Effects of dairy products naturally enriched with cis-9,trans-11 conjugated linoleic acid on the blood lipid profile in healthy middle-aged men.
BACKGROUND
Interest in the development of dairy products naturally enriched in conjugated linoleic acid (CLA) exists. However, feeding regimens that enhance the CLA content of milk also increase concentrations of trans-18:1 fatty acids. The implications for human health are not yet known.


OBJECTIVE
This study investigated the effects of consuming dairy products naturally enriched in cis-9,trans-11 CLA (and trans-11 18:1) on the blood lipid profile, the atherogenicity of LDL, and markers of inflammation and insulin resistance in healthy middle-aged men.


METHODS
Healthy middle-aged men (n = 32) consumed ultra-heat-treated milk, butter, and cheese that provided 0.151 g/d (control) or 1.421 g/d (modified) cis-9,trans-11 CLA for 6 wk. This was followed by a 7-wk washout and a crossover to the other treatment.


RESULTS
Consumption of dairy products enriched with cis-9,trans-11 CLA and trans-11 18:1 did not significantly affect body weight, inflammatory markers, insulin, glucose, triacylglycerols, or total, LDL, and HDL cholesterol but resulted in a small increase in the ratio of LDL to HDL cholesterol. The modified dairy products changed LDL fatty acid composition but had no significant effect on LDL particle size or the susceptibility of LDL to oxidation. Overall, increased consumption of full-fat dairy products and naturally derived trans fatty acids did not cause significant changes in cardiovascular disease risk variables, as may be expected on the basis of current health recommendations.


CONCLUSIONS
Dairy products naturally enriched with cis-9,trans-11 CLA and trans-11 18:1 do not appear to have a significant effect on the blood lipid profile.
Tricon
Sabine
S
Hugh Sinclair Unit of Human Nutrition, School of Food Biosciences and the School of Animal and Microbial Sciences, The University of Reading, Whiteknights, Reading RG6 6AP, United Kingdom. p.yaqoob@reading.ac.uk
Burdge
Graham C
GC
Jones
Emma L
EL
Russell
Jennifer J
JJ
El-Khazen
Soraya
S
Moretti
Emmanuelle
E
Hall
Wendy L
WL
Gerry
Andrew B
AB
Leake
David S
DS
Grimble
Robert F
RF
Williams
Christine M
CM
Calder
Philip C
PC
Yaqoob
Parveen
P
D000328:Adult; D002318:Cardiovascular Diseases / Q000097:blood / Q000517:prevention & control; D008076:Cholesterol, HDL / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D008078:Cholesterol, LDL / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D018592:Cross-Over Studies; D003611:Dairy Products / Q000032:analysis; D004311:Double-Blind Method; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D007536:Isomerism; D044243:Linoleic Acids, Conjugated / Q000737:chemistry / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D012307:Risk Factors
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D044243:Linoleic Acids, Conjugated