Soy inclusion in the diet improves features of the metabolic syndrome: a randomized crossover study in postmenopausal women.
BACKGROUND
Little evidence exists regarding the effects of soy consumption on the metabolic syndrome in humans.


OBJECTIVE
We aimed to determine the effects of soy consumption on components of the metabolic syndrome, plasma lipids, lipoproteins, insulin resistance, and glycemic control in postmenopausal women with the metabolic syndrome.


METHODS
This randomized crossover clinical trial was undertaken in 42 postmenopausal women with the metabolic syndrome. Participants were randomly assigned to consume a control diet (Dietary Approaches to Stop Hypertension, DASH), a soy-protein diet, or a soy-nut diet, each for 8 wk. Red meat in the DASH period was replaced by soy-protein in the soy-protein period and by soy-nut in the soy-nut period.


RESULTS
The soy-nut regimen decreased the homeostasis model of assessment-insulin resistance score significantly compared with the soy-protein (difference in percentage change: -7.4 +/- 0.8; P < 0.01) or control (-12.9 +/- 0.9; P < 0.01) diets. Consumption of soy-nut also reduced fasting plasma glucose more significantly than did the soy-protein (-5.3 +/- 0.5%; P < 0.01) or control (-5.1 +/- 0.6%; P < 0.01) diet. The soy-nut regimen decreased LDL cholesterol more than did the soy-protein period (-5.0 +/- 0.6%; P < 0.01) and the control (-9.5 +/- 0.6%; P < 0.01) diet. Soy-nut consumption significantly reduced serum C-peptide concentrations compared with control diet (-8.0 +/- 2.1; P < 0.01), but consumption of soy-protein did not.


CONCLUSIONS
Short-term soy-nut consumption improved glycemic control and lipid profiles in postmenopausal women with the metabolic syndrome.
Azadbakht
Leila
L
Department of Human Nutrition, School of Nutrition and Food Science, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. lazadbakht@hotmail.com
Kimiagar
Masoud
M
Mehrabi
Yadollah
Y
Esmaillzadeh
Ahmad
A
Padyab
Mojgan
M
Hu
Frank B
FB
Willett
Walter C
WC
D000273:Adipose Tissue / Q000033:anatomy & histology; D015992:Body Mass Index; D049628:Body Size; D002641:Chicago; D018592:Cross-Over Studies; D004032:Diet; D004038:Diet, Reducing; D005260:Female; D038321:Glycemic Index / Q000502:physiology*; D006801:Humans; D007657:Ketone Bodies / Q000652:urine; D024821:Metabolic Syndrome / Q000517:prevention & control*; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy*; D017698:Postmenopause; D011788:Quality of Life; D030262:Soybean Proteins; D015431:Weight Loss
D007657:Ketone Bodies; D030262:Soybean Proteins