Conjugated linoleic acid decreases fat accretion in pigs: evaluation by dual-energy X-ray absorptiometry

Abstract

Thirty female Large White £ Landrace pigs (average weight 57·2 (SD 1·9) kg) were allocated to one of six dietary treatments containing 0, 1·25, 2·5, 5·0, 7·5 or 10·0 g 55 % conjugated linoleic acids (CLA) isomers (CLA-55)/kg diet and fed for 8 weeks. Each pig was scanned at 0, 28 and 56 d and again at post slaughter using dual-energy X-ray absorptiometry (DXA) to determine the temporal pattern of body composition responses. Values determined by DXA were adjusted using regression equations generated from validation experiments between chemically and DXA-predicted values. Overall, there was a significant linear reduction in fat content with the increasing levels of CLA in the diet (P¼0·007, P¼0·011, P¼ 0·008 at week 4, week 8 and for the carcass, respectively). The greatest improvement was recorded at the early stages of CLA supplementation and for the highest dose of CLA (week 4, 219·2 % compared with week 8, 2 13·7 %). In the first 4 weeks of feeding CLA, pigs receiving 10 g CLA-55/kg diet deposited 93 g less fat/d than pigs fed basal diets (P¼0·002) compared with only 6 g less fat than control animals in the final 4 weeks. Lean content and lean deposition rate were maximised at 5 and 2·5 g CLA-55/kg diet for the first 4 weeks (P¼ 0·016) and the final 4 weeks of treatment ðP ¼ 0·17Þ; respectively. DXA estimates of bone mineral content and bone mineral density were not affected by CLA supplementation throughout the experiment. These data demonstrate that dietary CLA decreases body fat in a dose-dependent manner and that the response is greatest over the initial 4 weeks of treatment.Conjugated linoleic acid: Dual-energy X-ray absorptiometry: Body composition: Pig Conjugated linoleic acid (CLA) represents a mixture of positional and geometric isomers (18 : 2n-6) of linoleic acid with conjugated double bonds located at positions 7,9-, 8,10-, 9,11-, 10,12-or 11,13-on the C chain. CLA exerts many positive health effects in experimental models including anticarcinogenic and anti-tumorogenic as well as anti-atherogenic and antidiabetogenic properties (for reviews, see Whigham et al. 2000;Pariza et al. 2001). Another biological effect of CLA relates to fat accretion and nutrient partitioning. Dietary CLA supplementation reduces body fat mass in rodents (Chin et al. 1994;Park et al. 1995;DeLany et al. 1999) and pigs (Ostrowska et al. 1999). These findings were based on experiments involving slaughter and subsequent chemical analysis in which the ultimate rates of change in body composition were determined at the conclusion of CLA supplementation. However, little is known about the longitudinal effects of CLA supplementation on body composition and generation of such data requires killing large numbers of animals at various stages of development. Alternatively, body composition can be measured in live animals and carcasses using dual-energy X-ray absorptiometry (DXA) (Mitchell et al. 1998;Lukaski et al. 1999;Suster et al. 2000), which is non-invasive and allows longitudinal studies in the same animal. The DXA apparatus can...

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

“…Because leptin is secreted mainly by adipocytes, circulating levels correlate directly with body mass index in humans (Ahima and Flier, 2000), with a positive correlation between circulating leptin levels and adiposity also reported in pigs (Barb et al, 2001). As CLA is reported to reduce body fat content (Ostrowska et al, 2003), a reduction in plasma leptin levels would be expected in CLA-supplemented animals (Kang and Pariza, 2002) unless there is central or peripheral leptin resistance. Leptin, by binding to its receptors located in skeletal muscle and fat cells promotes energy dissipation and prevents fatty acid accumulation in these tissues (Ceddia, 2005).…”

Conjugated linoleic acid and obesity control: efficacy and mechanisms

“…11,13,15,[21][22][23]37 It has not been established whether CLA continues to offer antiadiposity action over the long-term period in animals or humans. Although no adverse effects of CLA have been observed in pigs, [32][33][34][35][36]39,[41][42][43] fat liver and spleen as well as insulin resistance have been reported in mice after LCA supplementation. 11,12,15,20,38,98,99 Results of these studies have raised a question relevant to humans of whether it is safe to supplement with CLA.…”

“…16,32,[34][35][36]39,[41][42][43] It has been reported that back-fat thickness was significantly decreased in male and female pigs supplemented with 2.0% CLA mixture containing 15% c9t11 and 15% t10c12 isomers during the growing-finishing period (24-117 kg). 35 Similarly, Wiegnand et al 36 observed a decrease in fat deposition in growing-finishing (28-115 kg) pigs fed 0.75% CLA mixture containing 27% c9t11 and 20% t10c12 isomers.…”

“…A linear pattern of reduction in the fat deposition was observed in finishing pigs when supplemented with 0.07 to 0.55% CLA containing 25% c9t11 and 31% t10c12 isomers. 16,39 O'Quinn et al 34 reported that fat Conjugated linoleic acid and obesity YW Wang and PJH Jones deposition was unchanged in pigs given 0.5% CLA mixture (the composition of CLA was not provided) during the growing-finishing (38-73 kg) period. Another study also failed to show a significant effect of CLA mixture containing 21% c9t11 and 15% t10c12 isomers on fat deposition.…”

“…16,32,35,36,39 It has been reported that diet supplementation with CLA at a level as low as 0.5% reduced fat deposition in both male and female ICR mice. 10 Marked reductions in white and brown fat deposition have been observed in female and male C57BL/6J mice after feeding 1.0-1.5% CLA.…”