Limited Effect of Dietary Saturated Fat on Plasma Saturated Fat in the Context of a Low Carbohydrate Diet

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 PGF2α, 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 PGF2α 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

The influence of dietary lipid composition on skeletal muscle mitochondria from mice following eight months of calorie restriction.

Calorie restriction (CR) has been shown to decrease reactive oxygen species (ROS) production and retard aging in a variety of species. It has been proposed that alterations in membrane saturation are central to these actions of CR. As a step towards testing this theory, mice were assigned to 4 dietary groups (control and 3 CR groups) and fed AIN-93G diets at 95 % (control) or 60 % (CR) of ad libitum for 8 months. To manipulate membrane composition, the primary dietary fats for the CR groups were soybean oil (also used in the control diet), fish oil or lard. Skeletal muscle mitochondrial lipid composition, proton leak, and H(2)O(2) production were measured. Phospholipid fatty acid composition in CR mice was altered in a manner that reflected the n-3 and n-6 fatty acid profiles of their respective dietary lipid sources. Dietary lipid composition did not alter proton leak kinetics between the CR groups. However, the capacity of mitochondrial complex III to produce ROS was decreased in the CR lard compared to the other CR groups. The results of this study indicate that dietary lipid composition can influence ROS production in muscle mitochondria of CR mice. It remains to be determined if lard or other dietary oils can maximize the CR-induced decreases in ROS production

Whole Blood Fatty Acid Profiles of Cold-Stunned Juvenile Green, Kemp’s Ridley, and Loggerhead Sea Turtles

When subjected to cold environmental temperatures, cheloniid sea turtles can experience debilitating lethargy, anorexia, and potential mortality in a phenomenon known as cold-stunning. Every year, hundreds to thousands of cold-stunned sea turtles are transported to rehabilitation centers for medical and nutritional care. The objective of this study was to investigate one aspect of nutritional status in cold-stunned sea turtles: fatty acid profiles. Blood was collected from eleven green (Chelonia mydas), twelve Kemp’s ridley (Lepidochelys kempii), and three loggerhead (Caretta caretta) juvenile sea turtles found cold-stunned along the coast of North Carolina, USA. Whole blood (~160 µL) was dried onto specialized paper spot cards, frozen, and subsequently analyzed via gas chromatography to quantify fatty acid percentages. Significant differences among species were identified for 19 out of 36 individual fatty acids analyzed and six out of seven fatty acid groups evaluated (P < 0.5). The whole blood fatty acid profiles of cold-stunned green and Kemp’s ridley sea turtles were similar to prior published profiles of healthy conspecifics. Marginal numerical differences noted upon visual comparison included that cold-stunned sea turtles had lower proportions of total polyunsaturated fatty acids (PUFA) and monoenes and higher proportions of total saturated fatty acids relative to healthy conspecifics. These differences may reflect acute impacts of cold-stunning on circulating plasma fatty acids or may be the result of natural seasonal variations. These data provide practical information to aid in the diet design of sea turtles in rehabilitation settings

Attitudes Toward Advanced Licensing for Macro Social Work Practice

Trends in clinical licensing and a renewed energy to strengthen macro practice are raising questions about the appropriateness of licensure for macro social work practice. This article presents findings from an online survey of macro social work educators and macro social work practitioners exploring their attitudes toward an advanced-level macro social work license. Faculty and practitioner responders agreed that there is a role for advanced-licensing of macro social work practice; however, the lack of a collectively strong response reflects a current state of ambivalence toward advanced-level licensing for macro practice. Implications from these findings on contemporary social work are discussed