Macula; DegenerationNCT06349304
Impact of Grape Powder Consumption on Eye Health and Glycemic Status in Singapore Older Adults
A study testing Freeze-dried table grape powder in people with Macula; Degeneration and Aging, run by National University of Singapore at 1 site in Singapore.
Trial summary
The purpose of this study is to understand the impacts of regular consumption of freeze-dried table grape powder on eye health and regulation of advanced glycation end products in Singapore older adults. Read more about this study
- Who is it for?
- Ages 60 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Macula; Degeneration, Aging, Advanced Glycation End Products
- What is being tested?
- Freeze-dried table grape powder
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 46 participants
- Where
- 1 siteSingapore
- Study dates
- 30 Sep 2024to 1 Aug 2025
- 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 60 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male and female participants, aged between 60 and 85 years old inclusive
- English-literate and able to give informed consent in English
Who cannot join
- Smokers
- Allergy to grapes or food dyes/additives, or had serious food allergies in the past
- Known eye diseases (macular degeneration, cataracts, retinopathy or glaucoma), blindness in at least one eye or have had eye surgery
- Unable to view bright lights or flashing lights
- Has Type 1 or 2 diabetes, uremia, cardiovascular disease, abnormal kidney and liver function
- Taking eye medication and/or dietary supplements for the eyes for the past 3 month
Show all 15Show fewer
- Taking supplements containing carotenoids (e.g. Vitamin A, lutein, zeaxanthin) for past 3 months
- Currently on a specialised diet (e.g. vegetarian, vegan, weight loss diet, low fat diet
- Consumes more than 2 alcoholic drinks per day i.e. one drink is defined as either 150ml of wine,340ml of beer/cider or 45ml of distilled spirit
- Significant change in weight (≥ 3 kg body weight) in the past 3 months
- Significant exercise pattern over the past 3 months defined as high-intensity exercise of more than 3 hours per week
- Currently on anti-hypertensive, cholesterol-lowering or psychoactive drugs
- Scored ≤ 7 on the abbreviated mental test
- Poor peripheral venous access based on past experiences with blood draw
- Participating in another clinical study
Trial locations and contacts
1 site in 1 country.
Singapore1 site, 1 recruiting
- Recruiting
National University of Singapore, Faculty of Science, Department of Food Science and Technology
Singapore, Singapore, 117550
Marcus Ting, BSc (Hons) Science, +6597851245, marcusting2702@gmail.com
About this study
Official title: Impact of Regular Consumption of Grape on Eye Health and Regulation of Advanced Glycation End-products in Singapore Older Adults
The purpose of this study is to understand the impacts of regular consumption of freeze-dried table grape powder on eye health and regulation of advanced glycation end products in Singapore older adults. The investigators hypothesize that regular consumption of freeze-dried table grape powder will promote improvements in eye health and lower levels of advanced glycation end products when compared to the placebo group.
Read the detailed description
The study will be a 16-week, double-blind, randomized, placebo-controlled trial using a parallel study design. 46 adults (aged 60 - 85) will be recruited and randomly assigned to the intervention or placebo group to investigate whether regular consumption of freeze-dried table grape powder (46g/d) can improve eye health parameters, blood/skin AGE and glycemic status, and reduce inflammation and oxidative stress. This study will consist of 1 screening visit and 5 study visits with 4-week intervals.
- Conditions
- Macula; Degeneration, Aging, Advanced Glycation End Products
- Being tested
- Freeze-dried table grape powder, Placebo grape powder
- Keywords
- Vitis vinifera, Older adults, Inflammation, Glycemic status, Oxidative stress, Eye health
- Medical subject headings
- Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Freeze-dried table grape powderDietary supplement
Consumption of grape powder as part of daily diet
Placebo grape powderDietary supplement
Consumption of placebo grape powder as part of daily diet
| Study group | Role | What they receive |
|---|---|---|
| Freeze-dried table grape powder | Experimental | Subjects in this group will be given pouches, each containing 46 g of freeze-dried table grape powder, with an instruction sheet on how to prepare the powder into a drink for consumption.They will consume one pouch a day. Receives: Dietary Supplement: Freeze-dried table grape powder |
| Placebo table grape powder | Placebo comparator | Subjects in this group will be given pouches, each containing 46 g of placebo grape powder, with an instruction sheet on how to prepare the powder into a drink for consumption.They will consume one pouch a day. Receives: Dietary Supplement: Placebo grape powder |
What is being measured
The primary outcome is the main question the study is designed to answer.
