Grass-fed vs 100% Total Mixed Rations-fed whole milk powder on circulating levels of fatty acids and vitamins

ISRCTN	ISRCTN10490434
DOI	https://doi.org/10.1186/ISRCTN10490434
Secondary identifying numbers	FHI3 WMP

Submission date: 24/11/2023
Registration date: 29/11/2023
Last edited: 16/06/2025

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
Recent studies have demonstrated that grass-fed dairy foods (e.g. milk, butter, cream) provide a more favourable nutrient profile in terms of fatty acids and several antioxidants, in comparison to non-grass-fed dairy foods. However, previous studies have explored this in milk and cheese only. This considered, the beneficial effects of grass-fed dairy in the context of whole milk powder (WMP), in comparison to grain-fed WMP are unknown.
This study will explore the effect of grass-fed vs grain-fed WMP on circulating fatty acids, vitamins, and markers of metabolic health in a population of healthy adults aged 20-60 years. This research will help us to further understand how feeding regimes can affect dairy produce with the interest of improving the nutrient profile of dairy foods to improve health outcomes.

Who can participate?
Healthy volunteers aged 20-60 years who are not taking medication for cholesterol, blood pressure or digestion or following a prescribed diet e.g., for weight loss or cholesterol.

What does the study involve?
Following a short screening questionnaire, eligible participants will be asked to proceed with the following:
1. They will complete four visits in total to the UCD volunteer suite, completing two dietary intervention phases (6 weeks each), with a 4-week washout period between.
2. Initial visit – 20 minutes at the UCD Volunteer Suites (body composition measurements and a blood sample by a qualified nurse). Participants will be assigned to one of two test diets. WMP samples will be supplied in portioned packs, with instructions on how to consume daily for 6 weeks.
3. Second visit – this will be a repeat of the initial visit.
4. After the 4-week washout period, participants will return for their 3rd visit and repeat the same protocol as the previous visits. They will then be assigned the second test diet.
5. During each 6-week period – participants will keep records of their dietary intake, including calls with a trained nutritionist.
6. Final visit – this will be a repeat of the previous visits.

What are the possible benefits and risks of participating?
There are no known benefits of taking part. However, participants will be contributing to important research. There may be some slight discomfort in providing blood samples, but this will be done by trained and experienced professionals and will involve a small amount of blood (less than a blood donation). There is also a potential risk of tiredness after giving blood.

Where is the study run from?
Institute of Food and Health at University College Dublin (Ireland)

When is the study starting and how long is it expected to run for?
February 2021 to December 2022

Who is funding the study?
Food for Health Ireland

Who is the main contact?
Prof. Eileen Gibney, eileen.gibney@ucd.ie

Study website

Contact information

Prof EIleen GIbney
Public, Scientific, Principal Investigator

UCD Institute of Food and Health
UCD Centre for Molecular Innovation
Science Centre South
University College Dublin
Belfield
Dublin
D04 V1 W8
Ireland

ORCID ID	0000-0001-9465-052X
Phone	+353 (0)1 7162819
Email	eileen.gibney@ucd.ie

Dr Emma Feeney
Public, Scientific, Principal Investigator

S2.16a Science Centre South
UCD Institute of Food and Health
Belfield
Dublin
D04 V1 W8
Ireland

ORCID ID	0000-0003-3234-6340
Phone	+353 (0)17162247
Email	emma.feeney@ucd.ie

Dr Martina Rooney
Public

UCD Institute of Food and Health
UCD Centre for Molecular Innovation
Science Centre South
University College Dublin
Belfield
Dublin
D04 V1 W8
Ireland

