Age-related Macular Degeneration, Eye Health
Conditions
Keywords
Eye Health, Age-related Macular Degeneration, carotenoids
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.
Interventions
DIETARY_SUPPLEMENTFreeze-dried table grape powder
Consumption of 46g/day freeze-dried table grape powder
DIETARY_SUPPLEMENTPlacebo of the table grape powder
Consumption of 46g/day placebo version of the freeze-dried table grape powder
Sponsors
National University Hospital, Singapore
Ministry of Education, Singapore
National University of Singapore
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
60 Years to 85 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in macular pigment optical density | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Macular pigment optical density will be measured using macular pigment scanner |
| Change in skin carotenoid status | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Skin carotenoid status (a.u) measured using NuSkin II, resonance Raman spectroscopy |
| Change in blood carotenoid concentration | Every eight weeks (week 0, week 8, week 16) | Blood carotenoid concentration to be quantified by HPLC |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in the concentration if Nitric Oxide in plasma | week 0 and week 16 | Nitric Oxide concentration |
| Change in body weight | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Body weight (kg) measured using body scale |
| Change in BMI | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Weight and height will be combined to report BMI in kg/m\^2 |
| Change in blood pressure | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Systolic and diastolic blood pressure (mmHg) measured using sphygmomanometer |
| change in waist circumference | Every four weeks (week 0, week 4, week 8, week 12, week 16) | Waist circumference (cm) measured using measuring tape |
| Change in the concentration of malondialdehyde in plasma | Every eight weeks (week 0, week 8, week 16) | Malondialdehyde concentration |
| Change in flow mediate dilation | week 0 and week 16 | Flow mediate dilation (%) |
| Change in blood glucose concentration | Every eight weeks (week 0, week 8, week 16) | Blood glucose concentration (mmol/l) |
| Change in total cholesterol | Every eight weeks (week 0, week 8, week 16) | Total cholesterol (mmol/l) |
| Change in high-density lipoprotein cholesterol | Every eight weeks (week 0, week 8, week 16) | High-density lipoprotein cholesterol (mmol/l) |
| Change in low-density lipoprotein cholesterol | Every eight weeks (week 0, week 8, week 16) | Low-density lipoprotein cholesterol (mmol/l) |
| Change in total triglyceride | Every eight weeks (week 0, week 8, week 16) | Total triglyceride (mmol/l) |
| Change in the concentration of 8-iso-prostaglandin F2α in plasma | Every eight weeks (week 0, week 8, week 16) | 8-iso-prostaglandin F2α concentration |
| Change in endothelial function | week 0 and week 16 | Endothelial functions are determined by the function of endothelial progenitor cells |
| Change in the concentration if Endothelin-1 in plasma | week 0 and week 16 | Endothelin-1 concentration |
Countries
Singapore
Outcome results
None listed