Effects of Daily Beef Intake, as a Component of a Heart-Healthy Diet on Cellular Zinc

February 4, 2026 updated by: University of California, Davis

Effects of Daily Beef Intake, as a Component of a Heart-Healthy Diet, on Cellular Zinc Status and Vascular Function in Older Adults

The objective of the current study is to test the overarching hypothesis that the beef nutritive matrix is uniquely suited to direct dietary zinc to cellular compartments for improved metabolic function, leading to a greater effect on health outcomes. Specifically, whether beef, as a component of a healthy meal, will promote the absorption of zinc into cells, where the zinc will have greater effects on zinc-dependent metabolic processes supporting cardiovascular health. To maximize the observability of these beef-related effects, individuals who are 55- to 70-year-old who generally have a higher risk of zinc deficiency and cardiovascular disease will be enrolled.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study will examine whether daily beef intake will promote the absorption of dietary zinc into cells, leading to improved cellular zinc status and microvascular function. The study design will be a crossover comparison of a mixed diet including green leafy vegetables, fruits, whole grains, seeds, and nuts; with beef versus non-meat sources of additional protein and zinc, over two 4-week metabolic study periods.

Outcomes will include cellular zinc status determined by erythrocyte zinc tracer exchange (primary), and microvascular function expressed as reactive hyperemia index (RHI). Previous studies have demonstrated that zinc tracer exchange with red blood cells (RBC) is highly sensitive to changes in zinc nutriture. Thus, cellular zinc status will be determined using a novel and cost-effective adaptation of this approach, modeling zinc tracer exchange with freshly-sampled RBC. As intracellular zinc can regulate vascular tone, microvascular function will be measured, using digital peripheral tonometry, will be used as a functional index of both cellular zinc status and vascular health.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Davis, California, United States, 95616
        • Recruiting
        • University of California, Davis; Department of Nutrition
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

55 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Male or postmenopausal female 55-70 years of age
  • Women: lack of menses for at least two years.
  • Subject is willing and able to comply with the study protocols.
  • Subject is willing to participate in all study procedures
  • Self-reported stable dose of prescribed medications for a minimum of 6 months
  • BMI 18.5 - 29.9 kg/m2

Exclusion Criteria:

  • Self-reported use of daily anticoagulation agents including aspirin, NSAIDs
  • Prescribed metaformin, statins or medications known to interfere with zinc, protein, or lipid metabolism
  • Vegan, Vegetarians, food faddists or those consuming a non-traditional diet (e.g. Adkins, Keto, Paleo, etc.)
  • Fruit consumption ≥ 3 cups/day
  • Regular consumption of strawberries (2-3 servings/week)
  • Vegetable consumption ≥ 4 cups/day
  • Coffee/tea ≥ 3 cups/day
  • Dark chocolate ≥ 3 oz/day
  • Alcohol intake greater than 2 drinks in a day for men, or 1 drink in a day for women.
  • Self-reported restriction of physical activity due to a chronic health condition
  • Self-reported chronic/routine high intensity exercise
  • Self-reported diabetes
  • Blood pressure ≥ 140/90 mm Hg
  • Self-reported renal or liver disease
  • Self-reported heart disease, which includes cardiovascular events and stroke
  • Peripheral artery disease Raynaud's syndrome or disease
  • Inability to properly place or wear the PAT probes or abnormal measurements on pre-screening PAT
  • Self-reported cancer within past 5 years
  • Self-reported malabsorption
  • Unwillingness to stop any supplement use six weeks prior to study initiation, including multivitamin/mineral, powders, herbal, plant or botanical, pro- and prebiotics, and oil supplements.
  • Smoking, vaping, cannabis use
  • Current enrollee in a clinical research study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Beef Protein
A beef stew, providing 8.8 mg zinc, 37.9 mg protein (approximately 500 kcal/d energy);
Other: Beef protein
Animal protein source
Active Comparator: Animal Protein
A control plant protein stew, providing 8.8 mg zinc, 37.9 mg protein (approximately 500 kcal/d energy);
Other: Beef protein
Animal protein source

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
microvascular function
Time Frame: 4 weeks
microvascular function as measured by digital tonometry (EndoPAT2000)
4 weeks
intracellular zinc status
Time Frame: 4 weeks
intracellular zinc status determined by erythrocyte zinc tracer exchange
4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
plasma lipids
Time Frame: 4 weeks
Circulating level of total cholesterol, triglycerides, HDL cholesterol, non-HDL cholesterol, with LDL cholesterol (calculated)
4 weeks
plasma fatty acids
Time Frame: 4 weeks
Circulating levels of non-esterified fatty acids
4 weeks
plasma oxylipins
Time Frame: 4 weeks
enzyme and non-enzyme derived non-esterified fatty acid metabolites
4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, Davis

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Cattlemen's Beef Association, a contractor to the Beef Checkoff

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Carl L Keen, PhD, Distinguished Professor Emeritus of Nutrition

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 2, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 2, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 11, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 4, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 1806393

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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