#466: Iron Absorption from Foods & Supplements – Prof. Paul Sharp

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Introduction

Iron deficiency is a prevalent issue. Worldwide, it is the leading nutritional deficiency. And although there is lower prevalence in high-income countries, a significant number of people are still affected.

Iron deficiency may be a result of too little iron coming in (i.e., via diet choices or low absorption), or from excess losses (e.g., commonly from blood losses). Understanding how these can impact iron status is crucial for both accurate diagnosis and treatment.

In relation to dietary iron, the source of iron is a common talking point, as there are two forms of iron that we can consume. Heme iron is found in meat, fish, and poultry, while non-heme iron is found in plant foods. It is known that heme iron is more readily absorbed than non-heme iron. However, there is much more to this story that makes things complicated.

To discuss some of the nuances of iron bioavailability, absorption, and metabolism, leading expert in the area Professor Paul Sharp of King’s College London is on the podcast. Prof. Sharp discusses crucial aspects of dietary iron sources, bioavailability, supplementation, and impacts in the body.

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Guest Information

Prof. Paul Sharp, PhD

Paul Sharp is Professor of Nutritional Sciences and Head of Department of Nutrition & Dietetics at King’s College London. He has worked on the mechanisms regulating nutrient absorption and metabolism for over 25 years.

He has expertise in the fundamental mechanisms controlling iron metabolism at the cellular level and how these processes are regulated at nutrigenomic and epigenetic levels.

His current work addresses the impact of biofortification, agronomic practices, and food processing methods on the content and localisation of micronutrients in cereals and vegetables, and the bioaccessibility and bioavailability of vitamins and minerals from plant-based foods.

His work has been funded by awards from UKRI, UK charities and industry and his team are currently partners on several international GCRF collaborations on mineral bioavailability.

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Overview

• Dietary soures of iron and factors affecting absorption
• Heme vs. non-heme iron: Misunderstood concepts
• Inhibitors and enhancers
• Discrepancy between whole diet interventions and the results of single meal studies.
• Impact of clinical disorders and genetics on absorption
• Iron supplements: Forms, dosing, and non-response
• Roles of iron and aspects of metabolism

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Related Resources

• Previous episode on Iron: Episode 465 with Dr. Austin Baraki
• Twitter: @SharpProfessor
• KCL Pure: Prof. Sharp’s publications
• BNF webinar: Processing the Nutribabble – Is Natural Always Best?
• Futher reading:
  • Kondaiah et al., 2019 – Iron and Zinc Homeostasis and Interactions: Does Enteric Zinc Excretion Cross-Talk with Intestinal Iron Absorption?
  • Aslam et al., 2018 – Enhancing mineral bioavailability from cereals: Current strategies and future perspectives
  • Christides et al., 2015 – Iron bioavailability from commercially available iron supplements
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Detailed Study Notes

Detailed Study Notes

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Transcript

Episode Transcript

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