Effect of Dietary Protein Source on Calcium Metabolism

This study has been completed.
Sponsor:
Collaborator:
Information provided by (Responsible Party):
University of California, San Francisco
ClinicalTrials.gov Identifier:
NCT00187538
First received: September 13, 2005
Last updated: August 20, 2014
Last verified: August 2014
  Purpose

Osteoporosis is a major health concern worldwide. While there are drugs available for the treatment and prevention of osteoporosis, they are not practical for population-wide prevention efforts. Demonstrating the effectiveness of safe and widely available dietary interventions to prevent osteoporosis could have important public health ramifications. Different food sources of dietary protein may have different effects on bone metabolism. Animal foods provide a dietary acid load that may lead to negative calcium balance and increased bone resorption. In contrast, vegetable sources of protein, while providing some acid due to their protein content, provide proportionally more base that counters the dietary acid load. The effect of dairy products, which are rich in animal protein but also contain potential base precursors not found in vegetable foods, has not been established. Finally, soy protein sources may have a dual benefit: soy foods provide base precursors as well as plant estrogens that may have a beneficial effect on bone. We are resubmitting this proposal to randomize postmenopausal women to one of four diets equal in calories, protein, calcium, and sodium. The diets will differ by having 80 percent of the protein from one of four sources: non-dairy animal, vegetable, dairy, or soy foods, resulting in significant differences among the diets in acid, base, and isoflavone content. All food will be prepared and provided by the General Clinical Research Center. The subjects will consume the diets for 6 weeks with measurements of acid-base status, isoflavone excretion, and calcium metabolism. This will be the first intervention study to examine the effect of different sources of dietary protein in whole foods on calcium metabolism. Eventually our findings could have substantial public health implications and provide a widely available and low risk means to help prevent osteoporosis.


Condition Intervention
Calcium Metabolism
Behavioral: Dietary

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Effect of Dietary Protein Source on Calcium Metabolism

Resource links provided by NLM:


Further study details as provided by University of California, San Francisco:

Primary Outcome Measures:
  • calcium metabolism [ Time Frame: after 8 weeks of diet ] [ Designated as safety issue: No ]

Enrollment: 183
Study Start Date: February 2002
Study Completion Date: July 2013
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1 Behavioral: Dietary
dietary
Active Comparator: 2 Behavioral: Dietary
dietary
Active Comparator: 3 Behavioral: Dietary
dietary
Active Comparator: 4 Behavioral: Dietary
dietary

Detailed Description:

Demonstrating the effectiveness of safe and widely available dietary interventions to prevent osteoporosis could have important public health ramifications. Different food sources of dietary protein may have different effects on bone metabolism. Animal foods provide a dietary acid load that may lead to negative calcium balance and increased bone resorption. In contrast, vegetable sources of protein, while providing some acid due to their protein content, provide proportionally more base that counters the dietary acid load. The effect of dairy products, which are rich in animal protein but also contain potential base precursors not found in vegetable foods, has not been established. Finally, soy protein sources may have a dual benefit: soy foods provide base precursors as well as plant estrogens that may have a beneficial effect on bone. We are resubmitting this proposal to randomize postmenopausal women to one of four diets equal in calories, protein, calcium, and sodium. The diets will differ by having 80 percent of the protein from one of four sources: non-dairy animal, vegetable, dairy, or soy foods, resulting in significant differences among the diets in acid, base, and isoflavone content. All food will be prepared and provided by the General Clinical Research Center. The subjects will consume the diets for 6 weeks with measurements of acid-base status, isoflavone excretion, and calcium metabolism. This will be the first intervention study to examine the effect of different sources of dietary protein in whole foods on calcium metabolism. Eventually our findings could have substantial public health implications and provide a widely available and low risk means to help prevent osteoporosis.

  Eligibility

Ages Eligible for Study:   55 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

Healthy postmenopausal women

Exclusion Criteria:

No meds affecting bone Normal renal, GI, hepatic function

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00187538

Locations
United States, Maryland
Johns Hopkins University
Baltimore, Maryland, United States, 21224
Sponsors and Collaborators
University of California, San Francisco
Investigators
Principal Investigator: Deborah Sellmeyer, MD Johns Hopkins University
  More Information

No publications provided

Responsible Party: University of California, San Francisco
ClinicalTrials.gov Identifier: NCT00187538     History of Changes
Other Study ID Numbers: H9291-19207-05
Study First Received: September 13, 2005
Last Updated: August 20, 2014
Health Authority: United States: Federal Government

ClinicalTrials.gov processed this record on October 19, 2014