Forsythe Cassandra E, Phinney Stephen D, Feinman Richard D, Volk Brittanie M, Freidenreich Daniel, Quann Erin, Ballard Kevin, Puglisi Michael J, Maresh Carl M, Kraemer William J, Bibus Douglas M, Fernandez Maria Luz, Volek Jeff S
Department of Kinesiology, University of Connecticut, Unit 1110, Storrs, CT 06269-1110, USA.
Lipids. 2010 Oct;45(10):947-62. doi: 10.1007/s11745-010-3467-3. Epub 2010 Sep 7.
We recently showed that a hypocaloric carbohydrate restricted diet (CRD) had two striking effects: (1) a reduction in plasma saturated fatty acids (SFA) despite higher intake than a low fat diet, and (2) a decrease in inflammation despite a significant increase in arachidonic acid (ARA). Here we extend these findings in 8 weight stable men who were fed two 6-week CRD (12%en carbohydrate) varying in quality of fat. One CRD emphasized SFA (CRD-SFA, 86 g/d SFA) and the other, unsaturated fat (CRD-UFA, 47 g SFA/d). All foods were provided to subjects. Both CRD decreased serum triacylglycerol (TAG) and insulin, and increased LDL-C particle size. The CRD-UFA significantly decreased plasma TAG SFA (27.48 ± 2.89 mol%) compared to baseline (31.06 ± 4.26 mol%). Plasma TAG SFA, however, remained unchanged in the CRD-SFA (33.14 ± 3.49 mol%) despite a doubling in SFA intake. Both CRD significantly reduced plasma palmitoleic acid (16:1n-7) indicating decreased de novo lipogenesis. CRD-SFA significantly increased plasma phospholipid ARA content, while CRD-UFA significantly increased EPA and DHA. Urine 8-iso PGF(2α), a free radical-catalyzed product of ARA, was significantly lower than baseline following CRD-UFA (-32%). There was a significant inverse correlation between changes in urine 8-iso PGF(2α) and PL ARA on both CRD (r = -0.82 CRD-SFA; r = -0.62 CRD-UFA). These findings are consistent with the concept that dietary saturated fat is efficiently metabolized in the presence of low carbohydrate, and that a CRD results in better preservation of plasma ARA.
我们最近发现，低热量碳水化合物限制饮食（CRD）有两个显著效果：（1）尽管摄入量高于低脂饮食，但血浆饱和脂肪酸（SFA）减少；（2）尽管花生四烯酸（ARA）显著增加，但炎症减少。在此，我们将这些发现扩展至8名体重稳定的男性，他们接受了两种为期6周的CRD（碳水化合物占12%能量），脂肪质量不同。一种CRD强调饱和脂肪酸（CRD-SFA，每天86克饱和脂肪酸），另一种强调不饱和脂肪（CRD-UFA，每天47克饱和脂肪酸）。所有食物都提供给受试者。两种CRD均降低了血清三酰甘油（TAG）和胰岛素，并增加了低密度脂蛋白胆固醇（LDL-C）颗粒大小。与基线相比（31.06±4.26摩尔%），CRD-UFA显著降低了血浆TAG SFA（27.48±2.89摩尔%）。然而，尽管饱和脂肪酸摄入量增加了一倍，但CRD-SFA中的血浆TAG SFA保持不变（33.14±3.49摩尔%）。两种CRD均显著降低了血浆棕榈油酸（16:1n-7），表明从头脂肪生成减少。CRD-SFA显著增加了血浆磷脂ARA含量，而CRD-UFA显著增加了二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）。CRD-UFA后，尿液8-异前列腺素F2α（8-iso PGF(2α)），一种ARA的自由基催化产物，显著低于基线（-32%）。两种CRD上，尿液8-异前列腺素F2α（8-iso PGF(2α)）的变化与磷脂ARA之间存在显著负相关（CRD-SFA中r = -0.82；CRD-UFA中r = -0.62）。这些发现与以下概念一致，即膳食饱和脂肪在低碳水化合物存在下能有效代谢，且CRD能更好地保存血浆ARA。
