Butter Naturally Enriched in Conjugated Linoleic Acid and Vaccenic Acid Alters Tissue Fatty Acids and Improves the Plasma Lipoprotein Profile in Cholesterol-Fed Hamsters

Abstract

Butter, which is naturally enriched in cis-9, trans-11 conjugated linoleic acid (rumenic acid; RA) and vaccenic acid (VA), has been shown to be an effective anticarcinogen in studies with animal models; however, there has been no examination of the effects of a naturally derived source of VA and RA on atherosclerosis-related biomarkers. The current study was designed to determine the effect of a diet containing VA/RA-enriched butter on plasma lipoproteins and tissue fatty acid profiles in cholesterol-fed hamsters. Male Golden Syrian hamsters were fed diets containing 0.2% cholesterol and 20% added fat as: 1) Control, 20% standard butter (CT); 2) 5% standard butter + 15% VA/RA-enriched butter (EB); 3) 15% standard butter + 5% partially-hydrogenated vegetable oil (VO). After 4 wk, plasma lipoproteins were isolated, cholesterol quantified, and tissue fatty acid profiles determined. Tissue concentrations of VA and RA were increased by consumption of the EB diet compared with both the CT and VO diets, whereas the VO diet increased their concentration compared with the CT diet only. Total and LDL cholesterol concentrations were significantly reduced in hamsters fed EB and VO compared with CT, whereas VLDL cholesterol concentrations were reduced in hamsters fed EB compared with those fed CT and VO. HDL cholesterol concentrations did not differ among treatments. The ratio of potentially atherogenic lipoproteins [VLDL + intermediate density lipoproteins (IDL) + LDL] to antiatherogenic HDL was significantly lower in hamsters fed VA/RA-enriched butter (0.60) than in those fed either control diet (1.70) or the diet containing partially hydrogenated vegetable oil (1.04). Thus, increasing the VA/RA concentration of butter results in a plasma lipoprotein cholesterol profile that is associated with a reduced risk of atherosclerosis.

Adverse effects of conjugated alpha-linolenic acids (CLnA) on lipoprotein profile on experimental atherosclerosis in hamsters

“…Moreover, RA may be more active in preventing atherosclerosis in animals (Valeille et al, 2004;Lock et al, 2005). A diet containing 18:2 trans-10, cis-12 appears to have a profound proatherogenic effect, while RA impeded the development of atherosclerosis in mice (Arbones-Mainar et al, 2006), an effect possibly explained by increased epithelial permeability with trans-10, cis-12 but not with RA (Roche et al, 2001).…”

Animal models for the atherosclerosis research: a review

“…Even with the limited data to date, the inbred F1B hamster has been more consistently reported to develop an atherogenic lipoprotein profile than any of the other three outbred strains (i.e., CR, Sasco (Kahlon et al, 1996;Kahlon et al, 1997), and Harlan hamsters (Lock et al, 2005;Tyburczy et al, 2009); for a review, see (Dillard et al, 2010)). However, due to the inconsistent and unrepeatable results of aortic lesions in response to dietary fat type in recent studies, hamsters are no longer a suitable model for studying dietinduced atherosclerosis (Dillard et al, 2010) (Table 1).…”

Estimation of cis-9, trans-11 conjugated linoleic acid content in UK foods and assessment of dietary intake in a cohort of healthy adults

“…In fact, no studies of dietary intake have reported a value that comes close to 3 g/d, meaning that for people to consume this level of CLA, supplementation will be required or ruminant foodstuffs need to be enriched artificially. CLA-enriched butter has been produced with concentrations of CLA up to 41 mg/g fat (40) , but this is not currently mass produced and is used only for scientific research purposes (41) . Even so, large quantities of this butter would need to be consumed to reach an intake of 3 g CLA, which would have obvious detrimental effects due to the high saturated fat and energy contents of butter.…”