Hemp Seed Oil
Hemp Seed Oil the information we have been fed about Omega-6 for at least the last 10 years! Surely in their inflammatory state, eczema patients should have high arachidonic acid levels. Horrobin et al also remind us that this is not the first time this observation had been made, it is pointed out in the Horrobin study that for decades the same "oddity" has been observed. This "oddity" was then explained in terms of eczema having more to do with a delta-6-desaturase problem. In other words, the eczema was somehow linked to the fact that linoleic acid was not being converted to arachidonic acid fast enough! This inefficiency of delta-6-desaturase activity was "proven" when it was shown that giving pure GLA to patients, which is the next step along from linoleic acid and therefore bypasses delta-6-desaturase activity, actually did increase arachidonic acid levels but also decreased levels of the pro-inflammatory leukotriene eicosanoids which are ultimately derived from arachidonic acid (see below for more info on leukotrienes)! GLA had a positive influence on the eczema thanks to this effect in lowering the inflammatory eicosanoids even though arachidonic acid was raised. Here we cross over with the work of Surette ME et al 2003 who also looked at this question of the effect of GLA on arachidonic acid levels. Surette et al were particularly interested in asthma. Basically, their work showed exactly the same as Horrobin et al in that GLA given alone to patients led to an increase in a arachidonic acid, even though it was having an anti-inflammatory effect, by virtue of lowering the leukotriene levels. What is more, the Surette team take things further and discover that if Omega-3 fatty acids are given alongside the GLA (Omega-6) then the rise in arachidonic acid does not happen but the same antiinflammatory effect occurs! This has got to be the best case for BALANCE yet. In other words, to put it simply, if you take all types of essential fatty acids things work just fine! The implication here of course is that high levels of dietary linoleic acid is irrelevant to the inflammation because delta-6desaturase is designed to convert only small quantities and acts as a rate limiting step. I could extrapolate and hypothesise that this rate limiting effect of delta-6-desaturase is an in-built safety mechanism to stop excess production of arachidonic acid. In fact it is thought that the rate of conversion of linoleic acid to arachidonic acid is about 0.3%-0.6%. What's more, it would appear that arachidonic acid levels in the body do not change at all when linoleic acid levels reach 2% of daily calorie intake. Add to this the fact that mixed intake of Omega-3 and Omega-6 does not appear to affect the arachidonic acid levels at all, even if linoleic acid is in excess. This information by itself totally trashes the concept that high linoleic acid is bad for us and that we, in the western world, may be taking too much. We are back to balance! Another interesting point is that these teams observed that GLA levels in the body plateau within 7 days, once again backing up my observations of the speed at which these oils seem to get into eczema sufferers systems. Maybe the most important study done on this question of how linoleic acid levels are related to arachidonic acid levels was done by Retty BS et al 2011. This was basically an enormous review of the subject. The team looked at over four thousand papers on this subject and slowly whittled them down on the grounds of how reliable the data they contained were. The most important point of the review was that it concentrated on studies carried out on normal, healthy, human adults on an average western diet, no animals or cell cultures...real people. Their conclusions are simple: THERE IS NO SIGNIFICANT CHANGE IN ARACHIDONIC ACID LEVELS WITH VARYING LEVELS OF LINOLEIC ACID IN THE TYPICAL WESTERN DIET. Given the sheer volume of papers they started with I think it is safe to say that this question is now answered categorically. To quote some figures from their work, if you decreased linoleic acid levels by 90% in the average western diet there was no significant change in arachidonic acid levels; if you increased linoleic acid levels by 6 times in the average western diet there was no significant change in arachidonic acid levels. I could, if I wanted, extrapolate a little bit further here, and ask, so if the dietary intake of linoleic acid has nothing to do with arachidonic acid levels, does anything? The
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