“Our research showed that essential dietary fats are important players in the regulation of whole-body [stable glucose levels] and that this may stem partly from the regulation of the skeletal muscle secretome,” one of the leading authors of the study, Dr. David M. Mutch, told NutraIngredients-USA.
“Prior to our study, it was unknown if essential dietary fats could regulate the skeletal muscle secretome,” he added.
Dr. Mutch is an associate professor of human health and nutritional sciences at the University of Guelph in Canada. This paper, which he co-authored, was published online in the journal Physiological Genomics earlier this month.
In the paper, the researchers reported that both obesity-induced rat groups supplemented with alpha-linoleic-acid (ALA, an omega-3) and linoleic acid (LA, an omega-6) had lower glucose levels and better glucose tolerance compared to the obesity-induced control group after 12-weeks of intervention.
Significance: ‘People don't necessarily need to change their dietary behaviors to consume more foods rich in ALA and LA’
As Dr. Mutch explained, obesity is a complex metabolic disease that affects the function of tissues all around the body. It is commonly linked to insulin resistance, “which consequently disrupts whole-body glucose homeostasis.”
“Understanding how obesity influences global skeletal muscle gene expression will lead to the identification of new gene targets to develop therapies to address the various complications associated with excess body weight, such as insulin resistance, dyslipidemia, inflammation, and so forth,” he said.
He added that this current investigation showed that essential dietary fats can regulate skeletal muscle gene expression, albeit to a lesser extent than obesity.
“In some instances, ALA and LA were able to restore skeletal muscle gene expression to the levels seen in lean rats. Identifying dietary factors that influence skeletal muscle gene expression will provide an alternative approach to pharmaceuticals when it comes to addressing and preventing obesity-related complications,” he said.
“What makes our work interesting is that essential dietary fats were supplemented in the diet fed to rats. This suggests that people don't necessarily need to change their dietary behaviors to consume more foods rich in ALA and LA, but that a dietary supplementation approach could be beneficial in itself.”
In this study, the researchers used safflower oil for the LA supplement and flaxseed oil for the ALA. A popular source of ALA in food is the chia seed, while a more novel source used in some dietary supplements is Ahiflower oil.
Of course, results of this study on rats can’t simply be translated to human dietary recommendations. “Ultimately, more work is needed, but our research provides a solid foundation to continue this line of investigation,” he said.
What’s next?
While the study showed that essential dietary fats are capable of regulating the skeletal muscle secretome, “an important caveat is that our research investigated gene expression and, to a limited extent, protein secretion,” Dr. Mutch explained.
“Gene expression is useful to study, but the next step is to examine protein secretion from isolated muscle. Showing changes in protein secretion will provide even stronger evidence regarding the roles of ALA and LA on skeletal muscle.”
The study was supported by a grant from the Ontario Ministry of Agriculture, Food and Rural Affairs.
Source: Physiological genomics
Published online, https://doi.org/10.1152/physiolgenomics.00038.2018
“Alpha-linolenic acid and linoleic acid differentially regulate the skeletal muscle secretome of obese Zucker rats”
AuthorsL Alex Rajna, Heather Gibling, Ousseynou Sarr, Sarthak Matravadia, Graham P. Holloway, and David M. Mutch