NCT05182138

Brief Summary

Zinc is important in biology and allows the proper function of proteins in living organisms. Severe zinc deficiency in animals and humans over long periods of time can therefore cause adverse effects. In the UK, the zinc status of most people is adequate, but about 20% of the population, especially adolescents in deprived communities and vegetarians/vegans, are likely marginally zinc deficient. Because potatoes are a favoured food in adolescents and vegetarians/vegans, the investigators have improved the zinc content of Saxon potatoes by biofortification, which involves spraying potato plant leaves with zinc salts. The potato zinc concentration is about three times the level in unfortified potatoes of the same variety. This level of zinc can boost the zinc intake of people who are marginally zinc deficient so that they become zinc adequate. Indeed, in rat studies, the investigators have shown that addition of some zinc-biofortified potato to a low zinc diet improves the zinc and health status of the animals. In the present study, the investigators propose to investigate whether the potato biofortification can improve the zinc and health status of volunteers. Because most of the volunteers (healthy adult men and women after the menopause) might have normal or variable zinc status at recruitment, it might not be possible to see the benefits of the potato diets and therefore, the investigators shall reduce the zinc intake of all 45 participants to 1 mg Zn/d for a period of two weeks prior to feeding 15 randomly selected individuals the biofortified potato diets (4 mg Zn/d) for two weeks. Zinc and health status will be measured by blood tests before and after zinc depletion and after feeding the potato diets. Results will be compared with data from 15 volunteers eating unfortified potato diets with a daily placebo and 15 volunteers consuming the unfortified potato diets with a zinc supplement (18 mg/d) as a positive control.

Trial Health

87
On Track

Trial Health Score

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

Enrollment
36

participants targeted

Target at P25-P50 for not_applicable

Timeline
Completed

Started Oct 2016

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

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

Trial Relationships

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Study Timeline

Key milestones and dates

Study Start

First participant enrolled

October 10, 2016

Completed
2.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 24, 2019

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 24, 2019

Completed
2.5 years until next milestone

First Submitted

Initial submission to the registry

December 15, 2021

Completed
26 days until next milestone

First Posted

Study publicly available on registry

January 10, 2022

Completed
Last Updated

January 10, 2022

Status Verified

January 1, 2022

Enrollment Period

2.7 years

First QC Date

December 15, 2021

Last Update Submit

January 6, 2022

Conditions

No Conditions

Outcome Measures

Primary Outcomes (2)

  • Plasma Zinc status

    Plasma zinc levels will be measured using ICP-MS

    4 weeks

  • Zinc status

    The Exchangeable Zinc Pool size (EZP) will be assessed by the analysis of the Zn stable isotopes excreted in the urine by ICP-MS/MS.

    4 weeks

Secondary Outcomes (2)

  • Eye Electrophysiology

    4 weeks

  • Thromboelastography (efficiency of blood clotting)

    4 weeks

Study Arms (3)

Unfortified potato plus placebo

PLACEBO COMPARATOR

Volunteers given potato with no fortified zinc and a placebo

Other: Unfortified potato plus placebo

Zinc Biofortified potato plus placebo

ACTIVE COMPARATOR

Volunteers given potato biofortified with zinc and a placebo

Other: Zinc Biofortified potato plus placebo

Unfortified potato plus zinc supplement

ACTIVE COMPARATOR

Volunteers given potato with no fortified zinc and a zinc supplement

Other: Unfortified potato plus zinc supplement

Interventions

Unfortified potato plus placeboOTHER

Volunteers will be given 300g of zinc unfortified cooked potato as well as a placebo every day.

Unfortified potato plus placebo
Zinc Biofortified potato plus placeboOTHER

Volunteers will be given 300g of cooked potato biofortified with zinc and a placebo every day.

Zinc Biofortified potato plus placebo
Unfortified potato plus zinc supplementOTHER

Volunteers will be given 300g of zinc unfortified cooked potato and a zinc supplement containing 18mg of zinc, every day.

Unfortified potato plus zinc supplement

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Males aged 18 or over
  • Postmenopausal females
  • Healthy
  • BMI 19-35

You may not qualify if:

  • Physical or mental health problems
  • Long-term medication
  • Smoking
  • Alcohol \>20 units/week
  • Health supplements

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Aberdeen

Aberdeen, AB25 2ZD, United Kingdom

Location

Study Officials

  • John H Beattie, PhD

    University of Aberdeen

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR
Masking Details
Computer-based randomisation system
Purpose
TREATMENT
Intervention Model
PARALLEL
Model Details: 3 arms in parallel
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 15, 2021

First Posted

January 10, 2022

Study Start

October 10, 2016

Primary Completion

June 24, 2019

Study Completion

June 24, 2019

Last Updated

January 10, 2022

Record last verified: 2022-01

Data Sharing

IPD Sharing
Will not share

Locations

GB(1)