Genetic background can affect the metabolism of essential fatty acids. Essential fatty acids are polyunsaturated fatty acids that are required for many important biological processes in the body, including the production of cell membranes, the regulation of inflammation, and the formation of various hormones. These fatty acids cannot be synthesized by the body and must be obtained from the diet.
A recent study from the University of Eastern Finland found that genetic background influences the metabolism of the essential polyunsaturated fatty acids alpha-linolenic acid and linoleic acid. Supplementing the diet with camelina oil rich in alpha-linolenic acid or sunflower oil rich in linoleic acid altered the concentrations of these fatty acid metabolites in the body; however, the changes were dependent on the FADS1 genotype of the study participants. The study was conducted among carriers of two different FADS1 genotypes.
“In only one of the genotypes studied, camelina oil increased the plasma concentration of eicosapentaenoic acid produced from alpha-linolenic acid,” says researcher and first author Topi Meuronen of the University of Eastern Finland.
Diet and genes have both been found to influence the concentrations of various fatty acids in the body. The FADS1 gene regulates polyunsaturated fatty acid metabolism, and the FADS1 genotype has previously been linked to glucose and lipid metabolism disorders, as well as the risk of type 2 diabetes.
Our research design, i.e., recruiting subjects on the basis of their genetic background, has proven effective in investigating the interactions between diet and genes.
Postdoctoral Researcher Maria Lankinen
Linoleic acid and alpha-linolenic acid are essential fatty acids that the human body does not produce, so they must be obtained from food. Linoleic acid is the most common omega-6 fatty acid in the diet. Alpha-linolenic acid, on the other hand, is a member of the omega-3 fatty acid family. Vegetable oils, seeds, and nuts contain varying concentrations of both. Sunflower oil is particularly high in linoleic acid among vegetable oils. Camelina and linseed oils, on the other hand, contain high levels of alpha-linolenic acid.
High intake and plasma concentration of linoleic acid has been associated with, e.g., a lower risk of type 2 diabetes and cardiovascular disease, but the association of alpha-linolenic acid remains unclear. As metabolites of linoleic acid and alpha-linolenic acid, the body produces lipid mediators which are important, but some of them also pro-inflammatory.
The researchers wanted to see if rs174550 point mutations in the FADS1 gene changed the effect of alpha-linolenic acid and linoleic acid on the composition of fatty acids in plasma and the concentrations of polyunsaturated fatty acid-derived lipid mediators. Carriers of two different FADS1 genotypes were recruited from the Metabolic Syndrome in Men (METSIM) study. For eight weeks, they supplemented their diet with 30-50 mL of camelina oil or sunflower oil daily.
“Our research design, i.e., recruiting subjects on the basis of their genetic background, has proven effective in investigating the interactions between diet and genes,” Postdoctoral Researcher Maria Lankinen of the University of Eastern Finland says.
For example, the body can produce eicosapentaenoic acid from alpha-linolenic acid and arachidonic acid from linoleic acid. These long chain fatty acids and the lipid mediators they produce are involved in many bodily functions, including inflammatory response and vascular function.
According to the findings, the FADS1 genotype influences how efficiently essential fatty acids are converted to arachidonic acid and eicosapentaenoic acid. The FADS1 genotype influenced the concentrations of metabolites derived from it as well.
The use of camelina oil rich in alpha-linolenic acid increased the concentration of eicosapentaenoic acid and lipid mediators derived from it in only one of the genotypes studied. In contrast, the use of sunflower oil rich in linoleic acid did not increase the concentration of arachidonic acid or its derived lipid mediators in carriers of either genotype.
“The changes in plasma eicosapentaenoic acid concentrations we observed were similar to those observed in our previous study, in which people ate fatty fish containing eicosapentaenoic acid. An intriguing finding was that when camelina oil was used, the changes only occurred in one of the genotypes studied “Meuronen adds.
According to the researchers, the findings raise the question of whether it is possible to provide increasingly personalized guidelines for alpha-linolenic and linoleic acid intake. However, more research is required.
