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Essential Fatty Acid Status

Essential Fatty Acids

There are two essential fatty acid pathways: omega 3 and omega 6. The relationship between the omega 3, eicosapentaenoic acid (EPA) and the omega 6, arachidonic acid (AA) is particularly important as the ratio of these two fatty acids is an excellent marker of inflammation.

Adequate levels of omega 3 fatty acids, and docosahexaenoic acid (DHA) and EPA in particular, have proven protective against heart disease. In addition, a healthy ratio of AA to EPA has been associated with improvements in a variety of diseases like: rheumatoid arthritis, asthma and diabetes. Some cancers may also benefit from a lowered ratio of AA to EPA.

Some important facts regarding essential fatty acids:

  • the omega 6 pathway contains arachidonic acid (AA), which is a precursor to the inflammatory prostaglandin 2 cascade.
  • the omega 3 fatty acid pathway contains eicosapentaenoic acid (EPA). EPA and AA compete for the same enzyme systems: EPA to make Pg3, a vasodilatory, antiplatelet aggregation prostaglandin, and AA to make the inflammatory prostaglandins.
  • EPA represents omega 3 status and AA represents omega 6 status. Thus, inadequate omega 3 intake coupled with excessive dietary intake of omega 6 can result in an elevated AA to EPA ratio. Dr. Barry Sears, author of The Anti-Inflammation Zone calls this ratio the Silent Inflammation Profile, or SIP.
  • humans evolved on a diet of approximately 1:1 AA to EPA. The average North American diet consists of over 10 to 1 of AA to EPA. In other words, most people consume more than 10 times more inflammatory omega 6 fatty acids than they require.

An elevated ratio of AA to EPA increases risk of the following diseases:

Heart disease: According to the 1994 Lyon Heart Study, a 4 to 1 ratio in the diet (Mediterranean Diet) was associated with a 70% decrease in cardiovascular mortality post MI when compared to a 14 to 1 ratio consumed from the American Heart Association diet.

Lung cancer: A lowered ratio of omega 6 to omega 3 fatty acids is associated with reduced invasion potential of human lung cancer cells.

Breast cancer: Fatty acid levels in breast adipose tissue support the hypothesis that omega 6:omega 3 balance plays a role in breast cancer.

Colorectal cancer: A 2.5 to 1 ratio is associated with decreased colorectal cancer cell proliferation while a 4 to 1 ratio showed no benefit.

Asthma: A 10 to 1 ratio is associated with exacerbation of methylcholine induced asthma symptoms while a 5:1 ratio was associated with improved symptoms.

Diabetes: A 20 to 1 ratio is associated with increased incidence of diabetes whereas a 6 to 1 ratio is associated with decreased incidence of diabetes.

Rheumatoid arthritis: A 2 or 3:1 ratio is associated with a reduction in arthritis symptoms.

The research cited above supports the notion that measuring essential fatty acid status, and the ratio of AA to EPA in particular, is an excellent means of assessing health status in the absence of overt disease.

EFA: Clinical Considerations


Clinical Considerations

Total Omega3

Total omega 3 scores of greater than 7.2% by weight are associated with low risk of coronary heart disease.


EPA + DHA scores of > 4.6% by weight are associated with low risk of fatal ischemic heart disease.


DHA scores of more than 4.5% by weight are associated with low risk of coronary heart disease


Note that the enzymes lipoxygenase (LOX) and cyclooxygenase (COX) are needed to make nflammatory from AA as well as vasodilatory Pg3 from EPA. Therefore, when there is an excess of AA relative to EPA, more inflammatory prostaglandins are likely to be produced. This is the source of ”Silent Inflammation‘ that Dr. Barry Sears talks about in his book The Anti-Inflammation Zone. Conversely, when EPA is present in sufficient quantity, the LOX and COX enzymes are occupied making more heart healthy Pg3 rather than inflammatory.

Research indicates that humans evolved on a diet of approximately 1:1 AA to EPA, yet most North Americans have a ratio of more than 10 to 1. Dr. Sears states: —it is the ratio of AA to EPA in the blood that provides the most precise marker of silent inflammation …. I cannot emphasize enough the importance of the [ratio of AA to EPA]“ Dr. Sears refers to measurement of the AA:EPA ratio as the —SIP“, which stands for Silent Inflammation Profile.

Research on the AA to EPA ratio continues to highlight the importance of maintaining a low ratio. Competition by AA and EPA for the same enzymes means that excess AA results in the production of more inflammatory prostaglandins. And, excess inflammation, as measured by the ratio of AA to EPA, has been definitely correlated with a number of diseases. Thus, a simple test of essential fatty acid status gives us an excellent means of assessing health status in the absence of overt disease.


good quality fish oil supplement restores the balance between Omega 3 and Omega 6. Look for products that meet International Fish Oil Standards (IFOS). Amounts from 2 to greater than 10 grams may be required. Testing can determine whether healthy ratios and percentages have been achieved.

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