Fatty acid composition of skeletal muscle reflects dietary fat composition in humans.
BACKGROUND
It is still unknown whether the fatty acid composition of human skeletal muscle lipids is directly influenced by the fat composition of the diet.


OBJECTIVE
We investigated whether the fatty acid composition of the diet is reflected in the fatty acid profile of skeletal muscle phospholipids and triacylglycerols.


METHODS
Thirty-two healthy adults (25 men and 7 women) included in a larger controlled, multicenter dietary study were randomly assigned to diets containing a high proportion of either saturated fatty acids (SFAs) [total fat, 36% of energy; SFAs, 18% of energy; monounsaturated fatty acids (MUFAs), 10% of energy] or MUFAs (total fat, 35% of energy; SFAs, 9% of energy; MUFAs, 19% of energy) for 3 mo. Within each diet group, there was a second random assignment to supplementation with fish oil capsules [containing 3.6 g n-3 fatty acids/d; 2.4 g eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)] or placebo. A muscle biopsy sample was taken from the vastus lateralis muscle after the diet period. Parallel analyses of diet and supplementation effects were performed.


RESULTS
The proportions of myristic (14:0), pentadecanoic (15:0), heptadecanoic (17:0), and palmitoleic (16:1n-7) acids in the skeletal muscle phospholipids were higher and the proportion of oleic acid (18:1n-9) was lower in the SFA group than in the MUFA group. The proportion of total n-3 fatty acids in the muscle phospholipids was approximately 2.5 times higher, with a 5 times higher proportion of eicosapentaenoic acid (20:5n-3), in subjects supplemented with n-3 fatty acids than in those given placebo. Similar differences were observed in the skeletal muscle triacylglycerols.


CONCLUSIONS
The fatty acid composition of skeletal muscle lipids reflects the fatty acid composition of the diet in healthy men and women.
Andersson
Agneta
A
Unit for Clinical Nutrition Research, Department of Public Health and Caring Sciences/Geriatrics, Uppsala University, Uppsala, Sweden. agneta.andersson@pubcare.uu.se
Nälsén
Cecilia
C
Tengblad
Siv
S
Vessby
Bengt
B
D000328:Adult; D000368:Aged; D001706:Biopsy; D002788:Cholesterol Esters / Q000097:blood; D004041:Dietary Fats / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage; D002149:Energy Intake; D005227:Fatty Acids / Q000008:administration & dosage* / Q000032:analysis* / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000737:chemistry*; D010743:Phospholipids / Q000032:analysis / Q000097:blood; D010919:Placebos; D014280:Triglycerides / Q000032:analysis
D002788:Cholesterol Esters; D004041:Dietary Fats; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D010743:Phospholipids; D010919:Placebos; D014280:Triglycerides; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid