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Mild Cognitive ImpairmentNCT02082418

Effects of Alpha-lactalbumin Intake on Metabolic and Cognitive Functions in Elderly

A study testing Alpha-lactalbumin, Whey and Casein in people with Mild Cognitive Impairment, run by Texas A&M University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Aging modifies the metabolic pathway of the neurotransmitter serotonin by reducing the synthesis rate and increasing the breakdown rate of serotonin, possibly related to the observed enhanced sensitivity of the serotonergic pathway. Read more about this study

Who is it for?
Ages 55 years and olderHealthy volunteers can take part
Conditions the study is for
Mild Cognitive Impairment
What is being tested?
Alpha-lactalbumin, Whey and Casein
Could I receive a placebo?
No, everyone receives an active treatment
How many people
59 participants
Where
1 siteUnited States
Study dates
2 Apr 2014to 1 Dec 2016
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 55 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Dementia diagnosis
  • Ability to walk, sit down and stand up independently
  • Age 55 years or older
  • Ability to lie in supine or elevated position for 8 hours
  • Willingness and ability to comply with the protocol, including:
  • Adhering to fasting state from 10 pm ± 2h onwards the day prior to each study visit
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  • Healthy male or female according to the investigator's or appointed staff's judgment
  • Ability to walk, sit down and stand up independently
  • Age 55 years or older
  • Ability to lie in supine or elevated position for 8 hours
  • Willingness and ability to comply with the protocol, including:
  • Adhering to fasting state from 10 pm ± 2h onwards the day prior to each study visit

Who cannot join

  • Any condition that may interfere with the definition 'healthy subject' according to the investigator's judgment (for healthy control group only)
  • Failure to give informed consent or Investigator's uncertainty about the willingness or ability of the subject to comply with the protocol requirements
  • Indication of severe cognitive impairment (MOCA score < 17)
  • Established diagnosis of Insulin Dependent Diabetes Mellitus
  • History of untreated metabolic disease(s) including hepatic or renal disorder
  • Presence of acute illness or metabolically unstable chronic illness
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  • Presence of fever within the last 3 days
  • Preplanned surgery of procedures that would interfere with the conduct of the study
  • Any other condition according to the PI or study physician that would interfere with proper conduct of the study / safety of the patient
  • Current alcohol or drug abuse
  • Known allergy to milk or milk products
  • Use of long-term oral corticosteroids or short course of oral corticosteroids 4 weeks preceding first test day
  • Use of protein or amino acid containing nutritional supplements within 5 days of test day
  • (Possible) pregnancy
  • BMI of < 18.5 or ≥ 40 kg/m2
  • Dietary or lifestyle characteristics: When during the period from enrollment to completion of the study (end of test day) any condition is developed, whether causing the subject to not meet inclusion criteria or to meet exclusion criteria, the subject will be excluded from the study

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Texas A&M University

    College Station, Texas, 77843

Other trials in United States

About this study

Official title: Effects of Alpha-lactalbumin on Metabolic and Cognitive Functions in Healthy Older Adults

Aging modifies the metabolic pathway of the neurotransmitter serotonin by reducing the synthesis rate and increasing the breakdown rate of serotonin, possibly related to the observed enhanced sensitivity of the serotonergic pathway. Since serotonin plays a prominent role in neuropsychological functions such as anxiety, mood and memory, the enhanced sensitivity of the serotonergic pathway in aging can probably explain the fact that elderly are more vulnerable to develop cognitive deficits and depressive symptoms.

Serotonin synthesis in brain is regulated by its precursor tryptophan (TRP). Because tryptophan is an essential amino acid, modifying the availability of tryptophan through dietary intake, can directly influence central serotonin metabolism and consequently affective and cognitive processes.

The aim of this study is to test the hypothesis that an acute intake of whey protein with high levels of TRP such as alpha-lactalbumin can stabilize the metabolism of serotonin and subsequently enhance metabolic and cognitive functions in healthy older adults. The acute effects of this dietary protein will be investigated in subjects with mild cognitive impairment (MCI), or dementia, compared to control subjects in order to examine whether healthy older subject with MCI benefit more from the intake of alpha-lactalbumin and/or whey. The investigators will investigate if this meal can optimize serotonin metabolism by elevating plasma TRP levels and plasma TRP appearance and enhance splanchnic TRP extraction. In addition, the effects on mood and cognitive functions will be examined.

Read the detailed description

The study involves for all subjects 3 test days (approximately 8 hours each). On this test day the investigators will examine the acute effects of a protein meal. Subjects will receive a mixture of alpha-lactalbumin and/or whey and/or casein, carbohydrates and amino acid stable isotopes to investigate protein and amino acid kinetics (assigned to alpha-lactalbumin or whey or casein group on test day 1, then switch on test day 2 and 3). The subjects will receive these stable isotopes by infusion in their blood and by oral intake (e.g. simultaneously with protein meal). For study purposes, blood will be drawn approx. 25 times during 8 hours on the test day, altogether about 100-120 ml of blood will be drawn on the test day.

Being tested
Alpha-lactalbumin, Whey, Casein
Keywords
Mild cognitive impairment, Protein digestion, Tryptophan digestion, Cognitive function, Mood, Muscle function, Alpha-lactalbumin
Medical subject headings
Cognitive Dysfunction

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Alpha-lactalbuminDietary supplement

    Subjects will ingest the liquid meal containing alpha-lactalbumin and carbohydrates (0.6 g/kg FFM protein + 0.3 g/kg FFM carbohydrates).

