Assessment of oxalates and phytic acid contents in Asian green leafy vegetables: Dietary recommendations

Abstract

Increased vegetable consumption is one of the recommended dietary interventions for optimal health but there is a lack of documentation about their anti-nutrients content, such as oxalates and phytic acid, which can modulate other health risks such as mineral deficiencies and urinary stone formation. The objective of this study was to evaluate the oxalates and phytic acid content of 26 green leafy vegetables (GLV) indigenous to and commonly consumed in Asia to expand existing nutritional information on food sources. The total oxalate contents ranged from 6 ± 0.2 mg/100 g fresh weight (FW) (iceberg lettuce) to 557 ± 47 mg/100 g FW (spinach), while the soluble oxalate contents ranged from 2 ± 0.3 mg/100 g FW (iceberg lettuce) to 501 ± 36 mg/100 g FW (turmeric leaves). The phytic content of the GLV ranged from 6 ± 2 mg/100 g FW (celery) to 111 ± 16 mg/100 g FW (moringa leaves). Overall, the anti-nutrients data have provided an increased understanding of these Asian GLV which will be important for nutritional and healthcare professionals to improve the dietary regime of the population. Data will also allow general consumers to make informed choices on how best these GLV can contribute to optimal health.