Nuts high in iron
Pro Research Analysisby 
Searched over 200M research papers
Nuts High in Iron: A Comprehensive Analysis
Iron Content in Nuts and Oilseeds
High Iron Content in Nigre Seeds
Research has shown that among various nuts and oilseeds, nigre seeds contain the highest total iron content. This makes them a notable source of iron compared to other seeds like linseed, which have significantly lower iron levels .
Bioavailability of Iron in Nuts
While some nuts have high iron content, their bioavailability varies. Pistachio nuts and almonds have been found to have significantly higher bioavailability of iron compared to other nuts like groundnuts, which have markedly low bioavailability . However, it is important to note that most nuts and oilseeds generally have less than 10% bioavailability of iron, making them less effective as iron sources among plant foods .
Inhibitory Effects on Iron Absorption
Phytates and Polyphenols in Nuts
Nuts such as walnuts, almonds, peanuts, and hazelnuts contain significant amounts of phytates and polyphenols, which are known inhibitors of iron absorption. This results in a lower iron absorption rate from these nuts compared to other foods like bread . For instance, the geometric mean absorption from nut meals was found to be 1.8%, significantly lower than the 6.6% from bread meals .
Overcoming Inhibitory Effects
Interestingly, the inhibitory effects of certain nuts on iron absorption can be mitigated by the presence of ascorbic acid. For example, the addition of 50 milligrams of ascorbic acid was shown to overcome the inhibitory effects of Brazil nuts and peanuts on iron absorption .
Special Case: Baru Seeds
Nutritional Profile and Antioxidant Activity
Baru seeds, a native fruit of the Brazilian savanna, are rich in minerals, tannins, and phytic acid. They also exhibit high antioxidant activity, which can be beneficial in preventing iron-induced oxidative stress . Studies on rats have demonstrated that the consumption of baru seeds can reduce oxidative stress markers in the liver, heart, and spleen, suggesting a protective effect against iron-induced damage .
Phytic Acid and Phenolic Compounds
The protective effects of baru seeds are partly attributed to their high phytic acid content, which helps reduce oxidative stress. Additionally, phenolic compounds present in baru seeds contribute to their antioxidant properties, further enhancing their health benefits .
Conclusion
While certain nuts like nigre seeds and pistachios are high in iron, the overall bioavailability of iron from nuts is generally low due to the presence of inhibitors like phytates and polyphenols. However, the addition of ascorbic acid can improve iron absorption from some nuts. Baru seeds stand out for their unique ability to mitigate iron-induced oxidative stress, thanks to their rich content of phytic acid and phenolic compounds. Therefore, while nuts can be a part of an iron-rich diet, their effectiveness can be enhanced with proper dietary combinations.
Sources and full results
Most relevant research papers on this topic