Omega-3 Fatty Acid Supplementation and Fractional Iron Absorption in Obese South African Women

NCT05220735 | Completed

• 1 other identifier: FeMEGA-3
• Study Type: interventional
• Target: 33
• Locations: 1 country
• Sites: 1

Brief Summary

In South Africa the prevalence of obesity in women of reproductive age is high; these women also have a high risk for iron deficiency (ID). Obesity is associated with low-grade systemic inflammation, which was shown to increase the expression of hepcidin, leading to a reduction in duodenal iron absorption. Thus, alleviating the sub-clinical inflammation associated with obesity could improve iron absorption and status. Supplementation with n-3 long-chain polyunsaturated fatty acids (LCPUFA) has been shown to reduce inflammation in obese individuals. A stable iron isotope study will be performed to investigate the effect of n-3 LCPUFA supplementation on fractional iron absorption in obese South African women.

Conditions

Obesity

Keywords

Fractional iron absorption; Inflammation; Omega-3 fatty acids

Outcome Measures

Primary Outcomes (1)

• Fractional iron absorption (%)

  Fractional iron absorption will be assessed from labeled meals consumed without and with ascorbic acid, before and after intervention with n-3 LCPUFA.

  Change between baseline and 3 months (days 17 and 118)

Secondary Outcomes (12)

• Haemoglobin (g/dL)

  Screening, days 1 and 102

• Ferritin (µg/L )

  Screening, days 1 and 102

• Soluble transferrin receptor (mg/L)

  Screening, days 1 and 102

• Hepcidin concentration

  Screening, days 1 and 102

• C-reactive protein (mg/L)

  Screening, days 1 and 102

Study Arms (1)

Experimental

EXPERIMENTAL

Participants will receive three fish oil capsules daily for 14 weeks, and fractional iron absorption from test meals provided without and with ascorbic acid will be determined at baseline and endpoint.

Dietary Supplement: Omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA)

Interventions

Omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA) DIETARY_SUPPLEMENT

3 three fish oil capsules providing 2.1 g n-3 PUFA; 1.27 g Docosahexanoic acid (DHA) and 0.86 g Eicosapentanoic acid (EPA) capsules. The absorption study test meals will consist of white bread with butter and honey, 6mg of labeled iron as ferrous sulfate and 300 g of distilled water. The meal will be given on two days without and with ascorbic acid. The test meals without ascorbic acid will contain 6 mg 57Fe as ferrous sulfate whereas the meals containing ascorbic acid will contain 6 mg 58Fe as ferrous sulfate.

Experimental

Eligibility Criteria

• Age: 18 Years - 35 Years
• Gender Eligibility Details: Women of reproductive age
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Self-classified women from African descent and of reproductive age (18 - 35 years)
• BMI ≥ 28kg/m2 (indicating obesity)
• Midly- or non-anaemic (Hb ≥11 g/dl)
• Low n-3 LCPUFA status (RBC omega-3 index \< 6%)
• Low grade systemic inflammation (HS-CRP ≥ 2 mg/l but ≤ 20 mg/l)
• Be able to read and understand English

You may not qualify if:

• Treated chronic disease or gastrointestinal disorders
• Regular use of medication (except oral contraceptives, others after approval by the investigator) and women receiving treatment for high blood pressure
• Current consumption of iron or n-3 LCPUFA or ascorbic acid-containing supplements other than the supplements provided (Participants will be asked to discontinue use three weeks prior to enrolment)
• Subject on a weight loss diet or planning to start a weight loss diet during the duration of the study
• Pregnancy or lactation
• Subjects who cannot be expected to comply with the study protocol
• Subjects who are smoking
• Difficulty drawing blood due to poor quality veins
• Individuals that have a fear of needles or suffer from vaso-vagal episodes when exposed to blood
• Subjects with fish allergies
• Participants who plan to start or stop the use of contraceptives in the following 4 months.

Sponsors & Collaborators

• Swiss Federal Institute of Technology: lead
• North-West University, South Africa: collaborator

Study Sites (1)

Centre of Excellence for Nutrition, North-West University

Potchefstroom, South Africa

Location

Related Publications (1)

• Uyoga MA, Baumgartner J, Malan L, Lewies A, Zandberg L, Zeder C, Smuts CM, Herter-Aeberli I. Omega-3 Long-Chain Polyunsaturated Fatty Acid Supplementation Did Not Reduce Inflammation to Improve Iron Absorption in South African Women Living with Overweight or Obesity. J Nutr. 2025 Dec 26:101280. doi: 10.1016/j.tjnut.2025.101280. Online ahead of print.

  PMID: 41456679 DERIVED

MeSH Terms

Conditions

Obesity; Inflammation

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Pathologic Processes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Scientist

Study Record Dates

• First Submitted: January 6, 2022
• First Posted: February 2, 2022
• Study Start: March 7, 2022
• Primary Completion: March 10, 2023
• Study Completion: September 30, 2023
• Last Updated: November 22, 2023

Record last verified: 2023-11

Locations

ZA (1)