Diet, Food Choice, TasteNCT03883880
Salivary Interactions With Chemosensations
A study testing Epigallocatechin gallate, Linoleic acid and Capsaicin solution in people with Diet, Food Choice, Taste, run by Purdue University at 1 site in United States.
Trial summary
A counterbalanced, crossover design will be used to evaluate whether exposure to flavors vs. a control over time alters the perception of the flavor by changing an individual's salivary protein profile. Participants will complete 3 acute tasting protocols (baseline, after intervention 1, after intervention 2). Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Diet, Food Choice, Taste
- What is being tested?
- Epigallocatechin gallate, Linoleic acid and Capsaicin solution
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteUnited States
- Study dates
- 5 Jan 2019to 1 Dec 2021
- 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 18 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Agree to maintain current diet throughout intervention
- Agree to inform us if medication use changes during study.
- Willing and able to taste and consume samples, as well as take pictures to document use of the flavor during intervention.
Who cannot join
- Known issues with salivation, taste, or smell
- Taking medications other than birth control
- User of tobacco products or electronic cigarettes within the last 30 days
Trial locations and contacts
1 site in 1 country.
About this study
A counterbalanced, crossover design will be used to evaluate whether exposure to flavors vs. a control over time alters the perception of the flavor by changing an individual's salivary protein profile. Participants will complete 3 acute tasting protocols (baseline, after intervention 1, after intervention 2). The interventions will be with the flavor (epigallocatechin gallate, linolenic acid, capsaicin) or a control, in counterbalanced order, and will involve swishing and swallowing a solution of that sample 5 times per day for two weeks. Each of these flavors will be a separate sub-study.
Read the detailed description
This study is designed to test the relationship between salivary proteins, flavor sensation, and flavor exposure. For this study, we will test the bitterness/astringency of epigallocatechin gallate (EGCG, a polyphenol), the oleogustus (fatty acid taste) of linolenic acid, and the spiciness of capsaicin in conjunction with the concentration of specific salivary proteins (initially: salivary proline rich proteins for EGCG intervention, lipocalin-1 for the other two, but other proteins may be identified in the post-hoc analysis of the salivary proteome). We will test whether higher expression of these specific salivary proteins correlates with lower intensity of these flavors. We will further attempt to confirm the role of these salivary proteins using food-sourced functional analogs for these proteins. We would expect the food-sourced protein to have the same effect on flavor as the salivary protein if our hypotheses about salivary proteins' influence on flavor are correct. Finally, we will also use denatured versions of the food-sourced proteins to again confirm that effects are due to the function of these proteins binding the flavor.
Additionally, we will repeatedly expose individuals to the flavors by having them rinse and swallow solutions of the flavor compounds multiple times per day for two weeks. We will then re-evaluate the sensory ratings and salivary protein profiles. Two weeks of rinsing and swallowing a control solution will be used as a control during this intervention (for each of the flavors of interest).
To collect saliva and establish bitterness/astringency perception, we will use an acute tasting protocol. Participants will rinse with water, then taste and swallow, then taste and expectorate a solution of the flavor of interest. Saliva will be frozen for later proteomic analysis. Next participants will taste solutions of: flavor, flavor with food analog, the flavor with denatured food analog, water, water with the food analog, and water with denatured food analog. The participants will rank these solutions in order from least intense to most intense for the flavor quality of interest (bitterness/astringency for EGCG). After this, participants will taste all 6 samples again, and rate each individually for the intensity of the bitterness/astringency. After a short wait, this tasting and intensity rating will be repeated. All tastings will be done in counterbalanced order, and solutions will be labeled with randomized 3-digit codes.
This acute tasting protocol will be done: at baseline, after 2 weeks on one intervention (repeated tasting of flavor or control), after 2 weeks on the other intervention.
- Conditions
- Diet, Food Choice, Taste
- Being tested
- Epigallocatechin gallate, Epigallocatechin gallate control, Linoleic acid, Linoleic acid control, Capsaicin solution
- Keywords
- diet, food choice, taste
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Epigallocatechin gallateOther
Colored solution prepared with epigallocatechin gallate to be consumed daily for two weeks during the epigallocatechin gallate intervention.
Epigallocatechin gallate controlOther
Colored control solution to be consumed daily for two weeks during the epigallocatechin gallate intervention.
Linoleic acidOther
Colored emulsion prepared with linoleic acid to be consumed daily for two weeks during the linoleic acid intervention.
Linoleic acid controlOther
Colored control solution to be consumed daily for two weeks during the linoleic acid intervention.
Capsaicin solutionOther
Colored solution prepared with capsaicin to be consumed daily for two weeks during the capsaicin intervention.
