Ten weeks of supplementation with the cetoleic acid-rich fish oil also exerted anti-inflammatory activity and mitochondrial activity, according to findings published in Frontiers in Nutrition.
“We demonstrated that CETO3 herring oil administration to rats reduced risk factors for cardiometabolic syndrome by lowering plasma lipids, including TG [triglyceride] and LDL [cholesterol] and total FAs [fatty acids], possibly mediated by peroxisomal and mitochondrial FA oxidation,” wrote the authors, led by Camilla Nundal from the Western Norway University of Applied Sciences in Bergen.
“However, given that the CETO3 herring oil also increased n-3 PUFAs and both hepatic and plasma levels of EPA and DHA, the observed benefits, including potential effects on the FA anti-inflammatory index, may not be solely due to MUFAs of n-11 and n-9 origin.”
Fish oil
The majority of the fish oil used for human nutrition is derived from anchovies and sardines because of the naturally high concentrations of EPA and DHA omega-3s. These are long-chain polyunsaturated fatty acids, or LC-PUFAs. North Atlantic fish like herring and mackerel have lower EPA and DHA concentrations but high levels of long-chain monounsaturated fatty acids (LC-MUFAs).
Cetoleic acid is the most abundant LC-MUFA, representing between 10% to 22% of the overall LC-MUFA content, followed by gadoleic acid and gondoic acid, depending on the type of fish.
A couple of companies are now commercializing cetoleic acid-rich fish oils. Grøntvedt Biotech announced it was developing such an oil in 2022 and launched it in 2023 under the brand name CETO3.
CETO3 is produced by immediately processing fresh fish to oil in less than 30 minutes at the company’s plant in Uthaug, Norway. According to Grøntvedt, this gives the CETO3 omega-11 and omega-3 product a unique sensory quality which broadens the applications for usages from capsules to liquid formulations.
Last year, Grøntvedt published its omega-3 index study, conducted with CET03 by Mike Wakeman, a researcher from University of Sunderland, which found that CETO3 omega-11 stimulated the body’s own production of EPA/DHA significantly, compared to the fish oil group. The published study showed that the CETO3 EPA/DHA pro-rata efficiency is 68% better than that of the standard fish oil due to the bodies internal production of EPA/DHA, enhanced by omega-11.
Commenting on the new study, Henrik Traaholt, CCO at Grontvedt Biotech AS, told NutraIngredients that the research focused on CETO3’s omega-11 ability to lower cholesterol—a health benefits that distinguishes it from traditional omega-3s.
“We also saw a very good anti-inflammatory effect and an effect on mitochondria, which is very interesting especially for longevity products,” he said.
“The anti-inflammatory effect we see is also beneficial for prevention of atherosclerosis. Further, a 3% reduction of cholesterol alone can reduce the cardiovascular risk by 15%. The effect we saw in this pre-clinical study using CETO3 omega-11 fish oil showed that CETO3 reduced total cholesterol by 41%, LDL Cholesterol by 45%, and total triglycerides by 55%. At the same time, the levels of HDL cholesterol are maintained.”
“We are only scratching the surface with health effects of omega-11,” Traaholt added.
Study details
Nundal and her co-workers fed lab rats low-fat diets supplemented with either CETO3 oil (5%) or soy oil for 10 weeks. The results showed that animals in the CETO3 group had 58% lower plasma levels of total fat in addition to the significant reductions in triglycerides, total cholesterol and LDL cholesterol. A 46% increase in the ratio of HDL to LDL cholesterol was also recorded.
CETO3 supplementation was also associated with increases in liver and plasma levels of long-chain omega-3, omega-9 and omega-11 MUFAs, including C22:1n-11, and a decrease in omega-6 fatty acid accumulation, the researchers reported.
“This enriched monounsaturated herring oil lowered total FAs in plasma, accompanied by FA profile changes in both plasma and liver suggesting a possible increase in anti-inflammatory activity,” they wrote.
“The FA anti-inflammatory index is related to increased hepatic and plasma content of EPA and DHA and the decrease in arachidonic acid, which was also observed in our study and has been associated with higher anti-inflammatory activity in humans, thereby potentially reducing inflammatory processes within the vessel wall—a contributing factor in atherosclerosis.”
Traaholt previewed that the company is preparing a clinical trial to explore the potential benefits in humans, while the Norwegian Seafoods research fund is also investing in clinical trials on omega-11/cetoleic acid.
“We have already done a pilot clinical trial on CETO3, so good documentation on health benefits on omega-11/cetoleic acid is on its way,” Traaholt said. “The Norwegian seafood research fund invests into science to build the documentation on cetoleic acid for the whole pelagic industry in Norway.”
Consumer education
While consumer awareness of omega-3s is high, awareness of omega-11s is low, and Grøntvedt is working with brands to educate consumers on the health benefits.
“We had the first consumer product out in 2023 in the European Union, now we have consumer products in Asia and the U.S. market,” Traaholt said, noting that the U.S. launch was a collaboration with The Vitamin Shoppe.
“CETO3 have received a lot of interest from innovative “early mover” brands as the early science is very promising,” he said. “CETO3 education is not only on the health effects on CETO3 omega-11 but also on the consumers benefit as there is no fishy smell, taste and no fishy reflux which widens the applications of CETO3 in different applications like liquid or capsules.”
Source: Frontier in Nutrition, Volume 12, doi: 10.3389/fnut.2025.1611166. “Herring oil rich in long-chain monounsaturated fatty acid (C22: 1n-11) lowers plasma lipids and modulates fatty acid composition. oxidation, and inflammation in rats”. Authors: C.H. Nundal, et al.
