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Zinc and Iron Absorption From Common Beans in Young Adult Women

Not Applicable
Recruiting
Conditions
Iron Absorption
Zinc Absorption
Interventions
Other: LPA 586
Other: SER 118
Other: LMP 1001
Other: KAT B1
Registration Number
NCT06327529
Lead Sponsor
University of California, Davis
Brief Summary

Fifteen female study participants will be enrolled in a randomized crossover study to measure fractional and total zinc and iron absorption from four common bean (Phaseolus vulgaris) varieties with varying phytate and polyphenolic contents. Phytate, the storage form of phosphorus in plants, and polyphenols, which contribute to the varied colors of common beans, are natural components of the beans and can reduce zinc and iron bioavailability from these foods.

Detailed Description

Each participant will attend a total of 10 study visits. The first visit will be a screening visit to determine eligibility, and will include the administration of health history and food frequency questionnaires, and a urine pregnancy test. Participant will also be given a ASA24 24-hour dietary recall at visit 1 to return at visit 2. All subsequent visits (2 through 10) will begin with a blood sample (15 mL, or 1 tablespoon, after a 12 hour overnight fast).

Visit 2 will establish the baseline distribution of naturally occurring zinc and iron isotopes in the blood, and will include the administration of water enriched in zinc of a specific naturally-occurring isotopic mass (zinc-68, 4 mg).

Visits 2-5 will be on consecutive days, while Visit 6 will be 14 days following Visit 5. Visits 3 and 4 will include breakfast, lunch, and dinner, each containing a small serving of beans that are enriched in specific isotopic masses of iron and zinc (2 mg each of zinc-67 and iron-57, or 1 mg each of zinc-70 and iron-58). Visits 5 and 6 are for blood sampling, to measure the zinc in blood plasma (Visit 5) and the iron that has reached a 14-day equilibrium in red blood cells (Visit 6). Participants will also be given a ASA24 24-hour dietary recall at visit 6 to return at visit 7.

Visits 6-9 will be on consecutive days, starting 28 days (the approximate length of one menstrual cycle) after Visit 3, while Visit 10 will be 14 days following Visit 9. The 28-day timing is needed to minimize the potential influence of natural variation in circulating hormones, on zinc metabolism. A second urine pregnancy test will be administered on Visit 10, to detect any pregnancies that would have occurred at the time of the study meals 2 weeks prior or earlier. Participants will also be given a ASA24 dietary recall at visit 9 to return at visit 10.

Recruitment & Eligibility

Status
RECRUITING
Sex
Female
Target Recruitment
15
Inclusion Criteria
  • Healthy eumenorrheic (regular monthly menstrual cycles of 25-30-days in length)
  • BMI 18.5 - 30 kg/m2
  • Regular consumer of beans, i.e. ≥ 4 servings per month
  • Usual iron intake estimated by Food Frequency Questionnaire to be less than the Recommended Daily Allowance (RDA) of 18 mg/d (8)
  • Subject is willing and able to comply with the study protocols.
  • Subject is willing to participate in all study procedures.
Exclusion Criteria
  • Dislike or allergy to beans
  • Self-reported current or recent pregnancy (within the past 12 months)
  • Self-reported recent termination of pregnancy (3 months if abortion in 1st or 2nd trimester, or 12 months if in 3rd trimester)
  • Self-reported plans to become pregnant during the study period
  • Self-reported cancer
  • Self-reported surgery without the past 12 months
  • Currently taking prescription drugs, other than for contraception, or any nutritional supplements
  • Any daily iron supplementation within the past 12 months.
  • Currently breastfeeding
  • Any medical conditions affecting iron or zinc metabolism (such as hemochromatosis or sickle cell disease)

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Bean Variety 3LPA 586Enriched with Zinc-67, Iron-57
Bean Variety 1SER 118Enriched with Zinc-67, Iron-57
Bean Variety 2LMP 1001Enriched with Zinc-70, Iron-58
Bean Variety 4KAT B1Enriched with Zinc-70, Iron-58
Primary Outcome Measures
NameTimeMethod
Fractional Zinc absorption24 hours after first intake

amount of zinc absorbed and circulating in blood

Fractional Iron absorption24 hours after first intake

amount of iron absorbed and circulating in the blood

Secondary Outcome Measures
NameTimeMethod
Total Zinc absorption24 hours after first intake

total amount of zinc absorbed from meals

Total Iron absorption24 hours after first intake

total amount of iron absorbed from meals

Trial Locations

Locations (1)

Department of Nutrition

🇺🇸

Davis, California, United States

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