Lab rats consuming krill oil were found to not have enlargement in their heart muscles or increase in the weight of the heart as non-supplemented animals, indicating that the krill oil may boost heart function, according to results published in BMC Lipids in Health and Disease .
The benefits of the omega-3-rich oil were only observed when krill was consumed prior to a heart attack, with no benefits observed if krill oil supplements started after the heart attack, report researchers from Oslo University Hospital, Norway and krill player Aker BioMarine Antarctic.
The study used Aker’s Superba Krill oil ingredient and the study was partly funded by the Norwegian company.
"The health benefits of krill oil have been previously revealed through numerous studies and clinical trials,” said Kjetil Berge, R&D director of Aker BioMarine Antarctic and co-author of the study.
“Previous studies have shown that krill oil increases the level of EPA and DHA in heart tissue, but this is the first study to indicate beneficial effects on a hard end-point like myocardial infarction.”
The shrimp-like Antarctic krill (Euphausia superba) is one of the globe’s most abundant species found in densities of up to 30,000 creatures in a cubic-meter of seawater. Rich in phospholipids and omega-3s, they are harvested to make omega-3 products.
The World Wildlife Fund (WWF) has proclaimed krill as the world’s largest under-exploited fishery.
The new study divided 53 male rats into three groups: A control group; a group given krill oil for seven weeks prior to induction of myocardial infarction; and a group given krill oil only after myocardial infarction induction.
Results showed that the animals given the krill oil before myocardial infarction had significant reduction in the growth of the heart (dilation of left ventricle), as well as lower heart and lung weights, compared with the control group.
The researchers also noted a reduction in the expression of certain genes involved in left ventricular stress, and inflammation.
Commenting on the potential mechanism, the researchers note that the omega-3 polyunsaturated fatty acids in the krill oil may replace saturated fatty acids in the heart muscle tissue, and this may lower the risk of coronary heart disease.
It is also possible, said the researchers, that the increase in EPA and DHA in the heart muscle increases the production of anti-inflammatory compounds, which benefit the heart.
“Although relatively few rats were studied, our findings may suggest that treatment with krill oil before myocardial infarction leads to attenuated left ventricular dilatation and hypertrophy in rats,” wrote the researchers.
“Future studies are needed to establish whether these beneficial effects are consequences of attenuated cardiac remodeling or reduction of myocardial infarction sizes,” wrote the researchers.
“Also, the molecular effects of krill oil on the heart are not yet clear and need to be examined further.”
Source: BMC Lipids in Health and Disease
2011, 10:245, doi:10.1186/1476-511X-10-245
“Krill oil attenuates left ventricular dilatation after myocardial infarction in rats”
Authors: L.E. Fosshaug, R.K. Berge, J.O. Beitnes, K. Berge, H. Vik, P. Aukrust, L. Gullestad, L.E. Vinge, E. Oie