  • WheyDietary supplement

    commercially available whey protein

  • CaseinDietary supplement

    commercially available casein protein

Study groups in NCT02082418
Study groupRoleWhat they receive
HealthyExperimentalhealthy control subjects
Receives: Dietary Supplement: Alpha-lactalbumin; Dietary Supplement: Whey; Dietary Supplement: Casein
MCIExperimentalmild cognitive impariments
Receives: Dietary Supplement: Alpha-lactalbumin; Dietary Supplement: Whey; Dietary Supplement: Casein
DementiaExperimentalestablished diagnosis of dementia
Receives: Dietary Supplement: Alpha-lactalbumin; Dietary Supplement: Whey; Dietary Supplement: Casein

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Net whole-body protein synthesis

    Change in whole-body protein synthesis rate after intake of meal

    Measured: 0, 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210 min post-meal

Secondary outcomes (12)

  1. Citrulline rate of appearance

    Plasma enrichment of citrulline

    Measured: Postabsorptive state during 2 hours

  2. Skeletal and respiratory muscle strength

    Difference in leg strength and fatigue, handgrip strength and fatigue, and inspiratory and expiratory pressure between older adults with and without MCI.

    Measured: 1 day

  3. Cognitive function and mood

    Outcome of neuro-psychological tests in healthy older adults with and without MCI in relation to the tryptophan metabolism

    Measured: Postabsorptive state during 3 hours and change after feeding

  4. Protein digestion after feeding

    Ratio enrichment free phenylalanine versus phenylalanine from protein spirulina

    Measured: 0, 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210 min post-meal

  5. Arginine turnover rate

    Arginine enrichment in plasma

    Measured: Postabsorptive state during 3 hours

  6. Whole body collagen breakdown rate

    Hydroxyproline enrichment in plasma

    Measured: Postabsorptive state during 3 hours

  7. Tryptophan turnover rate

    Tryptophan enrichment in plasma in postabsorptive state and after intake of meal

    Measured: Postabsorptive state during 3 hours and change after feeding

  8. Insulin response to feeding

    Acute change from postabsorptive state after intake of meal

    Measured: During 3 hours after feeding

  9. Fat-free mass

    Characteristics of study subjects

    Measured: Postabsorptive state during 15 min

  10. Myofibrillar protein breakdown rate

    3methylhistidine enrichment in plasma

    Measured: 0, 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210 min post-meal

  11. Glycine rate of appearance

    Glycine enrichment in plasma

    Measured: Postabsorptive state during 3 hours

  12. Taurine turnover rate

    Enrichment of taurine in plasma

    Measured: Postabsorptive state during 3 hours

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted10 Mar 2014 (estimated)
  2. Study start2 Apr 2014
  3. Primary completion1 Dec 2016
  4. Study completion1 Dec 2016

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Supportive care
Allocation
Non-randomised
Intervention model
Crossover
Masking
None (open label)
Enrolment
59 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02082418
Sponsor's protocol ID
2014-0065
Status last verified
Sep 2025
First submitted
6 Mar 2014
Last updated
30 Sep 2025
Results posted
No
Data monitoring committee
No

Publications

  • Huttl VN, Deutz N, Wierzchowska-McNew RA, Ruebush LE, Engelen M. Whole-body and intracellular arginine metabolism in hypertension: role of disease severity and sex. Am J Hypertens. 2026 May 18:hpag047. doi: 10.1093/ajh/hpag047. Online ahead of print.

    PubMed 42149813

  • Yu AK, Deutz NEP, Perez CN, DeWandel S, Ruebush LE, Engelen MPKJ. The acute effects of alpha-lactalbumin intake on tryptophan metabolites and mood in older adults with Mild Cognitive Impairment. Nutr Neurosci. 2026 Feb;29(2):180-194. doi: 10.1080/1028415X.2025.2554359. Epub 2025 Sep 14.

    PubMed 40946231

  • Kang MC, Deutz NEP, Kirschner SK, Engelen MPKJ. Metabolic kinetics and muscle and brain health markers in older adults, and the role of age and presence of chronic morbidities: A large cross-sectional cohort study. Clin Nutr. 2024 Dec;43(12):36-47. doi: 10.1016/j.clnu.2024.10.015. Epub 2024 Oct 11.

    PubMed 39423760

  • Deutz LN, Wierzchowska-McNew RA, Deutz NE, Engelen MP. Reduced plasma glycine concentration in healthy and chronically diseased older adults: a marker of visceral adiposity? Am J Clin Nutr. 2024 Jun;119(6):1455-1464. doi: 10.1016/j.ajcnut.2024.04.008. Epub 2024 Apr 12.

    PubMed 38616018

Questions about this trial

What is this clinical trial studying?

A study testing Alpha-lactalbumin, Whey and Casein in people with Mild Cognitive Impairment, run by Texas A&M University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 12 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 30 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Net whole-body protein synthesis (time frame: 0, 15, 30, 45, 60, 75, 90, 105, 120, 150, 180, 210 min post-meal). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02082418, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Sep 2025.

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