NCT05283941

Brief Summary

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss as people age. Studies have shown that lutein and zeaxanthin, nutrients found in green leafy vegetables and egg yolks, can help protect against AMD in older adults. These nutrients form a pigment in the retina (macular pigment) that can help protect the retina from light damage. Pistachios are rich sources of both lutein and zeaxanthin; thus, dietary intake of pistachios could serve as a beneficial food source for eye health.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
40

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Jun 2022

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

February 22, 2022

Completed
23 days until next milestone

First Posted

Study publicly available on registry

March 17, 2022

Completed
3 months until next milestone

Study Start

First participant enrolled

June 10, 2022

Completed
1.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 30, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

November 30, 2023

Completed
Last Updated

March 9, 2023

Status Verified

March 1, 2023

Enrollment Period

1.5 years

First QC Date

February 22, 2022

Last Update Submit

March 7, 2023

Conditions

Macular DegenerationRetinal DegenerationRetinal DiseasesEye Diseases

Keywords

age related macular degenerationluteinzeaxanthinpistachiosmacular pigmentAMD

Outcome Measures

Primary Outcomes (1)

  • Change from baseline Macular Pigment (MP) Density over 12 weeks

    A non-invasive psychophysical technique, known as heterochromatic flicker photometry (HFP), will be used to measure MP density of the retina.

    Measured at baseline, 6 weeks and 12 weeks.

Secondary Outcomes (1)

  • Serum concentrations of lutein and zeaxanthin (dietary carotenoids)

    Measured at baseline and 12 weeks.

Study Arms (2)

Pistachio Group

EXPERIMENTAL

The pistachio group will receive pistachio nuts in 2-ounce packs. This group will consume one pack every day over the course of the 12-week study.

Dietary Supplement: Pistachio Group

Control (Usual Diet) Group

NO INTERVENTION

The control group will not receive pistachio nuts. They will be asked to make no changes and continue to eat their regular diet.

Interventions

Pistachio GroupDIETARY_SUPPLEMENT

Consumption of 2-ounce packs of pistachio nuts, daily, for 12 weeks.

Pistachio Group

Eligibility Criteria

Age40 Years - 70 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Adult men and women, aged 40 - 70 years
  • Body Mass Index (BMI): 20.0 - 36.9 kg/m2
  • Low macular pigment density at baseline (\<0.5 OD)
  • Low lutein and zeaxanthin intake at baseline (\<2 mg/d)

You may not qualify if:

  • Inability to perform the heteroflicker photometry procedures with or without corrective lenses (i.e. glasses or contact lenses) during in-house screening.
  • History of (self-reported):
  • Fat malabsorption
  • Use of drugs that interfere with fat absorption or metabolism
  • Tree nut allergy
  • Eye disease, including macular degeneration and cataracts
  • Small bowel disease or resection
  • Atrophic gastritis
  • Hyperlipidemia
  • Insulin-requiring diabetes
  • \> 14 alcoholic drinks per week
  • Pancreatic disease
  • Bleeding disorders
  • Pregnancy (or hoping to become pregnant during participation in the study)
  • Carotenoid or fatty acid dietary supplements within 2 months of the study
  • +2 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Clinical and Translational Research Center (CTRC) - Tufts

Boston, Massachusetts, 02111, United States

RECRUITING

Related Publications (1)

  • Scott TM, Ogunbodede O, McKay DL, Johnson EJ. Pistachio Consumption Increases Macular Pigment Optical Density in Healthy Adults: A Randomized Controlled Trial. J Nutr. 2025 Jan;155(1):168-174. doi: 10.1016/j.tjnut.2024.10.022. Epub 2024 Oct 18.

    PMID: 39426460DERIVED

MeSH Terms

Conditions

Macular DegenerationRetinal DegenerationRetinal DiseasesEye Diseases

Condition Hierarchy (Ancestors)

Eye Diseases, Hereditary

Study Officials

  • Tammy Scott

    Tufts University

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Tammy Scott, PhD

CONTACT

617-962-1496tammy.scott@tufts.edu

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 22, 2022

First Posted

March 17, 2022

Study Start

June 10, 2022

Primary Completion

November 30, 2023

Study Completion

November 30, 2023

Last Updated

March 9, 2023

Record last verified: 2023-03

Data Sharing

IPD Sharing
Will not share

Locations

US(1)