Five weeks of supplementation with cetoleic acid-rich fish oil also led to significant improvements in insulin sensitivity and glucose levels. The oil used in the study is a natural oil from North Atlantic fish, naturally rich in LCMUFAs, with cetoleic acid as the predominant fatty acid.
The Norway-based researchers published the findings of their rat study in the British Journal of Nutrition and noted that cholesterol, insulin sensitivity and glucose levels are measures where standard fish oil with EPA/DHA has shown little or no effects.
“The two marine oils, that is, herring oil (containing cetoleic acid) and anchovy oil (virtually devoid of cetoleic acid), had remarkably different effects on the cholesterol metabolism in diabetic rats,” they wrote. “We conclude that consumption of a diet containing herring oil leads to a lower cholesterol concentration in a relevant rat model for T2D in humans.”
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. On the other hand, 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.
Study details
The new study, led by Professor Oddrun Anita Gudbrandsen, examined the effect of consuming fish oil with or without cetoleic acid for five weeks on cholesterol levels. The researchers used male Zucker Diabetic Sprague Dawley rats and fed them diets containing herring oil (HERO) or anchovy oil (ANCO) or a control diet with soybean oil. The herring oil is from Pelagia and refined by Epax.
The results showed that serum total cholesterol levels were 14% lower in the HERO group after five weeks, compared to both the ANCO and control groups.
“This finding in a rat model with type 2 diabetes induced by a Western diet is of great interest, especially since diabetes increases the risk for developing CHD in humans,” Professor Gudbrandsen said.
Indeed, previous research suggests that a reduction in total cholesterol concentration of 3% may reduce the risk of CHD by 15%.
The study was run by University of Bergen, Norway and funded by Norwegian Seafood research fund.
Omega-11
A couple of companies are commercializing cetoleic acid-rich fish oils, with Grøntvedt Biotech announcing it was developing such an oil in 2022 and then launching 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 & Omega-3 product a unique sensory quality which broadens the applications for usages from capsules to liquid formulations.
Earlier this year, Grøntvedt Biotech 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 the CETO3 EPA/DHA Pro-rata efficiency is 68% better than for the standard fish oil due to the bodies internal production of EPA/DHA, enhanced by omega-11.
Pelagia-Epax have also been exploring the potential health benefits of different cetoleic acid-rich fish oils, with a study published in Prostaglandins, Leukotrienes and Essential Fatty Acids indicating that their cetoleic acid-rich herring oil increased the Omega-3 Index similar to the same dose of omega-3 oil from anchovy and improved different measures of skin health.
Source: British Journal of Nutrition
Published online ahead of print, doi: 10.1017/S0007114524001454
“Intake of herring oil, but not of anchovy oil, resulted in a lower serum cholesterol concentration in male Zucker Diabetic Sprague Dawley rats"
Authors: E.V. Rimmen et al.
