Plant-Based Diet and Risk of Iron-deficiency Anemia. A Review of the Current Evidence and Implications for Preventive Strategies

Abstract

Purpose of review: This review provides a comprehensive overview of iron metabolism, emphasizing the influence of dietary patterns-particularly vegetarian and vegan diets-on iron status and associated health outcomes.

Recent findings: Concerns regarding iron deficiency anemia in individuals following plant-based diets necessitate a deeper comprehension of the factors affecting iron bioavailability and absorption. Non-heme iron, which is more abundant in plant-based sources, poses challenges about its lower bioavailability and this could contribute to an increased risk of anemia in these populations. However, recent studies challenge this assumption, revealing a more complex relationship between plant-based nutrition and iron status. Additionally, emerging evidence suggests that the potential association between red meat consumption and cancer may be partially mediated by the high intake of heme iron. This review highlights the complex dynamics of dietary iron in vegetarian and vegan diets, which, despite offering less bioavailable iron, often surpass the intake levels of omnivorous diets. The potential involvement of adaptive physiological mechanisms suggests variability in non-heme iron absorption to meet nutritional requirements. While well-planned plant-based diets can be nutritionally adequate, further research is needed to better understand their long-term effects on iron metabolism.

Keywords: Anemia; Iron status; Non-heme; Vegan diet; Vegetarian diet.

Fig. 1

Systematic iron homeostasis Adapted from Galy, Conrad, and Muckenthaler [12]

Fig. 2

Role of chronic inflammation in iron homeostasis and anemia risk Adapted from Ganz & Nemeth [22]

Fig. 3

Factors regulating the bioavailability of non-heme iron