Try our beta test site
IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more...

Effects of Antioxidants on Human Macular Pigments

This study has been completed.
Information provided by:
National Eye Institute (NEI) Identifier:
First received: July 17, 2008
Last updated: February 27, 2009
Last verified: February 2009

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.

Condition Intervention
Eye Health
Dietary Supplement: Lutein
Dietary Supplement: Lutein plus green tea extract

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: Effects of Antioxidants on Human Macular Pigments

Resource links provided by NLM:

Further study details as provided by National Eye Institute (NEI):

Primary Outcome Measures:
  • macular pigments, Plasma lutein concentrations [ Time Frame: Every month - baseline, 1, 2, 3, & 4 months ]

Enrollment: 40
Study Start Date: September 2004
Study Completion Date: December 2007
Primary Completion Date: December 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Dietary Supplement: Lutein
Lutein (12 mg/d)
Experimental: 2
Lutein plus green tea extract
Dietary Supplement: Lutein plus green tea extract
lutein (12 mg/d) plus green tea extract (200 mg/d)


Ages Eligible for Study:   50 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts 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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00718653

United States, Massachusetts
Jean Mayer USDA-Human Nutrition Research Center on Aging at Tufts University
Boston, Massachusetts, United States, 02111
Sponsors and Collaborators
National Eye Institute (NEI)
Principal Investigator: Kyung-Jin Yeum, Ph.D. Tufts Medical Center
  More Information

Additional Information:
Responsible Party: Kyung-Jin Yeum, Tufts Univeristy Identifier: NCT00718653     History of Changes
Other Study ID Numbers: R03EY015674 ( US NIH Grant/Contract Award Number )
Study First Received: July 17, 2008
Last Updated: February 27, 2009

Keywords provided by National Eye Institute (NEI):
Macular pigment, lutein, green tea extract, antioxidant

Additional relevant MeSH terms:
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs processed this record on April 26, 2017