Macular pigment optical density
A measurement of macular pigment of the eye using a heterochromatic flicker photometry device. The measurements are in arbitrary units.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Visual acuity
Participants will read out letters on a ETDRS LogMAR chart at a fixed distance where letters becomes smaller as it goes down the chart. Tests results will be recorded in number of letters read, where the more letters the better the outcome.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Photostress recovery time
An ophthalmoscope will be used to shine a light into the participants eye for 10 seconds, and participants will be required to read letters off a chart the moment their vision returns to normal. The faster the recovery time, the better the outcome. Units will be in seconds
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Visual function questionnaire 25
A questionnaire to for participants to self-evaluate their perception of their current eye health based on general vision, ocular pain, near activities, distance activities, vision specific functions, driving, color vision and peripheral vision. The best possible score is 100 and worst possible score is 0.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Skin advanced glycation end products levels
Measurement of skin advanced glycation end products level using a skin autofluorescence device, where participants wlll be instructed to place their forearm over the device and a light will be shone and a reading can be captured by detecting fluorescence. The results will be presented as arbitrary units.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Dietary advanced glycation end products level
Participants will be instructed to record down 3-day food records, from Thursday to Saturday, before each clinical visit. This will be used to estimate their advanced glycation end products intake from food by referring to existing nutrient databases. Units will be based on a common advanced glycation end product measured, carboxymethyllysine (CML), thus the unit will be mg CML/ kg food
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Blood advanced glycation end products levels
Participants will have their blood drawn by medical professionals at the Occupational Health Clinic. The blood will be processed and stored. Measurements will be done using ultra-performance liquid chromatography coupled with mass spectrometry techniques to determine the levels of advanced glycation end products. Units will be in μg/mL.
Measured: Week 0, Week 8 and Week 16
Contrast sensitivity
Participants will read out letters on a ETDRS LogMAR chart at a fixed distance, where the letters differs in lightness to test participants' sensitivity to contrast. Tests results will be recorded in number of letters read, where the more letters the better the outcome.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16
Secondary outcomes (9)
Concentration of tumour necrosis factor-α
The blood obtained from the participants will be processed for storage. Tumor necrosis factor-α results will be presented in ng/L according to the commercially available enzyme-linked immunosorbent assay kits.
Measured: Week 0, Week 8, Week 16
Concentration of interleukin-6
The blood obtained from the participants will be processed for storage. Interleukin-6 results will be presented in ng/L according to the commercially available enzyme-linked immunosorbent assay kits.
Measured: Week 0, Week 8, Week 16
Concentration of high-sensitivity C-reactive protein
The blood obtained from the participants will be processed for storage. Analyses of inflammation markers include tumor necrosis factor-α, interleukin-6. high sensitivity C-reactive protein. Tumor necrosis factor-α and interleukin-6 results will be presented in ng/L according to the commercially available enzyme-linked immunosorbent assay kits. High-sensitivity C-reactive protein results will be obtained and presented in mg/L by commercial lab testing.
Measured: Week 0, Week 8, Week 16
Concentration of fasting blood glucose
Fasting blood glucose will be measured using commercial lab testing using participants' blood, units will be in mmol/L.
Measured: Week 0, Week 8, Week 16
Concentration of malondialdehyde
The blood obtained from the participants will be processed for storage. Analyses of malondialdehyde using commercially available enzyme-linked immunosorbent assay kits. Units for malondialdehyde will be in ng/L according to assay kit instructions.
Measured: Week 0, Week 8, Week 16
Concentration of 8-isoprostaglandin-F2α
The blood obtained from the participants will be processed for storage. Analyses of 8-isoprostaglandin-F2α using commercially available enzyme-linked immunosorbent assay kits. Units for 8-isoprostaglandin-F2α will be in µmol/L according to assay kit instructions.
Measured: Week 0, Week 8, Week 16
Skin carotenoid status
Measured using a commercially available device that measured carotenoids using Raman spectroscopy. Results are in arbitrary units.
Measured: Week 0, Week 4, Week 8, Week 12, Week 16;
Concentration of insulin
Fasting blood insulin will be measured using commercial lab testing using participants' blood, units in μU/L.
