Rancid oils have health effect

How decisive is the quality of omega-3 in dietary supplements for getting positive health effects? Nofima has tested both high quality oils and rancid oils on human and fish cell cultures.

This article was last updated more than two years ago.

It has already been established that Omega-3 has extremely favourable effects on health. The leading sources are fatty fish or dietary supplements. But little is known about how important the actual quality of the dietary supplement is for the favourable health effect.

Bente Ruyter from Nofima has headed the research, which was commissioned by the RUBIN Foundation.

“We have used established human and fish cell systems and studied how health markers in the cells react when they are exposed to rancid oils. We are seeing effects on many health-related factors,” says Ruyter.

Good oils inhibit cancer development

In human cells we see that good oils to a greater extent inhibit the development of cancer cells and the expression of inflammation markers than is the case with rancid oils.

“The results from the cell studies provide indications about which substances can be of significance for humans, but the degree of influence is unclear,” says Ruyter.

In fish cells rancid oils led to increased expression of inflammation markers and increased cell membrane damage. They also influenced the cells’ own antioxidant system.

Important for human health?

“Previous comparative studies point to the fact that our cell system is extremely good models for the organism they come from,” says Ruyter. “However, it’s too early to say that the effects we have found at cell level can be transferred to humans and fish.”

Consequently, more comprehensive human studies are required in order to determine whether intake of rancid marine oils is of significance for our health. Trials are planned to test various oil qualities on relevant mammals and humans to confirm or invalidate the finds in the cells.

“It is important that people continue to take omega-3 supplements if they do not receive enough through intake of fatty fish,” emphasises Ruyter.

Nofima and its collaboration partners in research and industry have submitted an application to the Research Council of Norway about the establishment of a Centre for Research-based Innovation for marine oils.

The project report “Lite oksiderte omega-3 oljer og potensielle helsefordeler” (Little oxidised omega-3 oils and potential health benefits) is attached in PDF format (in Norwegian language only).

 Nutrition and feed technology  

Related content