Clinical Trial: Soy Nut Study on Markers of Health

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effects of Soy on Metabolite Markers of Health

Brief Summary: The investigators hope to learn about the effects of soy nuts on markers of health. When some people eat soy foods, their gut bacteria make equol. Equol is a soy metabolite (small molecule made during metabolism). The investigators will be testing blood samples to determine if markers of health are different for people who make equol versus people who do not make equol.

Detailed Summary:

The objective of the study is to investigate the metabolomic response to consumption of soy protein containing polyphenolic phytochemicals (isoflavones). The aim of this pilot study is to demonstrate proof of concept and ability to detect metabolomic changes that are responsive to soy. This preliminary data will then be used to design future research projects.

Food phytochemicals such as the polyphenolic flavonoids from a wide variety of foods and beverages have been associated with cardiovascular protective effects in epidemiologic studies. Significant controversy exists in the literature regarding the efficacy and mechanisms for the cardiovascular protection of soy foods. The soy hypothesis for cardiovascular risk reduction has been focused mainly on the isoflavone content of soy, but uncertainty still exists regarding the bioactive component(s). In particular, consumption of soy protein foods has been associated with favorable cardiovascular disease (CVD) risk profiles in population based studies. Controlled clinical trials and meta-analyses however, have resulted in the conclusions that soy protein with associated isoflavones has only modest hypocholesterolemic effects in the range of 3-5% reduction in LDL-cholesterol. Additional cardioprotective effects have been demonstrated in clinical trials, promoting small but significant changes in vascular endothelial function and antioxidant protection. An important observation is that animal studies have shown reduction in atherosclerotic lesion size both with and without decreased blood lipid levels. These results taken together suggest that soy and soy phytochemicals can promote positive risk factors and outcomes by mechanisms in addition to, and other than lowering serum cholesterol levels. There is a need for greater understanding of the cellular and molecular mechanisms underlying the physiologic responses to isoflavone
Sponsor: University of California, Davis

Current Primary Outcome:

  • Improve lipid profile [ Time Frame: After 4 week intervention ]
    Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglyceride level, apolipoproteinA1, apolipoproteinB100, apolipoproteinB100:apolipoproteinA1, urinary F2-isoprostane
  • Increase endothelial function [ Time Frame: After 4 week intervention ]
    Brachial artery flow mediated dilation, reactive hyperemia peripheral arterial tonometry, blood pressure, endothelin-1
  • Attenuate glycemic responses [ Time Frame: After 4 week intervention ]
    Fasting plasma glucose, insulin, fructosamine, homeostasis model assessment of insulin resistance


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Decrease inflammatory markers [ Time Frame: After 4 week intervention ]
    High sensitivity C reactive protein, vascular cell adhesion molecule-1, intercellular adhesion molecule-1
  • Follow anthropometrics for stable weight [ Time Frame: After 4 week intervention ]
    Weight, height, body mass index, waist circumference, hip circumference, waist:hip ratio


Original Secondary Outcome: Same as current

Information By: University of California, Davis

Dates:
Date Received: July 23, 2010
Date Started: August 2010
Date Completion:
Last Updated: September 2, 2015
Last Verified: September 2015