Effects of fish oil on metabolic responses to oral fructose and glucose loads in healthy humans.
This study examines the effect of the substitution of 6 g/day of fish oil in a saturated diet on glucose and fructose metabolism in healthy humans. Five subjects were submitted to two 3-wk controlled-diet periods (polyunsaturated/saturated = 0.21). During one period, 6 g/day of fat used for dressing were replaced by 6 g/day of fish oil [1.1 g/day of 20:5 (n-3) fatty acids and 0.7 g/day of 22:6 (n-3) fatty acids]. At the end of each period the subjects ingested a 1 g/kg fructose or glucose load 2 days apart. Plasma glucose fluxes were traced with the use of deuterated glucose and [U-13C]glucose. Substrate oxidation was measured by indirect calorimetry. Fish oil induced a 4% increase in basal and postload glycemia and a 40% decrease in insulinemia, whereas plasma C-peptide remained unaffected. Glucose fluxes were unaffected by fish oil, but carbohydrate (CHO) oxidation was reduced (fructose: 55.5 +/- 4.1 vs. 62.9 +/- 3.6 g/6 h; glucose: 36.7 +/- 4.7 vs. 50.5 +/- 4.7 g/6 h; all P < 0.05). Lipid oxidation was increased 35% by fish oil after both CHO loads. Nonoxidative glucose disposal was increased by fish oil (fructose: 9.4 +/- 2.5 vs. 2.9 +/- 1.1 g/6 h; glucose: 28.3 +/- 5.1 vs. 14.4 +/- 4.7 g/6 h; all P < 0.05). Fish oil could affect glucose transport and decrease CHO oxidation through the decrease in insulinemia and/or a specific effect on glycolytic pathway.
Delarue
J
J
Laboratoire de Nutrition et Jeune Equipe 313 Lipides et Croissance, Université de Tours, France.
Couet
C
C
Cohen
R
R
Bréchot
J F
JF
Antoine
J M
JM
Lamisse
F
F
D000284:Administration, Oral; D000328:Adult; D001792:Blood Platelets / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D004734:Energy Metabolism; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D005632:Fructose / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010084:Oxidation-Reduction; D010743:Phospholipids / Q000097:blood; D012016:Reference Values
D002096:C-Peptide; D005395:Fish Oils; D007328:Insulin; D010743:Phospholipids; D005632:Fructose; D005947:Glucose