Related Experiment Videos
Dietary soy protein and estrogen replacement therapy improve cardiovascular risk factors and decrease aortic
J D Wagner1, W T Cefalu, M S Anthony
1Comparative Medicine Clinical Research Center, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1040, USA.
Metabolism: Clinical and Experimental
|June 1, 1997
Summary
Dietary soy protein and estrogen replacement therapy (ERT) both benefit cardiovascular health in monkeys. Soy protein improved lipids and insulin sensitivity, while ERT reduced body weight and abdominal fat, with combined use yielding the greatest arterial cholesterol reduction.
Area of Science:
- Cardiovascular Science
- Endocrinology
- Nutritional Science
Background:
- Estrogen replacement therapy (ERT) is known to slow coronary artery atherosclerosis progression.
- Dietary soy protein, containing phytoestrogens, also shows potential in retarding atherosclerosis compared to animal proteins.
- The cardioprotective mechanisms of soy protein and its interaction with estrogen require further elucidation.
Purpose of the Study:
- To investigate the effects of dietary soy protein isolate versus casein/lactalbumin on cardiovascular risk factors in ovariectomized monkeys.
- To determine the impact of 17 beta-estradiol (E2) treatment on these risk factors.
- To examine the combined effects and interactions of soy protein and E2 on cardiovascular risk.
Main Methods:
- A 2x2 factorial study design was employed with ovariectomized female monkeys.
- Animals were fed either soy protein isolate or casein/lactalbumin, with or without E2 supplementation, for 7 months.
- Cardiovascular risk factors, including plasma lipids, insulin sensitivity, glucose effectiveness, and arterial lipid peroxidation, were assessed.
Main Results:
- Soy protein consumption significantly improved plasma lipid profiles, insulin sensitivity, and reduced arterial lipid peroxidation compared to casein.
- E2 treatment led to reduced body weight, abdominal fat, fasting insulin, and smaller LDL particles, with significant reduction in aortic cholesteryl ester content.
- A significant interaction between soy protein and E2 was observed, with the combination resulting in the lowest arterial cholesteryl ester content.
Conclusions:
- Both ERT and dietary soybean protein exert beneficial effects on cardiovascular risk factors in monkeys.
- These interventions target distinct risk factors, and their combined administration provides synergistic benefits, particularly in reducing arterial cholesterol.
- Further research is warranted to identify the active components in soy protein and assess long-term systemic effects.