No ConditionsZIPNCT05182138
Zinc in Potatoes Study
A study testing Unfortified potato plus zinc supplement in people with No Conditions, run by University of Aberdeen at 1 site in United Kingdom.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- No Conditions
- What is being tested?
- Unfortified potato plus zinc supplement
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 36 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 10 Oct 2016to 24 Jun 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Males aged 18 or over
- Postmenopausal females
- Healthy
- BMI 19-35
Who cannot join
- Physical or mental health problems
- Long-term medication
- Smoking
- Alcohol >20 units/week
- Health supplements
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Do Zinc Fortified Potatoes Improve Zinc and Health Status?
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.
Read the detailed description
There is a small but critical window of dietary zinc intake from 1 to 4 mg Zn/day over which the symptoms of long-term zinc deficiency go from acute to chronic in nature. For example, at 1 mg Zn/day intake for several months, most people will develop skin lesions, but at 4 mg Zn/day, skin lesions would be very rare. However, impaired immune response can be detected when consuming zinc up to 6 mg/day over several months. Dietary intakes of <4 mg Zn/day in developed countries is rare but can be common in developing countries.
This study has been carefully designed to test the hypothesis that consumption of zinc biofortified potatoes can rescue the zinc status and health of people who are of low zinc status and consuming diets which are borderline acutely zinc deficient. The protocol for the study includes 2 weeks of zinc deprivation at around 1 mg Zn/day dietary intake (Very Low Zinc Diet) followed by 2 weeks of a borderline acutely/chronically deficient diet of around 4-5 mg Zn/day (Low Zinc Diet). Two weeks on the Very Low Zinc Diet has been carefully and deliberately selected to cause biochemical changes due to zinc deprivation but not signs and symptoms of deficiency such as skin lesions. Less than 2 weeks is insufficient to cause the biochemical effects and more that 2 weeks risks the physical manifestation of deficiency and also non-compliance by volunteers, since the diets may be less palatable than their habitual diet. Thus all volunteers will have low zinc status at the time of starting to eat the Low Zinc Diet, and the effect of eating the biofortified potatoes in addition, which will add an extra 1 mg to the daily zinc intake, should be seen in all the zinc and health status tests that the investigators are proposing. In rat studies in which the investigators did just this kind of intervention, the biofortified potato ameliorated the effect of zinc deficiency on growth, food intake and immune function.
- Conditions
- No Conditions
- Being tested
- Unfortified potato plus placebo, Zinc Biofortified potato plus placebo, Unfortified potato plus zinc supplement
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Unfortified potato plus placeboOther
Volunteers will be given 300g of zinc unfortified cooked potato as well as a placebo every day.
Zinc Biofortified potato plus placeboOther
Volunteers will be given 300g of cooked potato biofortified with zinc and a placebo every day.
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.
| Study group | Role | What they receive |
|---|---|---|
| Unfortified potato plus placebo | Placebo comparator | Volunteers given potato with no fortified zinc and a placebo Receives: Other: Unfortified potato plus placebo |
| Zinc Biofortified potato plus placebo | Active comparator | Volunteers given potato biofortified with zinc and a placebo Receives: Other: Zinc Biofortified potato plus placebo |
| Unfortified potato plus zinc supplement | Active comparator | Volunteers given potato with no fortified zinc and a zinc supplement Receives: Other: Unfortified potato plus zinc supplement |
What is being measured
The primary outcome is the main question the study is designed to answer.
Plasma Zinc status
Plasma zinc levels will be measured using ICP-MS
Measured: 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.
Measured: 4 weeks
Secondary outcomes (2)
Eye Electrophysiology
After overnight dark adaptation using an eye patch, electroretinograms will be recorded following dilation with eye drops G. Tropicamide 1% \& G. phenylephrine 2.5%) using non-invasive corneal electrodes.
Measured: 4 weeks
Thromboelastography (efficiency of blood clotting)
The efficiency of blood clotting within participants will be assessed by collecting whole blood samples into 3.2% sodium citrate tubes and then analysing this for blood clotting parameters using thromboelastography (ROTEM). This analysis generates 4 values representing clot formation which will be assessed and compared between the different interventions: the reaction time (R), the speed of clot formation (K-value), the angle and the maximum amplitude (MA).
