Fish oil supplements reveal their potential to protect against metabolic changes.
A high-fat diet comes with a broad selection of negative health consequences.
As researchers delve into the science behind these changes, a number of specific pathways have been found to be important.
An intricate web of chemical players conspire to generate the metabolic disorders caused by a high-fat diet. Some of the most important molecules and pathways include:
- Adiponectin - which regulates glucose levels and fatty acid breakdown
- Adipokines - a cytokine (cellular messenger) produced in adipose tissue
- Interleukin-6 - a cytokine involved in inflammation
- Tumor necrosis factor-alpha - a cytokine involved in inflammation
- De novo lipogenesis - a process that converts excess carbohydrate into fatty acids
- Lipolysis - the breakdown of fats to produce fatty acids.
The power of fish oil
Over recent years, fish oil has been heralded as a panacea for all ills; claims have been made regarding its ability to induce weight loss, increase fertility, improve skin health, and increase energy. Not all of its claims are backed by rigorous research, but its ability to modify metabolic pathways is gaining more evidence.
Fish oil is high in long-chain omega-3 polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexaenoic acid; these have long been known to improve insulin sensitivity and to have potent anti-inflammatory, hypolipidemic (lipid-lowering), and body weight reducing effects.
A team of researchers from the University of São Paulo, Brazil, set out to investigate how fish oil supplementation might influence the metabolism of mice fed on a high-fat diet.
The researchers fed mice fish oil supplements for 4 weeks before starting them on a diet that included high levels of both fat and fish oil.
Once the diet was completed, they collected and analyzed body fat samples from the mice. The samples were compared with fat samples from mice that had received a high-fat diet but no fish oil.
Fish oil and metabolic change
The team measured a number of factors that have an influence over metabolism, such as insulin resistance and fat deposits from different parts of the body.
As expected, the high-fat diet caused significant changes in a number of pathways; these included glucose uptake and secretion of adiponectin, tumor necrosis factor-alpha, interleukin-6, lipolysis, de novo lipogenesis, and secretion of pro-inflammatory cytokines.
This range of metabolic alterations, however, did not arise in the mice that received the fish oil supplementation. In other words, negative metabolic effects produced by high-fat intake were halted by fish oil.
The team was led by Prof. Maria Isabel Alonso-Vale, an assistant professor in the Department of Biological Sciences.
"'Our research suggests that fish oil supplements may be used in addition to other strategies as a preventative measure for insulin resistance and obesity."
Prof. Maria Isabel Alonso-Vale, lead investigator
The current study was carried out on a mouse model; as such, before the theory can be confirmed, it must be tested on human subjects. As Prof. Alonso-Vale continues: "More research will need to be done so we can have a better understanding of the effect of fish oil in humans."
The findings are intriguing and will, no doubt, attract follow-up investigations. Effective pharmacological interventions for metabolic disorders using fish oil extracts could be just around the corner.