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Impact of Regular Consumption of Grapes on Eye Health in Singapore Older Adults

Primary Purpose

Eye Health, Age-related Macular Degeneration

Status
Active
Phase
Not Applicable
Locations
Singapore
Study Type
Interventional
Intervention
Freeze-dried table grape powder
Placebo of the table grape powder
Sponsored by
National University of Singapore
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional prevention trial for Eye Health focused on measuring Eye Health, Age-related Macular Degeneration, carotenoids

Eligibility Criteria

60 Years - 85 Years (Adult, Older Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Male and female participants, aged between 60 and 85 years old inclusive
  • Able to give informed consent in English

Exclusion Criteria:

  • Smokers
  • Allergy to grapes
  • Known eye diseases (macular degeneration, cataracts, retinopathy or glaucoma), blindness in at least one eye or have had eye surgery
  • Abnormal kidney and liver function
  • Taking eye medication and/or dietary supplements for the eyes for the past 3 months
  • Taking supplements containing carotenoids (e.g. Vitamin A, lutein, zeaxanthin) for the past 3 months
  • Currently on type 2 diabetic medication.
  • Currently on anti-hypertensive or cholesterol-lowering; unless this prescription has been ongoing for more than 3 years prior to study participation.
  • Currently on a specialized 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
  • Poor peripheral venous access based on past experiences with blood draw
  • Participating in another clinical study

Sites / Locations

  • National University of Singapore

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Placebo Comparator

Arm Label

Freeze-dried table grape powder

Placebo grape powder

Arm Description

The intervention group will consume 46 g/day of a freeze-dried table grape powder.

The control group will consume the same amount of a placebo with a similar taste to the table grape powder.

Outcomes

Primary Outcome Measures

Change in macular pigment optical density
Macular pigment optical density will be measured using macular pigment scanner
Change in skin carotenoid status
Skin carotenoid status (a.u) measured using NuSkin II, resonance Raman spectroscopy
Change in blood carotenoid concentration
Blood carotenoid concentration to be quantified by HPLC

Secondary Outcome Measures

Change in flow mediate dilation
Flow mediate dilation (%)
Change in endothelial function
Endothelial functions are determined by the function of endothelial progenitor cells
Change in the concentration if Endothelin-1 in plasma
Endothelin-1 concentration
Change in the concentration if Nitric Oxide in plasma
Nitric Oxide concentration
Change in body weight
Body weight (kg) measured using body scale
Change in BMI
Weight and height will be combined to report BMI in kg/m^2
Change in blood pressure
Systolic and diastolic blood pressure (mmHg) measured using sphygmomanometer
change in waist circumference
Waist circumference (cm) measured using measuring tape
Change in the concentration of malondialdehyde in plasma
Malondialdehyde concentration
Change in the concentration of 8-iso-prostaglandin F2α in plasma
8-iso-prostaglandin F2α concentration
Change in blood glucose concentration
Blood glucose concentration (mmol/l)
Change in total cholesterol
Total cholesterol (mmol/l)
Change in high-density lipoprotein cholesterol
High-density lipoprotein cholesterol (mmol/l)
Change in low-density lipoprotein cholesterol
Low-density lipoprotein cholesterol (mmol/l)
Change in total triglyceride
Total triglyceride (mmol/l)

Full Information

First Posted
August 30, 2021
Last Updated
March 31, 2023
Sponsor
National University of Singapore
Collaborators
National University Hospital, Singapore, Ministry of Education, Singapore
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1. Study Identification

Unique Protocol Identification Number
NCT05064865
Brief Title
Impact of Regular Consumption of Grapes on Eye Health in Singapore Older Adults
Official Title
Impact of Regular Consumption of Grapes on Eye Health in Singapore Older Adults
Study Type
Interventional

2. Study Status

Record Verification Date
March 2023
Overall Recruitment Status
Active, not recruiting
Study Start Date
January 28, 2022 (Actual)
Primary Completion Date
August 31, 2022 (Actual)
Study Completion Date
October 2023 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
National University of Singapore
Collaborators
National University Hospital, Singapore, Ministry of Education, Singapore

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No

5. Study Description

Brief Summary
Aging epidemics in Singapore are rapidly increasing and Age-related macular degeneration (AMD) prevalence is significantly associated with older age. This study aims to understand the effect of consuming freeze-dried table grape powder on AMD in an older population.
Detailed Description
This will be carried out through a 16-week double-blind, randomized, placebo-controlled trial of parallel study design. Thirty-eight men and women (aged between 60 and 85 years old inclusive) will recruited and assigned to an intervention or placebo group. The intervention group will consume 46 g/day of a freeze-dried table grape and the control group will consume the same amount of a placebo, table grape placebo powder. Measurements of 1) macular pigment optical density (MPOD), a clinical marker for eye health, 2) carotenoids status, 3) markers of oxidative stress, 4) markers of endothelial function, 5) body size and blood pressure, and 6) dietary assessment will be assessed over the 16-week study. This study will consist of 1 screening visit and 5 study visits in 4-week intervals to the Food Science and Technology Department, Occupational Health Clinic and National University Heart Centre.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Eye Health, Age-related Macular Degeneration
Keywords
Eye Health, Age-related Macular Degeneration, carotenoids

