Indices of fatty acid desaturase activity in healthy human subjects: effects of different types of dietary fat

• Published in: British journal of nutrition Vol. 110; no. 5; pp. 871 - 879
• Main Authors: Vessby, Bengt, Gustafsson, Inga-Britt, Tengblad, Siv, Berglund, Lars
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 14.09.2013
• Subjects: Adult; alpha-linolenic acid; Biological and medical sciences; blood lipids; blood serum; cholesteryl esters; Culinary Arts and Meal Science; Diet; Dietary fat; Dietary Fats - classification; Dietary Fats - pharmacology; Esters; fatty acid composition; Fatty acid desaturase index; Fatty Acid Desaturases - classification; Fatty Acid Desaturases - genetics; Fatty Acid Desaturases - metabolism; Fatty acids; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic - drug effects; Human and Clinical Nutrition; Humans; insulin resistance; Lipid Metabolism; Lipids; Lipids - blood; Male; metabolic diseases; Metabolic disorders; metabolism; Metabolites; Middle Aged; milk fat; Muscle, Skeletal - chemistry; Muscle, Skeletal - metabolism; Måltidskunskap; Nutrition; nutritional intervention; obesity; Oils & fats; omega-3 fatty acids; phospholipids; Serum lipid fatty acid composition; Skeletal muscle; stearoyl-CoA desaturase; Striated muscle. Tendons; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: osteoarticular system, musculoskeletal system; Dietary fat; Fatty acid desaturase index; Skeletal muscle; Serum lipid fatty acid composition; Human; Healthy subject; Nutrition; Lipids; Index; Striated muscle; Fatty acids; Fat; Serum; Chemical composition
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114512005934

Δ9-Desaturase (stearoyl-CoA desaturase 1, SCD-1) regulates the desaturation of SFA, mainly stearic and palmitic, to MUFA. Δ6-Desaturase (D6D) and Δ5-desaturase (D5D) are involved in the metabolism of linoleic and α-linolenic acid to polyunsaturated metabolites. The objective of the present study was to study the effects of different types of dietary fat on indices of fatty acid desaturase (FADS) activity (evaluated as product:precursor ratios) in plasma and skeletal muscle in human subjects. A high SCD-1 index has been related to obesity and metabolic disorders, while the D5D index is associated with insulin sensitivity. Fatty acid composition of serum and skeletal muscle lipids was analysed by GLC during a randomised, controlled, 3-month dietary intervention in healthy subjects. A comparison of the effects of a diet containing butter fat (SFA, n 17) with a diet containing monounsaturated fat (MUFA, n 17), keeping all other dietary components constant, showed a reduced SCD-1 activity index by 20 % on the MUFA diet compared with the SFA diet assessed in serum cholesteryl esters. The D6D and D5D indices remained unaffected. Supplementation with long-chain n-3 fatty acids reduced the SCD-1 index by a similar magnitude while the D6D index decreased and the D5D index increased. It is concluded that changes in the type of fat in the diet affect the indices of FADS activity in serum and skeletal muscle in human subjects. The desaturase activity indices estimated from the serum lipid ester composition are significantly related to corresponding indices studied in skeletal muscle phospholipids.