Assessing the Influence of Habitual Beef Intake on Key Molecular Markers of Brain Health

his study investigates whether eating lean beef every day can help support brain health and healthy aging in older adults. As people age, protecting memory and cognitive function becomes increasingly important. Lean beef is a rich source of essential nutrients-such as vitamin B12, iron, zinc, and creatine-that are known to support brain function. However, the direct biological effects of a beef-rich diet on brain health markers are not fully understood.

In this study, researchers will recruit 20 generally healthy older adults (aged 65 and older) to participate in a dietary feeding trial. Participants will complete two separate 2-week dietary phases. During one phase, participants will consume 5.5 ounces (156 grams) of provided lean beef daily. During the other phase, they will consume an iso-caloric, protein-matched, non-beef control food daily. A two-week "washout" period, where participants return to their normal diets, will separate the two phases to ensure there are no overlapping effects.

Researchers will collect blood, urine, stool, and saliva samples at the beginning and end of each 2-week dietary phase. These samples will be analyzed to see if the lean beef diet improves specific biological markers in the blood related to memory, nerve protection, and overall brain aging. Ultimately, the findings from this study will help determine if incorporating lean beef into a regular diet can be a natural, food-based strategy to help preserve neurological health in older adults.

Study Overview

• Status: Recruiting
• Conditions: Healthy Aging; Cardiometabolic Health; Brain Health; Normal Aging; Cognitive Decline Prevention in Robust Older Adults
• Intervention / Treatment: Other: Lean Beef; Other: Non-Beef Control

Detailed Description

Background and Rationale:

Cognitive decline and related dementias represent a growing public health crisis. While age and genetics are immutable risks, diet is a key modifiable factor for prevention and resilience. Lean beef provides a unique nutrient matrix-including vitamin B12, heme iron, zinc, selenium, creatine, and choline-that may support multiple aspects of brain structure and function. Recent advances in blood-based biomarkers now allow for the sensitive detection of neuropathological processes and neuroplasticity in response to lifestyle interventions. This project seeks to move beyond observational data to uncover the biological mechanisms that confer brain health by assessing the direct molecular impact of a dietary beef intervention.

Study Objectives:

The overarching goal of this study is to determine the impact of regular lean beef consumption on the molecular profile of brain health in healthy older adults. The primary aim is to quantify the within-person change in plasma phosphorylated tau-217 (p-tau217) following a 2-week lean beef intervention compared to a matched non-beef control. Secondary and exploratory aims include measuring within-person changes in the amyloid-beta 42/40 ratio (Aβ42/40) and Brain-Derived Neurotrophic Factor (BDNF), characterizing global shifts in the plasma lipidome, and exploring mechanisms of action via nutrient biomarkers.

Study Design:

The study is designed as a two-arm, randomized, controlled, crossover feeding trial. Twenty generally healthy adults (aged 65 years and older) will be block-randomized (1:1) to begin with either the intervention phase or the control phase.

Intervention Phase: Daily incorporation of 156 grams (5.5 oz) of lean beef for 14 days.

Control Phase: Daily incorporation of an iso-caloric, protein-matched non-beef control for 14 days.

A two-week washout period will separate the two phases to eliminate physiological carryover effects. Assignment of sequence will be randomized and counterbalanced to control for order and seasonal bias. Participants will maintain habitual eating patterns but will replace their daily protein sources with the study-provided food.

Methodology and Data Collection:

Clinical data and biological specimens will be collected at four distinct time points: the baseline and the conclusion of each 14-day dietary phase. At each clinical visit, fasted (12-hour) blood samples, as well as urine, stool, and saliva samples, will be collected. Basic anthropometric measurements, vital signs, and daily dietary records will also be obtained to monitor adherence and physical stability.

Outcome Evaluation and Analysis:

Targeted biomarkers of neurodegeneration and neuroplasticity (p-tau217, Aβ42/40, and BDNF) will be quantified using validated enzyme-linked immunosorbent assays (ELISA). Comprehensive untargeted lipidomic profiling will be conducted via Liquid Chromatography-Mass Spectrometry (LC-MS) workflows to identify lipid signatures associated with the intervention. Primary statistical analyses will utilize linear mixed-effects models to compare within-subject differences between the beef intervention and control conditions, adjusting for sequence and period effects. Appropriate statistical corrections will be applied for multiple comparisons and high-dimensional omics data.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Samitinjaya Dhakal, PhD; Phone Number: 605-688-5465; Email: samitinjaya.dhakal@sdstate.edu

Study Locations

• United States
  • South Dakota
    • Brookings, South Dakota, United States, 57007
      • Recruiting
      • South Dakota State University
      • Contact: Samitinjaya Dhakal; Phone Number: 605-688-5465; Email: samitinjaya.dhakal@sdstate.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Adults aged 65 years and older.

