Soy protein containing isoflavones reduces the size of atherosclerotic plaques without affecting coronary artery reactivity in adult male monkeys.
The cardiovascular effects of dietary soy on men or adult male experimental animals have received little attention. We determined the effects of long-term (31 mo) consumption of a commercially available soy protein concentrate containing experimentally varied concentrations of isoflavones on the development of atherosclerosis and vascular reactivity in adult male monkeys. The monkeys were fed atherogenic diets that differed only in the source of protein: Control (n = 30), casein and lactalbumin; low-isoflavone soy (n = 30), a mixture of unmodified soy protein isolate and isoflavone-depleted soy protein isolate containing 0.94 mg of isoflavones/g protein; and high-isoflavone soy (n = 31), unmodified soy protein isolate containing 1.88 mg of isoflavone/g protein. Plasma LDL cholesterol was reduced, whereas HDL cholesterol and apolipoprotein A-1 (P < 0.05) were increased in both groups that consumed soy protein. Atherosclerosis (mean plaque size in the coronary arteries) was reduced by approximately 34% (P < 0.05) in both groups fed soy protein. There were no effects of dietary soy on endothelium-dependent or -independent reactivity of coronary arteries. The results indicate that long-term consumption of soy protein containing a modest amount of isoflavones inhibits the early progression of coronary artery atherosclerosis without affecting endothelium-dependent or -independent arterial function.
Adams
Michael R
MR
Department of Pathology/Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA. madams@wfubmc.edu
Golden
Deborah L
DL
Williams
J Koudy
JK
Franke
Adrian A
AA
Register
Thomas C
TC
Kaplan
Jay R
JR
D000821:Animal Feed; D000818:Animals; D050197:Atherosclerosis / Q000517:prevention & control*; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology*; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology*; D004036:Diet, Atherogenic; D018753:Diet, Protein-Restricted; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D007529:Isoflavones / Q000008:administration & dosage / Q000627:therapeutic use*; D008252:Macaca fascicularis; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology; D030262:Soybean Proteins; D014665:Vasodilator Agents / Q000494:pharmacology
D007529:Isoflavones; D030262:Soybean Proteins; D014665:Vasodilator Agents; D005996:Nitroglycerin