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Completed

NCT Number: NCT02550483

Novel Metabolites of Beta-Carotene and Lycopene

The study (n = 36) will be a parallel design and will be 6 weeks in duration. Participants will start with a 2-week free-living wash-in period where they will be asked to avoid certain carotenoid-rich foods, followed by 4 weeks of a completely controlled diet. In addition to the controlled diet, participants will consume one of three beverages (300 mL/day; n = 12/group): placebo beverage (control), high beta-carotene tomato juice, and high-lycopene tomato juice. Blood, urine and feces will be collected throughout the study.

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Key information

Conditions

Healthy

Age range

21 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

USDA Beltsville Human Nutrition Research Center

Beltsville, Maryland, 20705, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Exclusion criteria

  • Age less than 21 or greater than 75 years
  • Glucose > 126 mg/dl
  • Triglycerides > 300 mg/dl
  • Known allergy or intolerance to tomatoes or tomato products
  • Pregnant, lactating, or intend to become pregnant during the study period
  • History of bariatric surgery or nutrient malabsorption disease (such as celiac disease) or other metabolic disorders requiring special diet recommendations
  • Smoker or use of tobacco products
  • Presently have cancer
  • Use of certain medications (prescription or over-the-counter) that may interfere with the study objectives
  • Type 2 diabetes
  • Use of blood-thinning medications such as Coumadin (warfarin), Dicumarol, or Miradon (anisindione)
  • Unable or unwilling to give informed consent or communicate with study staff
  • Self-report of alcohol or substance abuse within the past 12 months and/or current acute treatment or rehabilitation program for these problems (long-term participation in Alcoholics Anonymous is not an exclusion)
  • Other medical, psychiatric, or behavioral factors that in the judgment of the Principal Investigator may interfere with study participation or the ability to follow the intervention protocol

Treatment and study plan

Base diet + high beta-carotene tomato juice

Other

Participants will receive high beta-carotene tomato juice daily in addition to the base diet. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. The base diet will be low in betacarotene and lycopene (no carrots, sweet potato, tomatoes, and dark greens). During the controlled diet period, participants will be instructed to eat all foods and only foods provided to them, with the exception of water, coffee, tea, and diet soda.

Base diet + high lycopene tomato juice

Other

Participants will receive high lycopene tomato juice daily in addition to the base diet. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. The base diet will be low in betacarotene and lycopene (no carrots, sweet potato, tomatoes, and dark greens). During the controlled diet period, participants will be instructed to eat all foods and only foods provided to them, with the exception of water, coffee, tea, and diet soda.

Base diet + placebo beverage

Other

Participants will receive a placebo beverage daily in addition to the base diet. Meals will be prepared using traditional American foods with a macronutrient composition representative of a typical American diet. The base diet will be low in betacarotene and lycopene (no carrots, sweet potato, tomatoes, and dark greens). During the controlled diet period, participants will be instructed to eat all foods and only foods provided to them, with the exception of water, coffee, tea, and diet soda.

Primary outcomes

  1. Change in apocarotenoid concentrations will be measured in blood

    Time frame: Baseline, 2 weeks, 4 weeks

    Apocarotenoid concentrations will be measured in blood (baseline, after washout; 2 wks; 4 wks).

  2. Change in carotenoid concentrations will be measured in blood

    Time frame: Baseline, 2 weeks, 4 weeks

    Carotenoid concentrations will be measured in blood (baseline, after washout; 2 wks, 4 wks).

Secondary outcomes

  1. Change in global gene expression

    Time frame: Baseline, 4 weeks

    Amounts of messenger RNA will be measured in blood samples to determine if the consumption of carotenoid-rich foods will affect gene expression of pathways related to cancer risk.

  2. Change in proportion of phyla of colonic microbiota

    Time frame: Baseline, 4 weeks

    Ribosomal RNA will be measured to determine relative amounts of different bacterial phyla present in the colon after consumption of the juice products differing in carotenoid concentration.

  3. Identification of unknown urinary carotenoid metabolites

    Time frame: Baseline, 2 weeks, 4 weeks

    Identify previously unknown carotenoid metabolites in urine.

Sponsors and collaborators

Lead sponsor

USDA Beltsville Human Nutrition Research Center

Fed

Registry information

Important dates

Study start
2015
Primary completion
2015
Study completion
2015
First posted
Sep 15, 2015
Registry last updated
Apr 26, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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