Plasma lipoproteins in soy-treated postmenopausal women: a double-blind, placebo-controlled trial.
OBJECTIVE
Postmenopausal modification of the lipid profile plays a major role in the risk of ischemic heart disease. Lifestyle counseling and estrogen replacement therapy have all been proposed as first-line measures, but there is no agreement on the best way to treat climacteric dyslipidemia. Soybean-based diet seems particularly attractive in this context, given its cholesterol lowering potential, its hypothetical anticancerous effects and possible modification of climacteric symptoms.


RESULTS
We evaluated the effect of 60 g isolated soy protein (ISP) daily on the lipid profile of 104 postmenopausal women (53.3 +/- 3.3 years) in a double-blind, parallel, placebo-controlled (caseinate) trial, as part of a broader assessment of the effect of ISP on climacteric symptomatology. Serum total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apo A-I, apo B and lipoprotein (a) were determined before and after a 12-week diet modification. Seventy-seven women completed the trial. Both soy and placebo determined a significant reduction in total cholesterol (-0.42 +/- 0.79 and -0.40 +/- 0.57 mmol/L) and LDL-cholesterol (-0.35 +/- 0.72 and -0.31 +/- 0.54 mmol/L), but only soy had a significant lowering effect on apo B and the LDL-cholesterol/HDL-cholesterol ratio (-6% and -8% from baseline respectively); lipoprotein (a) plasma levels were not significantly changed by either treatment. Forty-four women were dyslipidemic at baseline; those with increased LDL concentrations showed a somewhat greater improvement in their lipoprotein profile (LDL-cholesterol and apo B reduction) with soy rather than placebo. No further information emerged when the subjects were divided into three apo E phenotypes.


CONCLUSIONS
We conclude that diet supplementation with 60 g ISP is slightly better than caseinate in favorably modifying the lipoprotein metabolism of postmenopausal women; this effect is more evident in hypercholesterolemic subjects.
Vigna
G B
GB
Department of Clinical and Experimental Medicine, Section of Internal Medicine II, University of Ferrara, Via Savonarola 9, 44100 Ferrara, Italy. vgg@unite.it
Pansini
F
F
Bonaccorsi
G
G
Albertazzi
P
P
Donegà
P
P
Zanotti
L
L
De Aloysio
D
D
Mollica
G
G
Fellin
R
R
D002364:Caseins / Q000627:therapeutic use; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D019584:Hot Flashes / Q000178:diet therapy; D006801:Humans; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000209:etiology / Q000517:prevention & control; D017698:Postmenopause / Q000097:blood*; D030262:Soybean Proteins / Q000627:therapeutic use*; D014280:Triglycerides / Q000097:blood
D002364:Caseins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008055:Lipids; D008074:Lipoproteins; D030262:Soybean Proteins; D014280:Triglycerides