Micronutrient Bioavailability From Wheat

King's College London

Status: Unknown

Conditions: Healthy

Treatments: Other: Bread product (standard milled); Other: Bread Product (micro-milled); Other: Bread product (micro-milled aleurone); Other: Bread Product (standard aleurone)

Study type: Interventional

Funder types: Other

Identifiers

NCT05536947

HR-18/19-5718

Details and patient eligibility

About

The purpose of this study is to determine if physical disruption of wheat aleurone cell walls (micro-milling) increases micronutrient availability.

Full description

This research project is a short-term dietary intervention study to investigate the bio-availability of iron and zinc from wheat. Approximately 50% of iron and 30% of zinc in the United Kingdom diet is provided by cereals and cereal products (e.g. bread and breakfast cereals). The localisation of both iron and zinc metals in wheat is largely confined to the aleurone layer, a single layer of cells located between the centre (endosperm) and outer layers (testa and pericarp). The aleurone layer is removed during the production of white flour. For this reason, since 1953 it has been mandatory to add iron to flours at the mill to restore iron to levels present in wholegrain flour (The Bread and Flour Regulations, 1998).

The investigators have shown that aleurone cells are resistant to physical disruption and digestion as they pass along the gastrointestinal tract and are excreted intact in faeces. The investigators believe that disruption of wheat aleurone cell walls prior to food manufacturing would therefore increase iron and zinc availability. Using wholegrain flour and purified wheat aleurone flour the investigators have shown that micro-milling, a process which reduces particle size of flour from approximately 100μm to 10μm, ruptures the aleurone cell walls, and increases iron availability, i.e. the amount absorbed by intestinal cells, compared with flour produced using standard milling techniques (which does not break down the aleurone layer).

Based on these initial findings, the current study therefore has 2 main aims:

(i) to determine whether physical disruption of the aleurone (by micro-milling) in wholegrain flour increases iron and zinc availability from wholegrain bread.

(ii) to determine whether addition of micro-milled aleurone flour to white flour increases iron availability from white bread.

Enrollment: 25 estimated patients

Sex: Female

Ages: 19 to 49 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Healthy pre-menopausal women
• Serum ferritin below 30 μg/L
• Plasma zinc below 13.8 μmol/L.

Exclusion criteria

• Allergic to gluten or wheat
• Pregnant
• Post-menopausal women
• History of alcohol or substance abuse
• History of Cardiovascular Disease, diabetes, cancer, kidney, liver or intestinal disease, gastrointestinal disorder or use of drugs likely to alter gastrointestinal function.
• Donated blood recently (within 3 months prior to screening visit)
• Volunteers planning to take any mineral or vitamin supplements during the course of the study.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Triple Blind

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25 participants in 4 patient groups

Standard-milled Wholegrain

Active Comparator group

Description:

Bread rolls prepared using standard-milled Wholegrain (75 g per bread roll, containing stable isotopes of Fe and Zn), with butter and strawberry jam.

Treatment:

Other: Bread product (standard milled)

Micro-milled Wholegrain

Experimental group

Description:

Bread rolls prepared using Micro-milled Wholegrain (75 g per bread roll, containing stable isotopes of Fe and Zn), with butter and strawberry jam.

Treatment:

Other: Bread Product (micro-milled)

White flour fortified with standard milled Aleurone

Active Comparator group

Description:

Bread rolls prepared using a white flour and standard-milled aleurone mix (75 g per bread roll, containing stable isotope of Fe), with butter and strawberry jam.

Treatment:

Other: Bread Product (standard aleurone)

White flour fortified with micro-milled Aleurone

Experimental group

Description:

Bread rolls prepared using a white flour and micro-milled aleurone mix (75 g per bread roll, containing stable isotope of Fe), with butter and strawberry jam.

Treatment:

Other: Bread product (micro-milled aleurone)