Want to help lower the risk of chronic health problems associated with obesity, diabetes and heart disease? Look to your genes, says a new study led by University of Guelph researchers that links genetics, dietary fats and inflammation tied to these conditions.
The researchers hope their work will eventually help in testing for people predisposed to such diseases and in altering diet to prevent or treat chronic health problems.
Prof. David Mutch, Department of Human Health and Nutritional Sciences (HHNS), says this is the first study to relate dietary fatty acids and blood markers for disease inflammation to genetic variations in an enzyme called stearoyl-CoA desaturase 1 (SCD1).
He co-authored the study with researchers at Guelph, the University of Toronto and the Public Health Agency of Canada (PHAC). Their paper appears online in the December 2011 issue of Molecular Genetics and Metabolism.
The SCD1 enzyme converts saturated fats to monosaturated fats. It is associated with obesity, which is regarded as a low-grade inflammatory state, says Carolina Stryjecki, the paper’s lead author. She completed her master’s degree with Mutch last year and is now a staff scientist at PHAC in Toronto.
Says Stryjecki: “We want to see if SCD1 can influence that relationship and contribute to inflammation.”
Other Guelph researchers on the study were HHNS Prof. David Ma and graduate students Kaitlin Roke and Shannon Clarke.
The study found genetic differences in how SCD1 regulates metabolism of fatty acids in Asian and Caucasian young women. Mutch says more research is needed to learn about the enzyme’s role and how exactly it affects the relationship between fatty acids and inflammation. They’d also like to learn more about those differences in different ethnic groups.
“SCD1 is definitely involved, but is it a driver or a passenger?” he says, adding that “knockout” mice lacking the gene have been shown to resist diet- and genetic-induced obesity.
For this study, the researchers looked at blood samples from a cohort of young adults aged 20 to 29 in Toronto. (Those subjects, both male and female, were recruited by Ahmed El-Sohemy in U of T’s Department of Nutritional Sciences.)
SCD1 and other enzymes are key “metabolic hubs” that are known to be involved in metabolism of dietary components, but remain relatively unstudied at the genetic level, says Mutch.
In a study published earlier last year, he and his colleagues found a relationship between another enzyme called fatty acid desaturase 1 and the amount of polyunsaturated fatty acids in the blood. That genetic variation affects lipid metabolism differently between ethnic populations, he says, and perhaps affects risks of diseases in ethnic groups.
On their own dinner plates, Mutch and Stryjecki both follow the mantra of “everything in moderation.” But people with versions of genes that regulate fatty acid levels and that are associated with inflammation may benefit from altering their diet – the ultimate goal of these kinds of nutrigenomics studies, says the Guelph professor.
Stryjecki developed an interest in nutrigenomics while studying biology as an undergrad at Guelph. “It sounded cool,” she says. “I liked the aspect of looking at someone’s genome and saying, ‘Do they metabolize different nutrients differently?’”