American Journal of Clinical Nutrition Lipids

Comparison of dietary conjugated linoleic acid with safflower oil on body composition in obese postmenopausal women with type 2 diabetes mellitus [Lipids]

Thu, 20 Aug 2009 10:03:26 PDT

Background: Weight loss may improve glucose control in persons with type 2 diabetes. The effects of fat quality, as opposed to quantity, on weight loss are not well understood.

Objective: We compared the effects of 2 dietary oils, conjugated linoleic acid (CLA) and safflower oil (SAF), on body weight and composition in obese postmenopausal women with type 2 diabetes.

Design: This was a 36-wk randomized, double-masked, crossover study. Fifty-five obese postmenopausal women with type 2 diabetes received SAF or CLA (8 g oil/d) during two 16-wk diet periods separated by a 4-wk washout period. Subjects met monthly with the study coordinator to receive new supplements and for assessment of energy balance, biochemical endpoints, or anthropometric variables.

Results: Thirty-five women completed the 36-wk intervention. Supplementation with CLA reduced body mass index (BMI) (P = 0.0022) and total adipose mass (P = 0.0187) without altering lean mass. The effect of CLA in lowering BMI was detected during the last 8 wk of each 16-wk diet period. In contrast, SAF had no effect on BMI or total adipose mass but reduced trunk adipose mass (P = 0.0422) and increased lean mass (P = 0.0432). SAF also significantly lowered fasting glucose (P = 0.0343) and increased adiponectin (P = 0.0051). No differences were observed in dietary energy intake, total fat intake, and fat quality in either diet period for either intervention.

Conclusions: Supplementation with CLA and SAF exerted different effects on BMI, total and trunk adipose mass, and lean tissue mass in obese postmenopausal women with type 2 diabetes. Supplementation with these dietary oils may be beneficial for weight loss, glycemic control, or both.

Association of cholesterol oxidation and abnormalities in fatty acid metabolism in cystic fibrosis [Lipids]

Thu, 20 Aug 2009 10:03:26 PDT

Background: Disarrangement in fatty acids and oxidative stress are features of cystic fibrosis. Cholesterol is very sensitive to oxidative stress.

Objectives: The objectives were to examine whether cholesterol oxidation products are altered in cystic fibrosis and whether they are associated with fatty acids and with characteristics of the disease state.

Design: 7-Ketocholesterol and 7β-hydroxycholesterol (prototype molecules of free radical–mediated cholesterol oxidation) and the fatty acid profile were assessed by mass spectrometry in patients and in sex- and age-matched control subjects.

Results: In a comparison with control subjects, mean (±SD) cholesterol oxidation was higher (7-ketocholesterol: 11.31 ± 5.1 compared with 8.33 ± 5.5 ng/mL, P = 0.03; 7β-hydroxycholesterol: 14.5 ± 6.8 compared with 9.7 ± 4.1 ng/mL, P = 0.004), total saturated fatty acids were higher (31.90 ± 1.93% compared with 30.31 ± 0.98%, P < 0.001), monounsaturated fatty acids were higher (29.14 ± 3.85% compared with 25.88 ± 2.94%, P = 0.004), -6 (n–6) polyunsaturated fatty acids were lower (34.84 ± 4.77 compared with 39.68 ± 2.98%, P < 0.0001), and -3 (n–3) polyunsaturated fatty acids were comparable in patients with cystic fibrosis. Oxysterols were inversely associated with 24:0 and 18:2 -6 fatty acids but did not correlate with the increased oleic acid or with any of the -3 fatty acids.

Conclusions: Cystic fibrosis is characterized by relevant cholesterol oxidation that is associated with an abnormal fatty acid profile. The interplay between oxysterols and fatty acids potentially provides insight into the biological mechanisms that underlie this complex disease.

Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjects [Lipids]

Qin, Y., Xia, M., Ma, J., Hao, Y., Liu, J., Mou, H., Cao, L., Ling, W. — Thu, 20 Aug 2009 10:03:26 PDT

Background: Anthocyanins have been shown to exert benefits on the lipid profile in many animal models. Whether these molecules have similar beneficial effects in humans is currently unknown.

Objective: The objective was to investigate the effects of berry-derived anthocyanin supplements on the serum lipid profile in dyslipidemic patients.

Design: A total of 120 dyslipidemic subjects (age 40–65 y) were given 160 mg anthocyanins twice daily or placebo for 12 wk in a double-blind, randomized, placebo-controlled trial.

Results: Anthocyanin consumption increased HDL-cholesterol concentrations (13.7% and 2.8% in the anthocyanin and placebo groups, respectively; P < 0.001) and decreased LDL-cholesterol concentrations (13.6% and –0.6% in the anthocyanin and placebo groups, respectively; P < 0.001). Cellular cholesterol efflux to serum increased more in the anthocyanin group than in the placebo group (20.0% and 0.2%, respectively; P < 0.001). Anthocyanin supplementation decreased the mass and activity of plasma cholesteryl ester transfer protein (CETP) (10.4% and 6.3%, respectively, in the anthocyanin group and –3.5% and 1.1%, respectively, in the placebo group; P < 0.001). In the anthocyanin group, the change in HDL cholesterol was negatively correlated with the change in CETP activity (r_s = –0.330). The change in LDL cholesterol was positively correlated with the change in CETP mass (r_s = 0.354). The change in cellular cholesterol efflux to serum was positively correlated with the change in HDL cholesterol (r_s = 0.485). In vitro, cyanidin 3-O-β-glucosides dose-dependently lowered CETP activity in human HepG2 cells.

Conclusions: Anthocyanin supplementation in humans improves LDL- and HDL-cholesterol concentrations and enhances cellular cholesterol efflux to serum. These benefits may be due to the inhibition of CETP.