these long chain fatty acids can also be used to confirm whether an EPO product has been adulterated with cheaper BO³.

In other words, GLA does not act alone. Like EPO, BO does improve some conditions. But in other conditions, research shows that EPO works better than BO does, even though EPO contains less GLA. Some of that research follows.

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Research

Far more research has been done on EPO than on BO. A search of PubMed-Medline in July 2001 came up with 375 published studies on EPO. The same search engine listed only 71 studies done on BO.

According to studies, the health-benefiting activity of EPO in humans and animals is superior to that of BO in several respects:

• In a human study, EPO was shown to benefit health by reducing the production of TxB₂. TxB₂ increases the blood's clotting tendency, making it a risk factor for stroke, embolism, and heart attack. EPO's ability to lower TxB₂ makes EPO protective against these cardiovascular risk factors. BO, on the other hand, increased TxB₂, making clot formation leading to stroke, embolism, or heart attack more likely⁴.
  
  
• EPO decreased human platelet stickiness (aggregation). BO increased platelet stickiness, making a clot in an artery more likely, thereby increasing risk of a stroke, heart attack, or embolism occurring.
  
  
• In animals and humans, EPO elevates DGLA, from which prostaglandin E₁ (PGE₁), an eicosanoid hormone made from fats, which lowers cardiovascular risk factors⁵. DGLA also takes part in reactions that result in decreased inflammation⁵.
  
  
• In mice, EPO increased PGE₁ and Prostacyclin I₂ (PGI₂) production⁶. These two open up small blood vessels, increase blood supply to tissues, lower blood pressure, reduce inflammation pain and swelling, and reduce clot formation (platelet aggregation). BO reduced PGI₂ levels dramatically, lowering one of the body's main defenses against stroke or heart attack⁶.
  
  
• In rats with high blood pressure (spontaneously hypertensive), both EPO and BO can lower blood pressure, but weight for weight, EPO is more effective⁷.
  
  
• EPO reverses diabetic nerve damage in rats. BO has little or no effect⁸.

These research findings also appear in other publications. One of these is Principles and Practice of Phytotherapy: Modern Herbal Medicine. In that book, the following statements are found:

• "Although GLA has been found in higher concentrations from other sources, including borage oil, black currant oil and fungal lipids, there is currently less evidence to support their clinical efficacy compared to EPO."⁹
  
  
• "Evening primrose oil outperformed black currant oil, borage oil, and fungal oils in ameliorating nerve conduction velocity deficits in diabetic rats."⁹

Another is Dr. Andrew Weil's Integrative Medicine's onemedicine web site, which is aimed at medical professionals who need solid information on alternative treatments. Here is a quote from the Integrative Medicine web site:

• "GLA is available directly from evening primrose oil (7% to 10% GLA), black currant seed oil (15% to 20% GLA), borage oil (18% to 26% GLA), and fungal oil (23% to 26% GLA). GLA bioavailability may be related to the precise triacylglycerol composition. Although the GLA concentration in borage oil appears to be twice as high as in evening primrose oil, research has shown that the GLA effects, such as formation of prostaglandin E₁, are comparable for both on a gram-for-gram basis."¹⁰