Generally healthy with no acute illnesses.

Fluent in English.

Willing to consume lean beef and dairy products (cottage cheese and whey protein) daily during the intervention phases.

Willing to maintain current, habitual diet, physical activity levels, and body weight throughout the study.

Willing to fast for 12 hours prior to clinical visits and provide blood, urine, stool, and saliva samples.

Exclusion Criteria:

Diagnosed with Alzheimer's disease, Parkinson's disease, or other severe cognitive disorders.

History of gastrointestinal diseases (e.g., Crohn's disease, celiac disease) or major gastrointestinal surgery.

Uncontrolled diabetes, severe liver or kidney disease, or a recent cardiovascular event (within the past 6 months).

Allergies or severe intolerances to beef or dairy, or adherence to a strict vegetarian or vegan diet.

Body weight fluctuation of >5% within the past 3 months.

Use of systemic antibiotics within the 2 months prior to baseline.

Current heavy smoking or excessive alcohol consumption.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lean Beef Intervention; Participants will consume 156 grams (5.5 ounces) of provided lean beef daily for a 14-day period. Participants will be instructed to maintain their habitual dietary patterns otherwise, but will replace a portion of their standard daily protein intake with the study-provided lean beef.	Other: Lean Beef; Participants will be provided with and instructed to consume 156 grams (5.5 ounces) of cooked lean beef daily for 14 days.
Active Comparator: Non-Beef Control; Participants will consume a provided iso-caloric, protein-matched, non-beef control food daily for a 14-day period. Participants will be instructed to maintain their habitual dietary patterns otherwise, but will replace a portion of their standard daily protein intake with the study-provided control food.	Other: Non-Beef Control; Participants will be provided with and instructed to consume an iso-caloric, macronutrient- and protein-matched non-beef control consisting of a mixture of cottage cheese and whey protein daily for 14 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Plasma Phosphorylated Tau-217 (p-tau217) Concentration	Quantitative change in fasting plasma concentrations of p-tau217, a blood-based biomarker indicative of neurodegeneration and cognitive decline. This will be measured using commercially available Enzyme-Linked Immunosorbent Assays	Baseline (Day 0) and End of Intervention (Day 14) for each of the two dietary phases.
Change in Plasma Amyloid-Beta 42/40 (Aβ42/40) Ratio	Quantitative change in the ratio of fasting plasma Aβ42 to Aβ40, a recognized biomarker for early amyloid pathology. This will be measured using commercially available ELISA kits.	Baseline (Day 0) and End of Intervention (Day 14) for each of the two dietary phases.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Shift in Plasma Lipidome Profile	Global shifts in fasting plasma lipid species assessed via comprehensive untargeted lipidomics. Analysis will be conducted using Liquid Chromatography-Mass Spectrometry (LC-MS) workflows to evaluate relative abundance changes in lipid metabolites between the beef and control diets.	Baseline (Day 0) and End of Intervention (Day 14) for each of the two dietary phases.
Change in Gut Microbiome Composition	Alterations in gut microbial diversity and taxonomic relative abundance. This will be assessed via high-throughput sequencing (e.g., 16S rRNA or metagenomics) of DNA extracted from stool samples collected before and after each dietary phase.	Baseline (Day 0) and End of Intervention (Day 14) for each of the two dietary phases.

Collaborators and Investigators

• Sponsor: South Dakota State University

Study record dates

Study Major Dates

• Study Start (Estimated): June 3, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): July 31, 2027

Study Registration Dates

• First Submitted: May 28, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: older adults; nutrition; neuroprotection; dietary intervention; metabolomics; lipidomics; red meat; amyloid beta; brain biomarkers; bdnf; lean beef; p-tau217
• Additional Relevant MeSH Terms: Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms; Plaque, Amyloid
• Other Study ID Numbers: IRB-2026-101

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data (IPD) that underlie the results reported in the peer-reviewed published article will be made available to qualified researchers.
• IPD Sharing Time Frame: Data will become available immediately following the publication of the primary manuscript and will remain accessible for 5 years.
• IPD Sharing Access Criteria: Data will be shared with qualified academic researchers who submit a methodologically sound proposal that has been approved by an independent review committee identified for this purpose. Proposals must be directed to the Principal Investigator. Data will only be shared for the purpose of achieving the aims explicitly outlined in the approved proposal, and a data-sharing agreement must be signed.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No