ORCID ID	0000-0002-5450-8737
Phone	None provided
Email	martina.rooney@ucd.ie

Study information

Study design	Single-centre double-blinded randomized controlled crossover trial
Primary study design	Interventional
Secondary study design	Randomised cross over trial
Study setting(s)	University/medical school/dental school
Study type	Other
Participant information sheet	44641_PIS.pdf
Scientific title	Grass-fed vs 100% Total Mixed Rations-fed whole milk powder on circulating levels of fatty acids and vitamins
Study objectives	It is hypothesised that compared to total mixed rations-fed whole milk powder (WMP), grass-fed WMP will increase circulating concentrations of conjugated linoleic acid (CLA), n-3 and n-6 fatty acids.
Ethics approval(s)	Approved 19/01/2022, UCD Office of Research Ethics (UCD Research, Tierney Building, Belfield, Dublin, D04 V1W8, Ireland; +353 (0)1 716 7777; research.ethics@ucd.ie), ref: LS-21-99-OConnor-Gibney
Health condition(s) or problem(s) studied	Healthy adults
Intervention	A two-arm crossover trial, with 6-week intervention arms and a 4-week washout period. Participants were allocated to a sequence of treatment using an online randomisation tool (https://www.sealedenvelope.com). Participants were randomised to receive either 200 g/day of whole milk powder made from 100% grass-fed milk or 200 g/day whole milk powder made from 100% pasture-fed milk for 6 weeks. There was a 4-week washout period before participants received the second treatment. Participants could consume the powder as it is, or reconstitute with water, and participants were provided with recipes to incorporate the whole milk powder into their diet.
Intervention type	Supplement
Primary outcome measure	Circulating levels of CLA, n-3 and n-6 fatty acids measured in blood samples by HPLC at baseline and 6 weeks
Secondary outcome measures	1. Total, HDL and LDL cholesterol, triglyceride and glucose concentrations measured in blood samples using NMR at baseline and 6 weeks 2. Insulin concentrations measured in blood samples using ELISA at baseline and 6 weeks 3. Blood pressure (diastolic and systolic blood pressure) assessed using an electronic blood pressure monitor at baseline and 6 weeks 4. Anthropometry assessed by measuring weight, BMI, body fat % and waist circumference at baseline and 6 weeks 5. Inflammatory markers (hs-CRP, IL2, IL10) assessed by biomarker status at baseline and 6 weeks 6. Antioxidant status (circulating ß-carotene, tocopherol, and retinol) as well as markers of lipid peroxidation biomarker F2-isoprostane assessed by biomarker status at baseline and 6 weeks
Overall study start date	01/02/2021
Completion date	16/12/2022

Eligibility

Participant type(s)	Healthy volunteer
Age group	Adult
Lower age limit	20 Years
Upper age limit	60 Years
Sex	Both
Target number of participants	48
Total final enrolment	54
Key inclusion criteria	1. Healthy, not taking medication for cholesterol, blood pressure or digestion 2. Not following a prescribed diet for any reason (weight loss, cholesterol etc) 3. Free from dairy intolerance/allergy and consume an omnivorous diet 4. Male or female, aged 20 - 60 years
Key exclusion criteria	1. Currently taking prescribed medication 2. Following any specific diet will be ineligible for participation in the study 3. Fatty acid/oil-based dietary supplements e.g., fish oils, omega3/6, and other herbal fatty acid-based supplements - e.g., evening primrose oil
Date of first enrolment	12/04/2022
Date of final enrolment	02/09/2022

Locations

Countries of recruitment

Ireland

Study participating centres

University College Dublin

Food for Health Ireland
Science Centre South
Belfield
Dublin
D04 V1W8
Ireland

Food for Health Ireland

UCD Centre for Molecular Innovation and Drug Discovery
Science Centre South
Belfield
Dublin
D04 V1W8
Ireland

Sponsor information

Food for Health Ireland
Research organisation

UCD Centre for Molecular Innovation and Drug Discovery
Science Centre South
Belfield
Dubin
D04 V1 W8
Ireland

Phone	+353 (0)1 716 2391
Email	fhi@ucd.ie
Website	https://www.fhi.ie/
"ROR"	https://ror.org/01nvbq395

Funders

Funder type

Government

Enterprise Ireland
Government organisation / National government

Location: Ireland

Results and Publications

Intention to publish date	30/06/2025
Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not expected to be made available
Publication and dissemination plan	Planned publication in high-impact peer-reviewed journal.
IPD sharing plan	The datasets generated during and/or analysed during the current study are not expected to be made available. The data will be stored on a password-protected computer (encrypted) as per UCD data protection recommendations.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Participant information sheet			28/11/2023	No	Yes
Results article		12/06/2025	16/06/2025	Yes	No

Additional files

44641_PIS.pdf

Editorial Notes

16/06/2025: Publication reference added.
04/06/2024: The intention to publish date was changed from 30/06/2024 to 30/06/2025.
08/03/2024: A study contact was added.
06/03/2024: Sponsor's email address was corrected.
28/11/2023: Study's existence confirmed by the UCD Office of Research Ethics.