NCT01942746

Blueberry Effects on Dark Vision and Glare Recovery

Placebo-controlled Cross-over Studies Examining Blueberries Effects on Dark Vision and Recovery After Photo-bleaching

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 72 (actual)
• Sponsor: Atlantic Food and Horticulture Research Center · Other Government
• Sex: All
• Age: 35 Years – 65 Years
• Healthy volunteers: Accepted

Summary

Clinical evidence for effects of plant anthocyanins on vision, and particularly night vision is controversial. Two clinical trials were conducted to investigate whether blueberry juice consumption affected visual dark adaptation, functional night vision, and recovery after photo-bleaching of the retina. One trial (S2) employed a 3 week intervention and washout period, and two doses of blueberries plus a placebo. The other trial (L1) employed a 12 week intervention plus an 8 week washout and tested one blueberry juice dose against a juice placebo.

Detailed description

Vision Tests: 1. Dark adaptometry, 2. scotopic visual acuity, 3. scotopic contrast sensitivity, 4. rod/cone conversion, 5. recovery after retinal photobleaching

Conditions

• Blindness and Low Vision

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Blueberry Juice S2	Blueberry Juice S2 was commercially prepared single strength blueberry juice composed of a 50:50 blend of Rubel (Vaccinium corymbosum L.) and Tifblue (Vaccinium ashei Reade) cultivars. Colorimetric analysis showed that S2 juice contained 6.04 (SD=0.20) mg anthocyanins (C3G) eq/g dry mass.
DIETARY_SUPPLEMENT	Blueberry Capsules S2	Commercially prepared single strength blueberry juice composed of a 50:50 blend of Rubel (Vaccinium corymbosum L.) and Tifblue (Vaccinium ashei Reade) cultivars was freeze dried then powdered and encapsulated in gelatin capsules. Colorimetric analysis indicated an anthocyanin concentration in the powder of 2.37(SD=0.18) mg C3G eq per capsule.
DIETARY_SUPPLEMENT	Placebo Capsule S2	Placebo Capsule S2 (containing no anthocyanins) were prepared by freeze drying red beets and grinding them to fine powder before encapsulating in gelatine capsules. Red beets do not contain anthocyanins.
DIETARY_SUPPLEMENT	Placebo Juice L1	Placebo juice was prepared from water, sugars, citric acid, sodium citrate, and artificial colors and flavours, then pasteurized. The placebo juice contains no anthocyanins.
DIETARY_SUPPLEMENT	Blueberry Juice L1	Blueberry Juice L1 was commercially prepared single strength blueberry juice composed of a 50:50 blend of Rubel (Vaccinium corymbosum L.) and Tifblue (Vaccinium ashei Reade) cultivars. Colorimetric analysis showed that L1 juice contained 6.83 (SD=0.20) mg cyanidin-3-glucoside equivalents (C3GE)/g dry mass at the start of the study, declining to 5.52 (SD=0.09) mg C3GE/g dry mass after 3 months refrigerated storage.

Timeline

• Start date: 2005-07-01
• Primary completion: 2006-07-01
• Completion: 2006-07-01
• First posted: 2013-09-16
• Last updated: 2013-09-16

Locations

1 site across 1 country: Canada