Effects of Antioxidants on Human Macular Pigments

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00718653

Enrollment

Registered

2008-07-21

Start date

2004-09-30

Completion date

2007-12-31

Last updated

2009-03-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Eye Health

Keywords

Macular pigment, lutein, green tea extract, antioxidant

Brief summary

Age-related macular degeneration (AMD) is the leading cause of blindness in the United States. Low dietary intake or low blood levels of lutein and zeaxanthin, which are the only pigments found in the macular region of the human retina, has been associated with an increased risk for AMD. We have reported that the dietary supplementation of lutein and zeaxanthin can increase the macular pigments (MP) of the eye. MP effectively absorbs blue light as well as quenches reactive oxygen species (ROS). Green tea polyphenols are also effective scavenger of ROS in vitro. Our goal is to elucidate how to effectively increase MP by physiologic levels of antioxidant supplementation. We hypothesize that lutein and tea polyphenols protect the macula of the eye by increasing MP carotenoids effectively through an antioxidant mechanism.

Interventions

DIETARY_SUPPLEMENTLutein

Lutein (12 mg/d)

DIETARY_SUPPLEMENTLutein plus green tea extract

lutein (12 mg/d) plus green tea extract (200 mg/d)

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

BASIC_SCIENCE

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

50 Years to 70 Years

Healthy volunteers

Yes

Inclusion criteria

* Normal hematologic parameters, normal serum albumin, normal liver function, normal kidney function, absence of fat malabsorption and no drug intake which would interfere with fat absorption, metabolism or blood clotting * non-smokers

Exclusion criteria

* A history of kidney stones, active small bowel disease or resection, atrophic gastritis, hyperlipidemia, insulin-requiring diabetes, alcoholism, pancreatic disease, or bleeding disorders * Exogenous hormone users * weighing greater than 20% above or below the NHANES median standard * subjects with serum lutein/zeaxanthin concentrations that are more than 150 % of median of normal population (as previously reported in NHANES III at same age group) * early age related macular degeneration, cataract, or glaucoma except for those with age appropriate progression of the eye status.

Design outcomes

Primary

Measure	Time frame
macular pigments, Plasma lutein concentrations	Every month - baseline, 1, 2, 3, & 4 months

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026