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jan 2022
- Study start10 Oct 2016
- Primary completion24 Jun 2019
- Study completion24 Jun 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for No ConditionsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 3 arms in parallel
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Aberdeen
- Sponsor type
- University, hospital or other
- Collaborators
- Fight for Sight
- Responsible party
- Sponsor
- Investigators
- John H Beattie, PhD, Principal investigator, University of Aberdeen
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05182138
- Sponsor's protocol ID
- 02/033/15
- Acronym
- ZIP
- Status last verified
- Jan 2022
- First submitted
- 15 Dec 2021
- Last updated
- 10 Jan 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Jan 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Do Zinc Fortified Potatoes Improve Zinc and Health Status?
- ClinicalTrials.gov ID
- NCT05182138
- Acronym / sponsor ID
- ZIP / 02/033/15
- Conditions
- No Conditions
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- University of AberdeenUniversity, hospital or other
- Collaborators
- Fight for Sight
- Study start
- 10 Oct 2016 (actual)
- Primary completion
- 24 Jun 2019 (actual)
- Study completion
- 24 Jun 2019 (actual)
- First posted
- 10 Jan 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
There is a small but critical window of dietary zinc intake from 1 to 4 mg Zn/day over which the symptoms of long-term zinc deficiency go from acute to chronic in nature. For example, at 1 mg Zn/day intake for several months, most people will develop skin lesions, but at 4 mg Zn/day, skin lesions would be very rare. However, impaired immune response can be detected when consuming zinc up to 6 mg/day over several months. Dietary intakes of <4 mg Zn/day in developed countries is rare but can be common in developing countries.
This study has been carefully designed to test the hypothesis that consumption of zinc biofortified potatoes can rescue the zinc status and health of people who are of low zinc status and consuming diets which are borderline acutely zinc deficient. The protocol for the study includes 2 weeks of zinc deprivation at around 1 mg Zn/day dietary intake (Very Low Zinc Diet) followed by 2 weeks of a borderline acutely/chronically deficient diet of around 4-5 mg Zn/day (Low Zinc Diet). Two weeks on the Very Low Zinc Diet has been carefully and deliberately selected to cause biochemical changes due to zinc deprivation but not signs and symptoms of deficiency such as skin lesions. Less than 2 weeks is insufficient to cause the biochemical effects and more that 2 weeks risks the physical manifestation of deficiency and also non-compliance by volunteers, since the diets may be less palatable than their habitual diet. Thus all volunteers will have low zinc status at the time of starting to eat the Low Zinc Diet, and the effect of eating the biofortified potatoes in addition, which will add an extra 1 mg to the daily zinc intake, should be seen in all the zinc and health status tests that the investigators are proposing. In rat studies in which the investigators did just this kind of intervention, the biofortified potato ameliorated the effect of zinc deficiency on growth, food intake and immune function.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 3
- Model description
- 3 arms in parallel
| Arm | Type | Receives |
|---|---|---|
| Unfortified potato plus placebo | Placebo comparator | Other: Unfortified potato plus placeboVolunteers given potato with no fortified zinc and a placebo |
| Zinc Biofortified potato plus placebo | Active comparator | Other: Zinc Biofortified potato plus placeboVolunteers given potato biofortified with zinc and a placebo |
| Unfortified potato plus zinc supplement | Active comparator | Other: Unfortified potato plus zinc supplementVolunteers given potato with no fortified zinc and a zinc supplement |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Males aged 18 or over
- Postmenopausal females
- Healthy
- BMI 19-35
Key exclusion criteria (5 listed)
- Physical or mental health problems
- Long-term medication
- Smoking
- Alcohol >20 units/week
- Health supplements
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Unfortified potato plus placeboVolunteers will be given 300g of zinc unfortified cooked potato as well as a placebo every day. | Other | Unfortified potato plus placebo |
| Zinc Biofortified potato plus placeboVolunteers will be given 300g of cooked potato biofortified with zinc and a placebo every day. | Other | Zinc Biofortified potato plus placebo |
| Unfortified potato plus zinc supplementVolunteers will be given 300g of zinc unfortified cooked potato and a zinc supplement containing 18mg of zinc, every day. | Other | Unfortified potato plus zinc supplement |
Primary outcome
Plasma Zinc status
Time frame: 4 weeks
Plasma zinc levels will be measured using ICP-MS
Zinc status
Time frame: 4 weeks
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.
2 secondary outcomes
Eye Electrophysiology
Time frame: 4 weeks
Thromboelastography (efficiency of blood clotting)
Time frame: 4 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jan 2022.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
John H Beattie, PhD principal investigator
University of Aberdeen
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Unfortified potato plus zinc supplement in people with No Conditions, run by University of Aberdeen at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 Jan 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Plasma Zinc status (time frame: 4 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jan 2022.