Capsaicin controlOther
Colored control solution to be consumed daily for two weeks during the capsaicin intervention.
| Study group | Role | What they receive |
|---|---|---|
| Epigallocatechin gallate | Experimental | Epigallocatechin gallate solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. Receives: Other: Epigallocatechin gallate; Other: Epigallocatechin gallate control |
| Linoleic acid | Experimental | Linoleic acid emulsion will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. Receives: Other: Linoleic acid; Other: Linoleic acid control |
| Capsaicin | Experimental | Capsaicin solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. Receives: Other: Capsaicin solution; Other: Capsaicin control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Salivary proteins
Subjects saliva will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). The proteomic composition of the saliva samples will be established, and used to evaluate relationships with other outcome measures.
Measured: 9 months per sub-study (intervention type)
Flavor intensity ratings
Flavor intensities for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rate (in duplicate) the intensity of flavor from the following solutions: flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ratings will be evaluated in context of the timeline of the exposure as well as the salivary proteome.
Measured: 9 months per sub-study (intervention type)
Flavor rankings
Flavor rankings for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rank the following solutions from most to least intense: Flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ranking data will be used an another method to gather information on what solutions are most intense to the subject, as the intensity ratings may have complications due to order effects during tastings. These rankings will also be evaluated in context of the timeline of the exposure as well as the salivary proteome.
Measured: 9 months per sub-study (intervention type)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Mar 2019
- Study start5 Jan 2019
- Primary completion24 Sep 2019
- Study completion1 Dec 2021
Why it stopped: COVID (completed first intervention type only)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Diet, Food Choice, TasteStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Purdue University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institutes of Health (NIH)
- Responsible party
- Principal investigator, Cordelia Running, PhD, Purdue University
- Investigators
- Cordelia Running, PhD, Principal investigator, Purdue University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03883880
- Sponsor's protocol ID
- 082-011
- Status last verified
- May 2023
- First submitted
- 18 Mar 2019
- Last updated
- 25 May 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Davis LA, Running CA. Repeated exposure to epigallocatechin gallate solution or water alters bitterness intensity and salivary protein profile. Physiol Behav. 2021 Dec 1;242:113624. doi: 10.1016/j.physbeh.2021.113624. Epub 2021 Oct 14.
PubMed 34655570
Study at a glance
From the registry record, last updated by the sponsor on 25 May 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Salivary Interactions With Chemosensations
- ClinicalTrials.gov ID
- NCT03883880
- Acronym / sponsor ID
- 082-011
- Conditions
- Diet, Food Choice, Taste
- Keywords
- diet, food choice, taste
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: COVID (completed first intervention type only)
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Purdue UniversityUniversity, hospital or other
- Collaborators
- National Institutes of Health (NIH)
- Study start
- 5 Jan 2019 (actual)
- Primary completion
- 24 Sep 2019 (actual)
- Study completion
- 1 Dec 2021 (actual)
- First posted
- 21 Mar 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A counterbalanced, crossover design will be used to evaluate whether exposure to flavors vs. a control over time alters the perception of the flavor by changing an individual's salivary protein profile. Participants will complete 3 acute tasting protocols (baseline, after intervention 1, after intervention 2). The interventions will be with the flavor (epigallocatechin gallate, linolenic acid, capsaicin) or a control, in counterbalanced order, and will involve swishing and swallowing a solution of that sample 5 times per day for two weeks. Each of these flavors will be a separate sub-study.
Detailed description
This study is designed to test the relationship between salivary proteins, flavor sensation, and flavor exposure. For this study, we will test the bitterness/astringency of epigallocatechin gallate (EGCG, a polyphenol), the oleogustus (fatty acid taste) of linolenic acid, and the spiciness of capsaicin in conjunction with the concentration of specific salivary proteins (initially: salivary proline rich proteins for EGCG intervention, lipocalin-1 for the other two, but other proteins may be identified in the post-hoc analysis of the salivary proteome). We will test whether higher expression of these specific salivary proteins correlates with lower intensity of these flavors. We will further attempt to confirm the role of these salivary proteins using food-sourced functional analogs for these proteins. We would expect the food-sourced protein to have the same effect on flavor as the salivary protein if our hypotheses about salivary proteins' influence on flavor are correct. Finally, we will also use denatured versions of the food-sourced proteins to again confirm that effects are due to the function of these proteins binding the flavor.
Additionally, we will repeatedly expose individuals to the flavors by having them rinse and swallow solutions of the flavor compounds multiple times per day for two weeks. We will then re-evaluate the sensory ratings and salivary protein profiles. Two weeks of rinsing and swallowing a control solution will be used as a control during this intervention (for each of the flavors of interest).
