Conversion of alpha-linolenic acid in humans is influenced by the absolute amounts of alpha-linolenic acid and linoleic acid in the diet and not by their ratio.

摘要: BACKGROUND: Human in vivo data on dietary determinants of alpha-linolenic acid (ALA; 18:3n-3) metabolism are scarce. OBJECTIVE: We examined whether intakes ALA or linoleic (LA; 18:2n-6) their ratio influences metabolism. DESIGN: During 4 wk, 29 subjects received a control diet (7% energy from LA, 0.4% ALA, ALA-to-LA = 1:19). For the next 6 diet, low-LA (3% 1:7), high-ALA 1.1% 1:7) was consumed. Ten days before end each period, [U-13C]ALA administered orally for 9 d. oxidation determined breath. Conversion estimated by using compartmental modeling [13C]- and [12C]n-3 fatty concentrations fasting plasma phospholipids. RESULTS: Compared with group, incorporation into phospholipids increased 3.6% group (P 0.012) decreased 8.0% < 0.001). In absolute amounts, it 34.3 mg 0.020) but hardly changed group. Nearly all phospholipid pool converted eicosapentaenoic acid. docosapentaenoic docosahexaenoic 3 groups <0.1% ALA. unchanged 0.7 to 1.9 0.001) interventions. CONCLUSION: The amounts LA not ratio, determine conversion.