Omega-3 / omega-6 ratio:why the right balance is crucial
Changes in food processing methods, diet and lifestyle over the past century have dramatically decreased our intake of omega-3, and increased our intake of short-chain omega-6 (mainly in the form of vegetable oils, which should be replaced with olive oil). It is absolutely vital to have the correct balance; a significant excess of one type over the other can have a detrimental impact upon health. The ideal ratio of omega-6 to omega-3 being in the region of 2:1, the average diet is now quite significantly out of balance at an average of approximately 25:1. So why has this happened?
Whilst our ancestors grew up on a diet that had a reasonably balanced omega-3:omega-6 ratio, Westernisation has changed the way we eat which has had dramatic effects on this balance. Indeed, the consumption of meat from land-based animals fed grains high in omega-6 fatty acids and increased use of vegetable oils such as corn, sunflower and safflower has led to a rise in omega-6 fatty acids intakes in the UK, whilst omega-3 intake has declined. The subsequent rise in the ratio of dietary intake of omega-6 to omega-3 fatty acids has been suggested to have negative implications for a wide range of health conditions including cardiovascular, inflammatory and autoimmune disorders due to an imbalance of eicosanoid derivatives. Furthermore the introduction of food processing and increased consumption of both saturated and trans fats has affected this ratio further.
The omega-3 and omega-6 families share and compete for the enzymes which are involved in converting short-chain fatty acids (LA and ALA) to long-chain fatty acids (DGLA, AA, EPA and DHA). Whichever family dominates in our diet will ‘hog’ this pool of enzymes and therefore affect the type of eicosanoid that is produced (inflammatory vs anti-inflammatory). What this means is that if a diet is high in omega-6 fatty acids but low in omega-3, then the enzymes will generally be used up by the omega-6 family through the conversion of LA to AA, leaving very little to convert ALA to EPA. The result of this is that the omega-6 family will give rise to inflammatory products, which will increase the risk of degenerative diseases including cardiovascular, inflammatory and autoimmune disorders.
How do I know if I have low omega-3 levels?
There are a number of physical signs which indicate a fatty acid deficiency and these are listed below:
- Excessive thirst, frequent urination
- Rough or dry ‘bumpy’ skin
- Dry, dull or ‘lifeless’ hair, dandruff
- Soft or brittle nails
- Sleep problems (especially difficulties in settling at night and waking in the morning)
- Attentional problems (distractibility, poor concentration and difficulties in working memory)
- Emotional sensitivity (such as depression, excessive mood swings or undue anxiety)
Omega-6 family: inflammatory or anti-inflammatory?
If, as we’ve said, our diets are high in omega-6 then why would we formulate our products to include them? The omega-6 issue can indeed appear to be confusing. Many articles on the subject try to simplify this matter, but in doing so end up giving misleading information. The fact is that the omega-6 pathway can give rise to both inflammatory and anti-inflammatory products.
The omega-6 fatty acid GLA is converted to DGLA and it is here that this pathway splits. DGLA can be directly converted to series-1 prostaglandins and series-1 thromboxanes, both of which are anti-inflammatory. For the pathway to veer this way there must adequate omega-3 in the diet. If there is a shortage of omega-3, the enzyme delta-5 desaturase will choose to convert DGLA into AA. AA is the precursor to the series-2 prostaglandins, series-2 thromboxanes and series-4 leukotrienes, all of which are inflammatory. We can influence which type of eicosanoids are produced, however. If we introduce omega-3 into the diet, then delta-5 desaturase favours this pathway and so becomes less available for the conversion of DGLA to AA, instead allowing DGLA to go down the anti-inflammatory route. By combining GLA with EPA we now get two different routes to the production of anti-inflammatory products – thus our formulations have a synergistic effect and enhance the benefits of these fatty acids.
How does EPA actually work?
EPA works in several different ways. Firstly, it is the precursor to the series-3 prostaglandins, series-3 thromboxanes and series-5 leukotrienes, all of which have anti-inflammatory roles. Secondly, when we consume EPA it competes with AA for uptake into cell membranes and can therefore lower the amount of AA in membranes by literally ‘taking up all the room’. When there is less AA there is a reduced capacity for it to produce inflammatory products. Finally, in order for AA to be converted into inflammatory products it must be converted by the enzyme cyclooxygenase. EPA also utilises this enzyme and if EPA levels are increased in the diet, it attracts this enzyme away from AA to EPA – again giving rise to anti-inflammatory products instead of inflammatory ones.