High iron levels associated with reduced cholesterol

People with high iron levels are less likely to have high cholesterol, according to an international study.

Published in PLOS Medicine, the study found that, in addition to protecting people against anaemia, high iron levels also reduced the likelihood of high cholesterol. However, the authors cautioned that high iron levels can have other detrimental impacts.

The study,  led by Imperial College London, the University of South Australia (UniSA) and University of Ioannina, looked at the role iron plays in 900 diseases, and used genetic and clinical data from approximately 500,000 people in the UK Biobank.

Iron deficiency is well documented, with approximately 1.2 billion people worldwide living with anaemia, leading to serious health problems if left untreated.

What is less known is the impact of excess iron where the body stores too much iron, which can lead to liver disease, heart problems and diabetes in extreme cases.

Around 25% to 65% of differences between individuals in iron levels are due to genetic factors, according to UniSA geneticist Dr Beben Benyamin, joint first author of the paper.

“We used a statistical method, called Mendelian randomisation, that employs genetic data to better estimate the causal effect of iron status on 900 diseases and conditions. Through this, we found a link between excess iron and a reduced risk of high cholesterol,” Dr Benyamin said.

“This could be significant given that raised cholesterol is a major factor in cardiovascular disease and stroke, causing around 2.6 million deaths each year according to the World Health Organization.”

However, it’s a double-edged sword: high iron levels could also lead to a greater risk of bacterial skin infections, such as cellulitis and abscesses.

Previous studies have found that bacteria need iron to survive and flourish, but the Biobank study is the first to use large-scale population data to support the link between iron overload and bacterial skin infections.

Cellulitis affects around 21 million people each year, resulting in more than 17,000 deaths worldwide, making it a global health priority.

Clinical trials have been undertaken to manipulate iron status in anaemic patients but, to date, no trials have targeted iron levels to prevent or treat skin infections or regulate cholesterol. Trial data is essential before iron manipulation is recommended for these disorders.

“In this study we have provided population-based evidence that iron is associated with certain diseases. The next step is to investigate whether direct manipulation of iron levels improves health outcomes through clinical trials,” Dr Benyamin said.

Image credit: ©stock.adobe.com/au/Sergei Ryzhov