Effect of Soy Nuts on Adhesion Molecules and Markers of Inflammation in Hypertensive and Normotensive Postmenopausal Women

Abstract

Recently, it was shown that substituting soy nuts for nonsoy protein in a therapeutic lifestyle change (TLC) diet lowered systolic and diastolic blood pressure by 9.9% and 6.8%, respectively, in postmenopausal women with hypertension and by 5.2% and 2.9%, respectively, in normotensive postmenopausal women. In this study, to examine mechanisms for these reductions, markers of inflammation were measured, including soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, C-reactive protein, interleukin-6, and matrix metalloproteinase-9. Sixty healthy postmenopausal women (48 normotensive and 12 with hypertension) were randomized in a crossover design to a TLC diet alone or a TLC diet in which 0.5 cups of soy nuts (25 g soy protein and 101 mg aglycone isoflavones) replaced 25 g of nonsoy protein daily. Each diet was followed for 8 weeks. Compared with the TLC diet alone, levels of soluble vascular cell adhesion molecule-1 were significantly lower on the soy diet in women with hypertension (623.6 +/- 153.8 vs 553.8 +/- 114.4 ng/ml, respectively, p = 0.003), whereas no significant differences were observed in normotensive women. Soy nuts were associated with a trend toward reduction in C-reactive protein in normotensive women. No effect on levels of soluble intercellular adhesion molecule-1, interleukin-6, or matrix metalloproteinase-9 was observed. In conclusion, the reduction in soluble vascular cell adhesion molecule-1 with soy nuts in women with hypertension suggests an improvement in endothelial function that may reflect an overall improvement in the underlying inflammatory process underlying atherosclerosis.

The effect of increased dietary fruit and vegetable consumption on endothelial activation, inflammation and oxidative stress in hypertensive volunteers

“…When 112 volunteers at increased cardiovascular risk were randomised to a low-fat or Mediterranean diet for 3 months, significantly reduced concentrations of plasma sICAM-1 and sVCAM-1 were observed in the latter group [35]. Investigators have also reported down-regulation of these adhesion molecules following 4 week red wine [36] and 8 week soy nut interventions [37]. Such positive findings contrast with those reported here and may be related to a number of factors.…”

Flavonoids as anti-inflammatory agents

“…Long-term intervention studies conducted using soya as a source of bioactive molecules showed reduction in levels of vascular cell adhesion molecule-1 and CRP (59,60) , but also a lack of effect on CRP (61)(62)(63) , TNFa (61,63) and IL-6 (60,62) . Increases in total isoflavones, genistein and daidzein (59) and genistein levels (63) induced by long-term soya consumption were not associated with CRP reductions (59,63) .…”

Effects of Equol on Oxidized Low-Density Lipoprotein-Induced Apoptosis in Endothelial Cells

“…The pathophysiological effects of OX-LDL on vascular cells have been well documented; recently, studies have reported that various components in foods can attenuate lipid oxidation [22][23][24][25] . Dietary isoflavones have been suggested to be protective against a range of diseases, including cardiovascular diseases, osteoporosis, and cancer, and have also been reported to alleviate menopausal symptoms in postmenopausal women [26][27][28] . Isoflavones (members of the class of flavonoids) belong to a group of plant compounds called phytoestrogens.…”

“…Isoflavones are also an important class of phytoestrogens, which are found at extremely high levels in soy. Recently, the isoflavones daidzein and genistein have been shown to have beneficial physiological effects on cardiovascular disease, blood pressure and angiogenesis [8][9][10][11][12] . More recently, however, attention has shifted to isoflavone metabolites.…”