Lipid profile of mice fed a high‐fat diet supplemented with a wax ester‐rich marine oil

Abstract

Oil extracted from the marine copepod Calanus finmarchicus contains the long chain omega-3 fatty acids eicosapentaenoic acid and DHA in addition to stearidonic acid (18:4n-3). Unlike other marine lipids, the fatty acids in this oil are esterified with long chain fatty alcohols as wax esters. The aim of this study was to examine the fate of the wax esters in oil from C. finmarchicus when given as a 2% supplement in a high fat diet to C57BL/6J mice for 11 weeks. The study confirmed that feeding mice a high fat diet supplemented with a small amount of oil containing wax esters reduced the body weight gain. During digestion, wax esters were hydrolyzed and the fatty acids absorbed since the fatty acid composition of the adipose tissue and liver reflected the enrichment with the Calanus oil. The composition of the liver lipids demonstrated elongation and desaturation of the C18 omega-3 fatty acids from the feed and accumulation of longer chained omega-3 fatty acids. Elevated levels of FFA and FAOH in the feces suggest that the absorption process, not the hydrolysis, could be a rate limiting step in utilization of small amounts of wax esters included in high fat diets in mice.Practical applications: The limited amount of available fish oil has led to extensive search for alternative sources of long-chain PUFA. One suggestion is to harvest at lower trophic levels, like small crustaceans, which may be abundantly present in the oceans. In this investigation, we have studied the effects of including the astaxanthin-rich oil from the marine copepod C. finmarchicus in a high fat diet in mice. This oil is different from other marine oils since most of the fatty acids are esterified to long-chain fatty alcohols, not in TAG, and that stearidonic acid is the major omega-3 fatty acid present. The results provide knowledge and understanding of aspects related to digestion and possible physiological effects of including small amounts of marine wax esters in diets.Abbreviations: ALA, alpha linolenic acid; þCal, inclusion of 2% calanus oil; DPA, docosapentaenoic acid; EE, ethyl ester; EPA, eicosapentaenoic acid; eWat, epididymal white adipose tissue; FAOH, fatty alcohol; FFA, free fatty acid; HFD, high fat diet; HPLC-ELSD, HPLC coupled with an evaporative light scattering detector; LC-PUFA, long-chain PUFA; pWat, perirenal white adipose tissue; SDA, stearidonic acid; WE, wax ester 1718Eur.

Mesopelagic Species and Their Potential Contribution to Food and Feed Security—A Case Study from Norway

“…Compared to triacylglycerol, wax esters are considered to be less bioaccessible due to poorer digestibility in both mammals [74] and Atlantic salmon [75]. However, fatty alcohols may be oxidized [76] and hydrolyzed [77] in the digestive tract of rodents and can therefore not completely be ignored as a nutrient. It is not known if it is the digestion, absorption, elongation or oxidation of wax esters that may regulate their nutritional value [77].…”

“…However, fatty alcohols may be oxidized [76] and hydrolyzed [77] in the digestive tract of rodents and can therefore not completely be ignored as a nutrient. It is not known if it is the digestion, absorption, elongation or oxidation of wax esters that may regulate their nutritional value [77].…”

Effect of Calanus Oil Supplementation and 16 Week Exercise Program on Selected Fitness Parameters in Older Women

“…On the other hand, the safety of n-3 PUFA supplementation in healthy individuals has been acknowledged by relevant authorities, such as EFSA (supplemental intakes of EPA and DHA combined at doses of up to 5g/day do not raise concerns for adults) [25]. Because a combination of exercise and n-3 PUFA supplementation has shown some beneficial effects on health and fitness [16,18,19], we focused on a novel class of n-PUFA supplementation-Calanus Oil produced from the marine copepod Calanus finmarchicus [26]. Calanus oil contains a combination of fatty acids, fatty alcohols, and wax esters, and is possibly the best alternative to fish oil whose production cannot keep pace with demand from the growing market [27].…”

Possible Health Effects of a Wax Ester Rich Marine Oil

“…This novel marine oil is relatively low in EPA and DHA compared to other marine oils (6% and 4% respectively), but is relatively rich in SDA (7%), see Table 2 (Pedersen et al, 2014a;Cook et al, 2016b). The main fatty alcohols present are the equivalents of the dominant LC-MUFA in the oil, namely the monounsaturated long-chain fatty alcohols eicosenol (20:1n-9) and docosenol (22:1n-11) (Pedersen et al, 2014a). In Table 2, it can be seen that in oil in C. finmarchicus the abundance of EPA and DHA is highest in the phospholipids.…”

“…But this remains, however, controversial (Salem and Kuratko, 2014). Phospholipids are, however, not detected in the commercial Calanus ® Oil (Pedersen et al, 2014a) probably due to endogenous enzymatic hydrolysis (Vang et al, 2013). The oil has also been reported to contain about 1500 ppm astaxanthin (Pedersen et al, 2014b).…”