Impact of Grape Powder Consumption on Eye Health and Glycemic Status in Singapore Older Adults

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.

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.

Inclusion Criteria:

1. Male and female participants, aged between 60 and 85 years old inclusive
2. English-literate and able to give informed consent in English

Exclusion Criteria:

1. Smokers
2. Allergy to grapes or food dyes/additives, or had serious food allergies in the past
3. Known eye diseases (macular degeneration, cataracts, retinopathy or glaucoma), blindness in at least one eye or have had eye surgery
4. Unable to view bright lights or flashing lights
5. Has Type 1 or 2 diabetes, uremia, cardiovascular disease, abnormal kidney and liver function
6. Taking eye medication and/or dietary supplements for the eyes for the past 3 month
7. Taking supplements containing carotenoids (e.g. Vitamin A, lutein, zeaxanthin) for past 3 months
8. Currently on a specialised diet (e.g. vegetarian, vegan, weight loss diet, low fat diet
9. 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
10. Significant change in weight (≥ 3 kg body weight) in the past 3 months
11. Significant exercise pattern over the past 3 months defined as high-intensity exercise of more than 3 hours per week
12. Currently on anti-hypertensive, cholesterol-lowering or psychoactive drugs
13. Scored ≤ 7 on the abbreviated mental test
14. Poor peripheral venous access based on past experiences with blood draw
15. Participating in another clinical study