Measured: Week 0, Week 8, Week 16
Percentage of glycated hemoglobin
Glycated hemoglobin will be measured using commercial lab testing from participant's blood, units in percent.
Measured: Week 0, Week 8, Week 16
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Apr 2024
- Study start30 Sep 2024
- Primary completion1 Aug 2025 (estimated)
- Study completion1 Aug 2025 (estimated)
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 Macula; DegenerationStudies of the same condition, open and under way.
- More trials run by National University of SingaporeThe sponsor's other registered studies.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 46 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National University of Singapore
- Sponsor type
- University, hospital or other
- Collaborators
- California Table Grape Commission
- Responsible party
- Principal investigator, Jung Eun Kim, National University of Singapore
- Investigators
- Jung Eun Kim, Ph.D., R.D., Principal investigator, National University of Singapore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06349304
- Sponsor's protocol ID
- S25
- Status last verified
- Apr 2024
- First submitted
- 14 Mar 2024
- Last updated
- 14 Nov 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Electronic copies of the data with identifiable participant information will be kept on NUS OneDrive with access limited only Dr Kim Jung Eun and her research staff. All data will be de-identified prior to statistical analyses.
Publications
Hu W, Zheng R, Feng Y, Tan D, Chan Chung-Tsing G, Su X, Kim JE. Impacts of regular consumption of grapes on macular pigment accumulation in Singapore older adults: a randomized controlled trial. Food Funct. 2023 Sep 19;14(18):8321-8330. doi: 10.1039/d3fo02105j.
PubMed 37605542
Study at a glance
From the registry record, last updated by the sponsor on 14 Nov 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Regular Consumption of Grape on Eye Health and Regulation of Advanced Glycation End-products in Singapore Older Adults
- ClinicalTrials.gov ID
- NCT06349304
- Acronym / sponsor ID
- S25
- Conditions
- Macula; Degeneration, Aging, Advanced Glycation End Products
- Keywords
- Vitis vinifera, Older adults, Inflammation, Glycemic status, Oxidative stress, Eye health
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 46 participants (estimated)
- Lead sponsor
- National University of SingaporeUniversity, hospital or other
- Collaborators
- California Table Grape Commission
- Study start
- 30 Sep 2024 (actual)
- Primary completion
- 1 Aug 2025 (estimated)
- Study completion
- 1 Aug 2025 (estimated)
- First posted
- 5 Apr 2024 (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.
The purpose of this study is to understand the impacts of regular consumption of freeze-dried table grape powder on eye health and regulation of advanced glycation end products in Singapore older adults. The investigators hypothesize that regular consumption of freeze-dried table grape powder will promote improvements in eye health and lower levels of advanced glycation end products when compared to the placebo group.
Detailed description
The study will be a 16-week, double-blind, randomized, placebo-controlled trial using a parallel study design. 46 adults (aged 60 - 85) will be recruited and randomly assigned to the intervention or placebo group to investigate whether regular consumption of freeze-dried table grape powder (46g/d) can improve eye health parameters, blood/skin AGE and glycemic status, and reduce inflammation and oxidative stress. This study will consist of 1 screening visit and 5 study visits with 4-week intervals.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Freeze-dried table grape powder | Experimental | Dietary Supplement: Freeze-dried table grape powderSubjects in this group will be given pouches, each containing 46 g of freeze-dried table grape powder, with an instruction sheet on how to prepare the powder into a drink for consumption.They will consume one pouch a day. |
| Placebo table grape powder | Placebo comparator | Dietary Supplement: Placebo grape powderSubjects in this group will be given pouches, each containing 46 g of placebo grape powder, with an instruction sheet on how to prepare the powder into a drink for consumption.They will consume one pouch a day. |
Who may qualify
- Ages
- 60 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Male and female participants, aged between 60 and 85 years old inclusive
- English-literate and able to give informed consent in English
Key exclusion criteria (15 listed)
- Smokers
- Allergy to grapes or food dyes/additives, or had serious food allergies in the past
- Known eye diseases (macular degeneration, cataracts, retinopathy or glaucoma), blindness in at least one eye or have had eye surgery
- Unable to view bright lights or flashing lights
- Has Type 1 or 2 diabetes, uremia, cardiovascular disease, abnormal kidney and liver function
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 |
|---|---|---|
| Freeze-dried table grape powderConsumption of grape powder as part of daily diet | Dietary supplement | Freeze-dried table grape powder |
| Placebo grape powderConsumption of placebo grape powder as part of daily diet | Dietary supplement | Placebo table grape powder |
Primary outcome
Macular pigment optical density
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
A measurement of macular pigment of the eye using a heterochromatic flicker photometry device. The measurements are in arbitrary units.
