Oxalate
Oxalates are plant-derived salts (oxalic acid bound to minerals) that bind calcium in the gut and, in susceptible people, can form kidney stones or tissue crystals. Spinach, chard, beet greens, nuts, and chocolate are common high-oxalate foods.
Context
[edit]No specific Peat commentary naming oxalate or oxalic acid was found. His general framework for plant antinutrients (see Phytate) treats cooking and mineral balance, not blanket avoidance, as the practical response: boiling high-oxalate greens and discarding the water reduces oxalate content substantially, and pairing them with calcium-rich food limits how much free oxalate reaches the gut lining and kidneys.
Practice
[edit]Cook high-oxalate greens rather than eating them raw in large amounts; balance oxalate-heavy foods against adequate calcium and magnesium intake. People with a history of oxalate kidney stones need individualized medical guidance beyond general dietary rules.