Soy and Isoflavones Effect on Bone

Soy Proteins and Isoflavones Impact Bone Mineral Density in Older Women

The purpose of this study is to test the effect of 1 year of added dietary soy protein and/or soy isoflavones on bone mineral density in late postmenopausal women.

Study Overview

• Status: Completed
• Conditions: Osteoporosis
• Intervention / Treatment: Dietary supplement: Soy Isolate; Dietary supplement: Novasoy isoflavones; Dietary supplement: Placebo tablets; Dietary supplement: Control protein

Detailed Description

Although soy foods contain several components (isoflavones and amino acids) that could potentially have positive effects on bone health, there are few long term, large, clinical trials using soy as a means of improving bone mineral density. The objective of this study is to provide daily soy protein and isoflavones to healthy older women in order to answer three major questions:

1. Does soy protein alone affect bone metabolism?
2. Do isoflavones, given with soy protein, affect bone metabolism?
3. What dose of isoflavones affects bone in older women?

We hypothesize that soy protein will have a beneficial effect on bone in older women compared to control protein. Further, we hypothesize that there will be an additional benefit to bone in women who receive soy protein plus isoflavones (at both doses) compared to soy protein alone.

Both control and soy proteins used in the study were isolates, meaning they were the highest concentration of protein (85-90% by weight) in order to minimize the volume of protein supplement that each woman was asked to ingest on a daily basis. The soy protein was an alcohol-washed, soy protein isolate containing 90% protein and negligible isoflavone (0.2 mg/g product). The control protein was a mix consisting of 50% protein from sodium caseinate, 25% protein from whey protein and 25% from egg white protein. The use of a mix of proteins as a control provides a more balanced level of amino acids, mimics the real life mix of proteins that humans typically consume, and avoids the unique characteristics of one source of protein. In order to maintain the dietary protein intake constant, the participant was counseled to decrease her intake of other sources of protein from primarily animal sources by approximately 3 ounces per day (the approximate equivalent of the protein powders). The isoflavones tablets each contained 57 mg of total isoflavone from primarily genistein, glycitein, and daidzein and their beta-glycosides.

• Study Type: Interventional
• Enrollment (Actual): 97
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Connecticut
    • Farmington, Connecticut, United States, 06030
      • University of Connecticut Health Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Postmenopausal women 65 years old or older
• Able to travel to the clinical sites for follow-up visits

Exclusion Criteria:

• History of disease that may affect bone metabolism (including Paget's disease, primary hyperparathyroidism, osteomalacia, untreated hyperthyroidism, or multiple myeloma)
• Cancer of any kind (except basal or squamous cell of skin) in past 5 years
• Use of any of the following medications within the past 2 years: calcitonin, calcitriol, heparin, phenytoin, phenobarbital
• Use at any time of bisphosphonates, long-term corticosteroids (over 6 months), methotrexate, or fluoride
• Estimated creatinine clearance less than 50 ml/min
• History of chronic liver disease or evidence of liver disease on screening
• History of hip fracture
• Known vertebral fracture within the past year
• Vegans

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: Triple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 1; Soy protein and isoflavone tablets	Dietary supplement: Soy Isolate; 20 grams of powder mixed in beverages or food daily for one year; Other Names: Pro Fam 930, 066-930; Dietary supplement: Novasoy isoflavones; 3 tablets daily for one year
Active Comparator: 2; Soy protein and placebo tablets	Dietary supplement: Soy Isolate; 20 grams of powder mixed in beverages or food daily for one year; Other Names: Pro Fam 930, 066-930; Dietary supplement: Placebo tablets; 3 tablets daily for one year
Active Comparator: 3; control protein and Isoflavone tablets	Dietary supplement: Novasoy isoflavones; 3 tablets daily for one year; Dietary supplement: Control protein; 20 grams of powder mixed in beverages or food daily for one year
Placebo Comparator: 4; control protein and placebo tablets	Dietary supplement: Placebo tablets; 3 tablets daily for one year; Dietary supplement: Control protein; 20 grams of powder mixed in beverages or food daily for one year

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Bone turnover markers	baseline, 3 months, and 1 year

Secondary Outcome Measures

Outcome Measure	Time Frame
Bone Mineral Density	Baseline, 6 and 12 months
Quality of life measured by Medical Outcomes Short Form	Baseline, 6 and 12 months
Medication Side Effects	3 , 6, 9, and 12 months
Adherence to dietary intervention through the use of 24-hour recall	3, 6, 9, and 12 months
Long-term medication behavior self-efficacy scale	3, 6, 9, and 12 months

Collaborators and Investigators

• Sponsor: United States Department of Agriculture (USDA)
• Collaborators: University of Connecticut
• Investigators: Principal Investigator: Jane Kerstetter, PhD, Department of Allied Health Sciences, University of Connecticut

Publications and helpful links

General Publications

• Evans EM, Racette SB, Van Pelt RE, Peterson LR, Villareal DT. Effects of soy protein isolate and moderate exercise on bone turnover and bone mineral density in postmenopausal women. Menopause. 2007 May-Jun;14(3 Pt 1):481-8. doi: 10.1097/01.gme.0000243570.78570.f7.
• Alekel DL, Germain AS, Peterson CT, Hanson KB, Stewart JW, Toda T. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. Am J Clin Nutr. 2000 Sep;72(3):844-52. doi: 10.1093/ajcn/72.3.844.
• Arjmandi BH, Lucas EA, Khalil DA, Devareddy L, Smith BJ, McDonald J, Arquitt AB, Payton ME, Mason C. One year soy protein supplementation has positive effects on bone formation markers but not bone density in postmenopausal women. Nutr J. 2005 Feb 23;4:8. doi: 10.1186/1475-2891-4-8.
• Kenny AM, Mangano KM, Abourizk RH, Bruno RS, Anamani DE, Kleppinger A, Walsh SJ, Prestwood KM, Kerstetter JE. Soy proteins and isoflavones affect bone mineral density in older women: a randomized controlled trial. Am J Clin Nutr. 2009 Jul;90(1):234-42. doi: 10.3945/ajcn.2009.27600. Epub 2009 May 27.

Study record dates

Study Major Dates

• Study Start: November 1, 2001
• Primary Completion (Actual): June 1, 2005
• Study Completion (Actual): June 1, 2005

Study Registration Dates

• First Submitted: April 25, 2008
• First Submitted That Met QC Criteria: April 25, 2008
• First Posted (Estimate): April 29, 2008

Study Record Updates

• Last Update Posted (Estimate): April 29, 2008
• Last Update Submitted That Met QC Criteria: April 25, 2008
• Last Verified: April 1, 2008

More Information

Terms related to this study

• Keywords: bone density; postmenopausal; bone loss
• Additional Relevant MeSH Terms: Metabolic Diseases; Musculoskeletal Diseases; Bone Diseases; Bone Diseases, Metabolic; Osteoporosis
• Other Study ID Numbers: AG0102; USDA CONR-2001-00630