To collect saliva and establish bitterness/astringency perception, we will use an acute tasting protocol. Participants will rinse with water, then taste and swallow, then taste and expectorate a solution of the flavor of interest. Saliva will be frozen for later proteomic analysis. Next participants will taste solutions of: flavor, flavor with food analog, the flavor with denatured food analog, water, water with the food analog, and water with denatured food analog. The participants will rank these solutions in order from least intense to most intense for the flavor quality of interest (bitterness/astringency for EGCG). After this, participants will taste all 6 samples again, and rate each individually for the intensity of the bitterness/astringency. After a short wait, this tasting and intensity rating will be repeated. All tastings will be done in counterbalanced order, and solutions will be labeled with randomized 3-digit codes.
This acute tasting protocol will be done: at baseline, after 2 weeks on one intervention (repeated tasting of flavor or control), after 2 weeks on the other intervention.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Epigallocatechin gallate | Experimental | Other: Epigallocatechin gallate, Other: Epigallocatechin gallate controlEpigallocatechin gallate solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. |
| Linoleic acid | Experimental | Other: Linoleic acid, Other: Linoleic acid controlLinoleic acid emulsion will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. |
| Capsaicin | Experimental | Other: Capsaicin solution, Other: Capsaicin controlCapsaicin solutions will be provided to participants to rinse with daily for two weeks. A control solution will be provided for two weeks as well. Order will be counterbalanced across participants and groups. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Agree to maintain current diet throughout intervention
- Agree to inform us if medication use changes during study.
- Willing and able to taste and consume samples, as well as take pictures to document use of the flavor during intervention.
Key exclusion criteria (3 listed)
- Known issues with salivation, taste, or smell
- Taking medications other than birth control
- User of tobacco products or electronic cigarettes within the last 30 days
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Epigallocatechin gallateColored solution prepared with epigallocatechin gallate to be consumed daily for two weeks during the epigallocatechin gallate intervention. | Other | Epigallocatechin gallate |
| Epigallocatechin gallate controlColored control solution to be consumed daily for two weeks during the epigallocatechin gallate intervention. | Other | Epigallocatechin gallate |
| Linoleic acidColored emulsion prepared with linoleic acid to be consumed daily for two weeks during the linoleic acid intervention. | Other | Linoleic acid |
| Linoleic acid controlColored control solution to be consumed daily for two weeks during the linoleic acid intervention. | Other | Linoleic acid |
| Capsaicin solutionColored solution prepared with capsaicin to be consumed daily for two weeks during the capsaicin intervention. | Other | Capsaicin |
| Capsaicin controlColored control solution to be consumed daily for two weeks during the capsaicin intervention. | Other | Capsaicin |
Primary outcome
Salivary proteins
Time frame: 9 months per sub-study (intervention type)
Subjects saliva will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). The proteomic composition of the saliva samples will be established, and used to evaluate relationships with other outcome measures.
Flavor intensity ratings
Time frame: 9 months per sub-study (intervention type)
Flavor intensities for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rate (in duplicate) the intensity of flavor from the following solutions: flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ratings will be evaluated in context of the timeline of the exposure as well as the salivary proteome.
Flavor rankings
Time frame: 9 months per sub-study (intervention type)
Flavor rankings for the flavor of interest (bitterness/astringency, oleogustus, and spiciness) will be collected at baseline, after the flavor intervention, and after control intervention (two weeks each, order counterbalanced) for each type of intervention (epigallocatechin gallate, linoleic acid, capsaicin). Subjects will rank the following solutions from most to least intense: Flavor in water, flavor in water with food-sourced salivary protein analog, flavor in water with denatured food-sourced salivary protein analog, water, water with food-sourced salivary protein analog , water with denatured food-sourced salivary protein analog. These ranking data will be used an another method to gather information on what solutions are most intense to the subject, as the intensity ratings may have complications due to order effects during tastings. These rankings will also be evaluated in context of the timeline of the exposure as well as the salivary proteome.
Results and safety
The study was stopped early (reason given: COVID (completed first intervention type only)). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 May 2023.
- Derived from this study: PubMed 34655570Davis LA, Running CA. Repeated exposure to epigallocatechin gallate solution or water alters bitterness intensity and salivary protein profile. Physiol Behav. 2021 Dec 1;242:113624. doi: 10.1016/j.physbeh.2021.113624. Epub 2021 Oct 14.
- Individual participant dataSharing planned: Undecided
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Cordelia Running, PhD principal investigator
Purdue University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Epigallocatechin gallate, Linoleic acid and Capsaicin solution in people with Diet, Food Choice, Taste, run by Purdue 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 3 inclusion and 3 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: stopped early, as of the sponsor's last update on 25 May 2023. 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 was stopped early (reason given: COVID (completed first intervention type only)). Results are not available in the source record.
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?
Salivary proteins (time frame: 9 months per sub-study (intervention type)). The study lists 3 primary outcomes in all. 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 NCT03883880, which also lists 1 linked publication.
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 25 May 2023.