Calcium Oxalate Crystals as Raw Food Antinutrient: A Review

The nutritional value of food can be altered by the presence of antinutrients such as oxalates present abundantly in plants as ergastic crystals. High oxalate content in plant-based raw food can lead to oxalonephropathy, nephrolithiasis and renal dysfunction. Presence of oxalate can hinder the absorption of other minerals such as calcium and magnesium present in food. CaOx antinutrient intake can be minimised by avoiding plant with high oxalate content or by decreasing oxalate levels through cooking practices like, boiling, fermenting, treating with baking soda, adding yoghurt and milk etc. More sophisticated ways of minimising antinutrient intake through raw diet is by choosing genetically modified crops which are bred for low oxalate content or by choosing mutant varieties which are devoid or low in oxalate content in food crops. The future for sustainable antinutrient management and nutritional value enhancement is by incorporating genes from bacteria or fungi which are capable of breaking down oxalate using the enzyme oxalate decarboxylase, on to plants and thereby modifying them to have less antinutrient effects in raw consumption.