Milk-Derived Fatty Acids Are Associated with a More Favorable LDL Particle Size Distribution in Healthy Men

Abstract

A predominance of small dense LDL (sdLDL) particles is a well-established component of the atherogenic lipoprotein phenotype associated with insulin resistance and increased risk for coronary heart disease. However, the influence of diet on LDL particle size distribution is not clear. We investigated (cross-sectionally) the relations between LDL profile and dietary fatty acids (FAs) in 291 healthy men (62-64 y old) with a range of insulin sensitivities. Individuals completed a 7-d dietary record, and fasting plasma insulin, lipid, and lipoprotein concentrations as well as serum and adipose tissue FA composition were determined. The LDL profile was examined by polyacrylamide gradient gel electrophoresis, protein-staining, and quantitative scanning, giving LDL peak particle size and the percentage distribution of LDL in 4 subfractions. The men were divided into tertiles of percentage distribution of sdLDL. Small dense LDL was positively related to plasma triacylglycerol and fasting insulin concentrations (both P < 0.0001) and inversely related to HDL cholesterol (P < 0.0001). No strong relations were found between sdLDL and the reported intake of SFA, monounsaturated fatty acids, or PUFA. However, individual FAs typically found in milk products were associated with a more favorable LDL profile (i.e., fewer sdLDL particles). This was shown for 4:0-10:0 and 14:0 in the diet (both P < 0.05), 15:0 and 17:0 in serum phospholipids (both P < 0.05), and 15:0 in serum nonesterified FAs (P < 0.01). Furthermore, 20:3(n-6) in adipose tissue and serum phospholipids was positively related to sdLDL. Therefore, LDL particle size distribution appears to be modified by dietary factors with an apparently beneficial effect of milk products.

Dairy consumption and patterns of mortality of Australian adults

“…As dairy products, and in particular the full-fat varieties, contribute to the intake of saturated fatty acids, dairy products have generally been suggested to increase CVD risk, although some studies found no association (Tholstrup, 2006) and others found an inverse association between dairy intake and the risk of CVD (Ness et al, 2001) or its risk factors (Samuelson et al, 2001;Pereira et al, 2002;Sjogren et al, 2004). We found no strong evidence that any of the individual full-fat dairy foods was underlying the inverse association between full-fat dairy intake and CVD mortality.…”

Fatty acid desaturases in human adipose tissue: relationships between gene expression, desaturation indexes and insulin resistance

“…The men were selected to represent a wide range of fasting plasma insulin concentrations. Recruitment details, exclusion criteria, clinical procedures and dietary assessment (7 day dietary records) have been described previously [11]. Subcutaneous adipose tissue biopsies were taken from the left upper buttock for subsequent analysis; smaller biopsies were taken from all individuals for fatty acid composition analysis and larger biopsies were taken from a subset of 87 individuals (equally distributed throughout the tertiles of fasting insulin concentrations).…”

“…Laboratory procedures Methods for determination of plasma glucose, insulin, proinsulin, uric acid, triacylglycerol, LDL peak particle size distribution and cholesterol in VLDL, LDL and HDL have been described previously [11]. Circulating levels of oxidised LDL, C-reactive protein (CRP), TNFα and IL-6 were derived as described previously [12].…”

The protective effect of processed cheese against hyperlipidemia in rats

“…For this reason, consumption of high fat dairy products would be expected to be associated with CVD risk. However, results of epidemiologic surveys, animal experiments, and human dietary studies have been conflicting [27,28,36,38]. This discrepancy may be ascribed to the differences in the atherogenic effects of various dairy products.…”