HEMP ISSUE 14 v1.qxd:Jerkins feature.qxd
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linolenic acid (20% of the oil present) and also about 15% of the omega 9 fatty acid oleic acid. For horses in training where access to grazing is reduced, supplementation with omega-3-containing ingredients or feeds can be advantageous. Hemp also contains appreciable amounts of gamma-linolenic acid GLA (1-4% of total oil present), which is more commonly associated with evening primrose oil. In human nutrition, GLA is reputed to have anti-inflammatory properties and is associated with complementary use for eczema and pre-menstrual tension in women. Likewise, in horses GLA has previously featured in calming products and also those targeted at coat condition and skin health. Like most vegetable-derived oils, the stability of the constituent fatty acids in hemp is supported by its natural antioxidant content that consists predominantly of gamma-tocopherol, a natural form of vitamin E. The oil content of hemp can be extracted by a process known as cold-pressing, which
retains the integrity of the constituent fatty acids. Where the majority of the oil has been extracted from hemp seeds, the residue remaining is hemp flour or cake, which is often the material that finds its way into the animal feed sector. This material may be useful as a source of quality protein, but it also retains a reasonably high oil content. Tetrahydrocannabinol (THC) levels are generally very low in hemp Hemp technically belongs to the same family as marijuana, Cannabis sativa. However, apart from physically looking very different, hemp does not contain any appreciable levels of the psychoactive substance tetrahydrocannabinol (THC). The level of THC found in the varieties of hemp cultivated commercially is very low, typically less than 0.3% as opposed to the 7-20% in the psychoactive plant. The THC, which stimulates the nervous system, is predominantly found within the leaves, with very little present within the harvested seed, where the greatest nutritional value is found.
The varieties of hemp that can be grown under Home Office license within the UK or within the EU for human or animal consumption must legally contain THC levels below a threshold of 0.02% or 200mg/kg. However, there is no doubt that THC would be considered a prohibited substance under the rules of racing within EU member states. Despite the very low level of THC present in the seed and extracted oil, there have previously been some concerns relating to the presence of these minute quantities of THC in human hemp-based foodstuffs and the likelihood of ‘testing positive’ during work-based drug testing. Previously, individuals have cited their consumption of such foods as a defense against a positive employmentbased urine test for THC, where marijuana use is suspected. Studies were subsequently carried out to establish whether this was valid or not. An assessment of the effect of regular consumption of hemp containing foods on urinary levels of THC was undertaken in people in the USA. This study compared four doses of THC (ranging from 0.09 to 0.6 mg/day) as being representative of the typical levels found in hemp seed products and reflecting common consumption. Following 10 days of supplementation, in this study, only one urine sample of the 15 tested was reported as positive as it was found to be above the 50 ng/ml urine threshold. However, in a subsequent study, where the urine collection protocols were more rigorous but the intake of THC similar, a greater number of ‘positives’ were found, although a large amount of variation between individuals was noted. While it was concluded that it was unlikely that the regular consumption of hemp-containing foods would elicit a positive urine test above the reporting threshold, the situation with respect to athletic competition may be different. The rules of racing, for example within the member states of the European Horseracing Scientific Liaison Committee (UK, Ireland, France, Germany, Italy) would certainly consider THC to be a prohibited substance and as there is no published threshold for THC, where THC was present in urine a positive test would largely depend upon the sensitivity of the analytical protocols of the regulatory laboratories, which may well be very high. So while the level of THC in hemp seed or oil is likely to be extremely low, if present at all, the lack of information on the effect of regular feeding in horses currently acts as a cautionary barrier to its widespread use in racing. However, with the growing interest in hemp as a feed ingredient and the growth of the hemp industry, appropriate research could be undertaken to ease its passage into the equine feed sector. I ISSUE 14 TRAINERMAGAZINE.com 41