Macroalgae Consumption - a Pilot Study

In this study, the aim is to investigate the food safety of macroalgae. There will be an analysis of macroalgae products for the concentration of cadmium, inorganic arsenic, and iodine in macroalgae, as well as measure the status of these elements in consumers. An investigation of the thyroid function of macroalgae consumers and the use of metabolomics to explore which biological changes occur when consuming seaweed and kelp and when the consumer excludes macroalgae from their diet will be performed.

Study Overview

• Status: Completed
• Conditions: Iodine Toxicity
• Intervention / Treatment: Other: Habitual macroalgae consumption; Other: No macroalgae consumption

Detailed Description

A group of consumers of macroalgae will be recruited to investigate their macroalgae intake and iodine, cadmium, and inorganic arsenic status and thyroid function. Iodine, cadmium, and inorganic arsenic have been selected since these elements have been described as relatively high in a previously published report from Norway. The goal is to recruit consumers of brown algae - especially kelp, and certain types of red algae, as these were the species with the highest content of iodine, cadmium, and arsenic, described in a previous publication. The participants will be asked to abstain from macroalgae for 6 weeks and again examine iodine status, cadmium and arsenic exposure, and thyroid function after the cessation period. A withdrawal period of 6 weeks has been chosen on the basis that it is calculated 6-8 weeks after Levaxin treatment for hypothyroidism before a new equilibrium can be expected and the effect of treatment on TSH can be assessed.

This study will provide new insight into the status of iodine, cadmium, and inorganic arsenic that macroalgae consumers have in urine and thyroid function after regular macroalgae consumption and after cessation of macroalgae intake. In addition, the study will provide descriptive data on macroalgae consumption, how it is eaten, how often, and how much. This can provide critical knowledge to the national and European authorities for food safety and public health advisers to evaluate the food safety of macroalgae.

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Norway
  • Bergen, Norway, 5021
    • University of Bergen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• adults
• weekly consumer of macroalgae

Exclusion Criteria:

• pregnant
• known disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Usual macroalgae consumption; Crossover design with habitual macroalgae consumption at baseline	Other: Habitual macroalgae consumption; The participant have a habitual macroalgae consumption at baseline.; Other: No macroalgae consumption; The participants exclude any macroalgae products from their diet
Experimental: Cessation of macroalgae consumption; Cessation of macroalgae consumption as an experimental intervention.	Other: Habitual macroalgae consumption; The participant have a habitual macroalgae consumption at baseline.; Other: No macroalgae consumption; The participants exclude any macroalgae products from their diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Consumption of macroalgae products	Assess the dietary consumption of macroalgae in consumers in the Bergen and Oslo area by 24hr recall and food frequency questionnaire	Through study completion, on average 6 weeks
Levels of iodine, cadmium and inorganic arsenic in macroalgae products	Analyse the levels of iodine, cadmium and inorganic arsenic in macroalgae products used by the participants	Through study completion, on average 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Levels of iodine	Analyse the levels of iodine in urine after intervention/usual macroalgae consumption	6 weeks
Levels of cadmium in urine	Analyse the levels of cadmium urine after intervention/usual macroalgae consumption	6 weeks
Levels of inorganic arsenic in urine	Analyse the levels of inorganic arsenic in urine after intervention/usual macroalgae consumption	6 weeks
Levels of creatinine in urine	Analyse the of creatinine in urine after intervention/usual macroalgae consumption	6 weeks
Thyroid function measure by thyroid-stimulating hormon	Measurement of thyroid-stimulating hormon (TSH) in serum after intervention/usual macroalgae consumption	6 weeks
Thyroid function measure by ree-triiodinetyronin	Measurement of free-triiodinetyronin (fT3) in serum after intervention/usual macroalgae consumption	6 weeks
Thyroid function measure by free thyroxine	Measurement of free thyroxine (fT4) in serum after intervention/usual macroalgae consumption	6 weeks
Thyroid function measure by Thyroid peroxidase antibody	Measurement of Thyroid peroxidase antibody (TPOAb) in serum after intervention/usual macroalgae consumption	6 weeks
Thyroid function measured by thyroglobulin	Measurement of thyroglobulin (Tg) in serum after intervention/usual macroalgae consumption	6 weeks
Thyroid function	Measurement of thyroid-stimulating hormon (TSH), free-triiodinetyronin (fT3), free thyroxine (fT4), Thyroid peroxidase antibody (TPOAb), thyroglobulin (Tg) in serum after intervention/usual macroalgae consumption	6 weeks
Metabolic changes	Measurement of metabolic changes by non-targeted metabolomics after intervention/usual macroalage consumption	6 weeks

Collaborators and Investigators

• Sponsor: University of Bergen
• Collaborators: Institute of Marine Research
• Investigators: Principal Investigator: Inger Aakre, PhD, Institute of Marine Research

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2022
• Primary Completion (Actual): December 15, 2022
• Study Completion (Actual): January 1, 2023

Study Registration Dates

• First Submitted: March 6, 2023
• First Submitted That Met QC Criteria: July 3, 2023
• First Posted (Actual): July 11, 2023

Study Record Updates

• Last Update Posted (Actual): July 11, 2023
• Last Update Submitted That Met QC Criteria: July 3, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: iodine; consumption; macroalgae
• Other Study ID Numbers: 332865

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No