7. Study Design

Primary Purpose
Prevention
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
ParticipantInvestigator
Allocation
Randomized
Enrollment
34 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Freeze-dried table grape powder
Arm Type
Experimental
Arm Description
The intervention group will consume 46 g/day of a freeze-dried table grape powder.
Arm Title
Placebo grape powder
Arm Type
Placebo Comparator
Arm Description
The control group will consume the same amount of a placebo with a similar taste to the table grape powder.
Intervention Type
Dietary Supplement
Intervention Name(s)
Freeze-dried table grape powder
Intervention Description
Consumption of 46g/day freeze-dried table grape powder
Intervention Type
Dietary Supplement
Intervention Name(s)
Placebo of the table grape powder
Intervention Description
Consumption of 46g/day placebo version of the freeze-dried table grape powder
Primary Outcome Measure Information:
Title
Change in macular pigment optical density
Description
Macular pigment optical density will be measured using macular pigment scanner
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
Change in skin carotenoid status
Description
Skin carotenoid status (a.u) measured using NuSkin II, resonance Raman spectroscopy
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
Change in blood carotenoid concentration
Description
Blood carotenoid concentration to be quantified by HPLC
Time Frame
Every eight weeks (week 0, week 8, week 16)
Secondary Outcome Measure Information:
Title
Change in flow mediate dilation
Description
Flow mediate dilation (%)
Time Frame
week 0 and week 16
Title
Change in endothelial function
Description
Endothelial functions are determined by the function of endothelial progenitor cells
Time Frame
week 0 and week 16
Title
Change in the concentration if Endothelin-1 in plasma
Description
Endothelin-1 concentration
Time Frame
week 0 and week 16
Title
Change in the concentration if Nitric Oxide in plasma
Description
Nitric Oxide concentration
Time Frame
week 0 and week 16
Title
Change in body weight
Description
Body weight (kg) measured using body scale
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
Change in BMI
Description
Weight and height will be combined to report BMI in kg/m^2
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
Change in blood pressure
Description
Systolic and diastolic blood pressure (mmHg) measured using sphygmomanometer
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
change in waist circumference
Description
Waist circumference (cm) measured using measuring tape
Time Frame
Every four weeks (week 0, week 4, week 8, week 12, week 16)
Title
Change in the concentration of malondialdehyde in plasma
Description
Malondialdehyde concentration
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in the concentration of 8-iso-prostaglandin F2α in plasma
Description
8-iso-prostaglandin F2α concentration
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in blood glucose concentration
Description
Blood glucose concentration (mmol/l)
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in total cholesterol
Description
Total cholesterol (mmol/l)
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in high-density lipoprotein cholesterol
Description
High-density lipoprotein cholesterol (mmol/l)
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in low-density lipoprotein cholesterol
Description
Low-density lipoprotein cholesterol (mmol/l)
Time Frame
Every eight weeks (week 0, week 8, week 16)
Title
Change in total triglyceride
Description
Total triglyceride (mmol/l)
Time Frame
Every eight weeks (week 0, week 8, week 16)

10. Eligibility

Sex
All
Minimum Age & Unit of Time
60 Years
Maximum Age & Unit of Time
85 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Male and female participants, aged between 60 and 85 years old inclusive Able to give informed consent in English Exclusion Criteria: Smokers Allergy to grapes Known eye diseases (macular degeneration, cataracts, retinopathy or glaucoma), blindness in at least one eye or have had eye surgery Abnormal kidney and liver function Taking eye medication and/or dietary supplements for the eyes for the past 3 months Taking supplements containing carotenoids (e.g. Vitamin A, lutein, zeaxanthin) for the past 3 months Currently on type 2 diabetic medication. Currently on anti-hypertensive or cholesterol-lowering; unless this prescription has been ongoing for more than 3 years prior to study participation. Currently on a specialized 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 Poor peripheral venous access based on past experiences with blood draw Participating in another clinical study
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Jung Eun Kim
Organizational Affiliation
National University of Singapore
Official's Role
Principal Investigator
Facility Information:
Facility Name
National University of Singapore
City
Singapore
ZIP/Postal Code
117546
Country
Singapore

12. IPD Sharing Statement

Plan to Share IPD
No
IPD Sharing Plan Description
Electronic copies of the data with identifiable participant information will be key data will be de-identified prior to statistical analysis
Citations:
PubMed Identifier
17101537
Citation
Gehrs KM, Anderson DH, Johnson LV, Hageman GS. Age-related macular degeneration--emerging pathogenetic and therapeutic concepts. Ann Med. 2006;38(7):450-71. doi: 10.1080/07853890600946724.
Results Reference
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Impact of Regular Consumption of Grapes on Eye Health in Singapore Older Adults

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