Increasing the Amount of Fat in a Conjugated Linoleic Acid–Supplemented Diet Reduces Lipodystrophy in Mice

Abstract

Conjugated linoleic acid (CLA) is a naturally occurring group of dienoic derivatives of linoleic acid found in beef and dairy products. However, when 1 g CLA/100 g diet was given to mice in a low fat diet (4 g fat/100 g diet), they showed a marked decrease in fat mass, but demonstrated symptoms of lipoatrophic diabetes, i.e., marked hepatomegaly and insulin resistance. In this study, to determine whether the decrease in adipose tissue was responsible for these adverse effects, mice were fed different doses of CLA and dietary fat. In Experiment 1, mice were fed different doses of CLA (0, 0.1 and 1 g CLA/100 g diet) in a fixed 4 g fat/100 g diet; in those fed 0.1 g CLA, subcutaneous white adipose tissue (WAT) weight was 48% lower than in mice fed 0 g CLA. The mice fed 0.1 g CLA did not exhibit hepatomegaly and insulin resistance. In Experiment 2, mice were fed for 5 mo different amounts of dietary fat (4, 13 and 34 g fat/100 g diet) in 0 or 1 g CLA/100 g diet; in mice fed 1 g CLA with 34 g fat, retroperitoneal and subcutaneous WAT weights were 76 and 79% lower, respectively, than those of mice fed 0 g CLA with 34 g fat. Mice fed 1 g CLA in the diet with 34 g fat had normal plasma insulin concentrations and a 45% greater liver weight. These data suggested that the percentage of CLA in dietary fat might be a determinant of CLA-mediated lipodystrophy.

Efficacy and safety of dietary supplements containing CLA for the treatment of obesity

“…Similarly, despite resulting in decreased body weight, t10,c12 supplementation in mice was associated with increased serum glucose and insulin levels, whereas the c9,t11 supplementation group showed no weight loss, but lowered triglycerides and FFA (29). This study is in line with other studies in mice showing that CLA supplementation (36% t10,c12 isomer) results in marked reductions in body fat, although this was associated with the development of insulin resistance, resulting in a metabolic state resembling lipoatrophic diabetes (30,31). Similar observations have been reported by other researchers, showing that mice fed purified t10,c12 CLA or CLA mixtures develop hyperinsulinemia and fatty liver (29,(32)(33)(34).…”

Impact of dietary betaine and conjugated linoleic acid on insulin sensitivity, protein and fat metabolism of obese pigs

“…The impact of dietary CLA on hepatic steatosis and insulin sensitivity is controversial because of differences in species, isomer responses and degree and sensitivity to changes in adiposity (Tsuboyama-Kasaoka et al, 2003;Nagao et al, 2005;Wang et al, 2006). In this study, we investigated the effects of dietary CLA and betaine in a highly adipogenic pig model.…”

Safety of Dietary Conjugated Linoleic Acid (CLA) in a 12-weeks Trial in Healthy Overweight Japanese Male Volunteers

“…A toxicological study of dietary CLA in rats showed no histomorphological or hematological changes [21][22][23] . In contrast, dietary CLA leads to lipid accumulation and enlargement of the liver in mice, as a result of increased fatty acid mobilization from the adipose tissue [24][25][26] . This has not been confirmed in other animal species 5,27) .…”