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

Abstract

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.

Figures

FIGURE 1

Mean (±SEM) time-dependent effect of conjugated linoleic acid (CLA) in reducing BMI in obese postmenopausal women with type 2 diabetes. (•) Subjects receiving CLA supplementation; (▴) subjects receiving safflower oil (SAF) supplementation. Subjects indicated with the dashed line received CLA from weeks 0 to 16 then crossed over to receive SAF from weeks 20 to 36. Subjects indicated with the solid line received SAF from weeks 0 to 16 then CLA from weeks 20 to 36. Dotted line indicates the washout period (weeks 16–20). Diet period 1: CLA, n = 22 in week 0, n = 17 in week 4, n = 17 in week 8, n = 17 in week 12, n = 16 in week 16; SAF, n = 33 in week 0, n = 31 in week 4, n = 28 in week 8, n = 27 in week 12, n = 27 in week 16; diet period 2: CLA, n = 27 in week 20, n = 27 in week 24, n = 24 in week 28, n = 24 in week 32, n = 22 in week 36; SAF, n = 16 in week 20, n = 14 in week 24, n = 14 in week 28, n = 13 in week 32, n = 13 in week 36.