Visual acuity
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
Participants will read out letters on a ETDRS LogMAR chart at a fixed distance where letters becomes smaller as it goes down the chart. Tests results will be recorded in number of letters read, where the more letters the better the outcome.
Photostress recovery time
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
An ophthalmoscope will be used to shine a light into the participants eye for 10 seconds, and participants will be required to read letters off a chart the moment their vision returns to normal. The faster the recovery time, the better the outcome. Units will be in seconds
Visual function questionnaire 25
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
A questionnaire to for participants to self-evaluate their perception of their current eye health based on general vision, ocular pain, near activities, distance activities, vision specific functions, driving, color vision and peripheral vision. The best possible score is 100 and worst possible score is 0.
Skin advanced glycation end products levels
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
Measurement of skin advanced glycation end products level using a skin autofluorescence device, where participants wlll be instructed to place their forearm over the device and a light will be shone and a reading can be captured by detecting fluorescence. The results will be presented as arbitrary units.
Dietary advanced glycation end products level
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
Participants will be instructed to record down 3-day food records, from Thursday to Saturday, before each clinical visit. This will be used to estimate their advanced glycation end products intake from food by referring to existing nutrient databases. Units will be based on a common advanced glycation end product measured, carboxymethyllysine (CML), thus the unit will be mg CML/ kg food
Blood advanced glycation end products levels
Time frame: Week 0, Week 8 and Week 16
Participants will have their blood drawn by medical professionals at the Occupational Health Clinic. The blood will be processed and stored. Measurements will be done using ultra-performance liquid chromatography coupled with mass spectrometry techniques to determine the levels of advanced glycation end products. Units will be in μg/mL.
Contrast sensitivity
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16
Participants will read out letters on a ETDRS LogMAR chart at a fixed distance, where the letters differs in lightness to test participants' sensitivity to contrast. Tests results will be recorded in number of letters read, where the more letters the better the outcome.
9 secondary outcomes
Concentration of tumour necrosis factor-α
Time frame: Week 0, Week 8, Week 16
Concentration of interleukin-6
Time frame: Week 0, Week 8, Week 16
Concentration of high-sensitivity C-reactive protein
Time frame: Week 0, Week 8, Week 16
Concentration of fasting blood glucose
Time frame: Week 0, Week 8, Week 16
Concentration of malondialdehyde
Time frame: Week 0, Week 8, Week 16
Concentration of 8-isoprostaglandin-F2α
Time frame: Week 0, Week 8, Week 16
Skin carotenoid status
Time frame: Week 0, Week 4, Week 8, Week 12, Week 16;
Concentration of insulin
Time frame: Week 0, Week 8, Week 16
Percentage of glycated hemoglobin
Time frame: Week 0, Week 8, Week 16
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 Nov 2024.
- Background: PubMed 37605542Hu W, Zheng R, Feng Y, Tan D, Chan Chung-Tsing G, Su X, Kim JE. Impacts of regular consumption of grapes on macular pigment accumulation in Singapore older adults: a randomized controlled trial. Food Funct. 2023 Sep 19;14(18):8321-8330. doi: 10.1039/d3fo02105j.
- Individual participant dataSharing planned: No. Electronic copies of the data with identifiable participant information will be kept on NUS OneDrive with access limited only Dr Kim Jung Eun and her research staff. All data will be de-identified prior to statistical analyses.
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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.
Jung Eun Kim, Ph.D., R.D. principal investigator
National University of Singapore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Freeze-dried table grape powder in people with Macula; Degeneration and Aging, run by National University of Singapore at 1 site in Singapore.
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 2 inclusion and 15 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: status not confirmed, as of the sponsor's last update on 14 Nov 2024. 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 Singapore. 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. Some participants in this study may receive a placebo. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Marcus Ting (97851245, marcusting@u.nus.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Macular pigment optical density (time frame: Week 0, Week 4, Week 8, Week 12, Week 16). The study lists 8 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 NCT06349304, 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 14 Nov 2024.