Recent research from Cornell University has revealed that individuals of East Asian descent are at a greater risk of developing elevated iron stores compared to those of Northern European descent, potentially leading to an increased susceptibility to chronic diseases such as heart disease, type 2 diabetes, liver disease, and cancer.
This significant finding underscores the necessity of a tailored approach to iron intake to prevent both deficiency and toxicity, which cannot be universally applied across different populations. The research, published in January in the American Journal of Clinical Nutrition, includes three papers co-authored by Professor Kimberly O’Brien from the Division of Nutritional Sciences. These papers highlight the crucial role that genetic factors play in determining nutritional needs and suggest that ongoing genetic research could pave the way for more personalised dietary guidelines for various population subgroups.
Professor O’Brien emphasised the complexity of iron regulation in the human body, noting the evolutionary mechanisms that control iron absorption from our diet. The body must meticulously regulate iron uptake because there is no natural way to expel excess iron once it is absorbed. This meticulous regulation is necessary to prevent iron accumulation in vital organs such as the liver, heart, and pancreas, which can lead to serious health issues.
Iron is consumed in two primary forms: heme iron, which is derived from animal products and absorbed more readily by the body, and non-heme iron, which comes from plant-based foods. The research specifically focused on non-heme iron and its accumulation in different populations, revealing that excess iron stores can heighten the risk of chronic conditions.
Professor O’Brien referred to this issue as precision nutrition, advocating to move away from universal dietary guidelines in favour of more tailored recommendations. For instance, the research suggests that individuals of East Asian heritage may have an intrinsic tendency to accumulate more iron, thus requiring modified dietary advice. The study also highlights a significant gap in nutritional research, which has predominantly focused on subjects of European ancestry, often neglecting underrepresented groups. This oversight could lead to biased nutritional guidelines that do not adequately address the needs of diverse populations.
The research team compared the dietary habits of East Asians and Northern Europeans and found no significant nutritional differences that would account for the disparity in iron accumulation, which appears to be more pronounced in men than in women. This is attributed to the fact that menstruating women lose blood regularly, which helps mitigate iron accumulation. The problem, described by O’Brien as “a silent issue,” often remains undetected in healthy young men but can lead to serious health consequences later in life, typically manifesting after the age of 50.
Professor O’Brien hypothesised that the genetic predisposition among East Asians for higher iron stores could be an evolutionary adaptation to a traditional plant-based, low-iron diet. However, the modern proliferation of fast food options presents new challenges that were not present when these genetic traits evolved. Despite initial studies identifying high body iron stores in Asian populations over two decades ago, there has been limited research exploring the underlying reasons and mechanisms until now. This new research at Cornell University represents a critical step towards understanding and addressing these unique nutritional challenges.
More information: Kimberly O’Brien et al, Characterization of iron status biomarkers and hematological indices among young adults of East Asian or Northern European ancestry: A cross-sectional analysis from the Iron Genes in East Asian and Northern European Adults Study (FeGenes), American Journal of Clinical Nutrition. DOI: 10.1016/j.ajcnut.2024.10.014
Journal information: American Journal of Clinical Nutrition Provided by Cornell University
