A recent study from the University of Eastern Finland showed that genetic background has an influence on the metabolism of essential polyunsaturated fatty acids, alpha-linolenic acid and linoleic acid.
Supplementing the diet with camelina oil, which is rich in alpha-linolenic acid, or with sunflower oil, which is rich in linoleic acid, altered the concentrations of metabolites of these fatty acids in the body; However, the changes were dependent on the study participants FADS1 Genotype. The study was conducted between two different pregnant women FADS1 Genotypes.
“Camelina oil increased the plasma concentration of eicosapentaenoic acid produced from alpha-linolenic acid in only one of the genotypes studied,” says researcher and first author Tobi Merunen from the University of Eastern Finland.
It was found that both diet and genetics have an effect on the concentrations of various fatty acids in the body. The FADS1 The gene regulates the metabolism of polyunsaturated fatty acids, and FADS1 The genotype has been previously associated with disorders of glucose and lipid metabolism, and with a risk of developing type 2 diabetes.
Linoleic acid and alpha-linolenic acid are essential fatty acids that are not produced by the human body, that is, they must be obtained from food. Linoleic acid is the most common dietary fatty acid in the omega-6 family. On the other hand, alpha-linolenic acid belongs to the omega-3 fatty acid family. Various concentrations of both are found in vegetable oils, seeds, and nuts. Of the vegetable oils, sunflower oil is particularly rich in linoleic acid. On the other hand, camelina oil and linseed oils are rich in alpha-linolenic acid.
High intakes of linoleic acid and its concentration in plasma, for example, have been associated with a reduced risk of type 2 diabetes and cardiovascular disease, but the link to alpha-linolenic acid remains unclear. As metabolites of linoleic acid and alpha-linolenic acid, important lipid mediators are produced by the body, but some also induce inflammation.
In the new study, the researchers explored whether rs174550 mutations in FADS1 Gene modification of the effect of alpha-linolenic acid and linoleic acid on plasma fatty acid composition, and the concentrations of polyunsaturated fatty acid-derived lipid mediators. Two different pregnant women FADS1 Genotypes were recruited from among the men participating in the Metabolic Syndrome in Men Study, METSIM. They supplemented their diet with 30-50ml of camelina or sunflower oil daily for eight weeks.
“Our research design, that is, recruiting subjects on the basis of their genetic background, has proven effective in investigating the interactions between diet and genes,” says Maria Lankinen, a postdoctoral researcher from the University of Eastern Finland.
The body can make eicosapentaenoic acid from alpha-linolenic acid, and arachidonic acid from linoleic acid, for example. These long-chain fatty acids, and the lipid intermediates produced from them, are involved in many functions in the body, such as the inflammatory response and vascular function.
The study showed that FADS1 Genotype plays a major role, for example, in how efficiently essential fatty acids are converted into arachidonic acid and eicosapentaenoic acid. The FADS1 Genotype also affected the concentrations of metabolites derived from them.
Use of alpha-linolenic acid-rich camelina oil increased the concentration of eicosapentaenoic acid and lipid mediators derived from it in only one of the studied genotypes. In contrast, the use of sunflower oil rich in linoleic acid did not increase the concentration of arachidonic acid or lipid mediators derived from it in carriers of either genotype.
“The changes we observed in plasma concentrations of eicosapentaenoic acid were the same level as in our previous study, where people ate fatty fish that contained eicosapentaenoic acid. However, an interesting observation is that when using camelina oil, the changes only occurred in one of the genotypes that been studied,” says Moronen.
According to the researchers, the findings give reason to consider whether it is possible to give increasingly individualized guidance about the intake of alpha-linolenic acid and linoleic acid. However, more research is needed.
The study was conducted in collaboration with Karolinska Institutet, and the results have been published in Molecular Nutrition and Food Research.