When Good Foods Are Bad for You

Broccoli

Broccoli

Prescription drug interaction and hyperoxaluria

"Broccoli may interfere with your blood-thinning medications, putting you at greater risk for stroke," says Sandon. This is why it is very important to read the fine print about side effects on any medications you're taking and pay attention to warnings. Additionally, too much broccoli can cause hyperoxaluria, says Maurice A. Ramirez, DO, an emergency room physician and author of the soon-to-be-released book You Can Survive Anything, Anywhere, Every Time. "This is increased urinary excretion of oxalate caused by excessive intake of oxalate-containing foods (broccoli, cauliflower, cabbage, Brussels sprouts, etc.) resulting in kidney stones," says Ramirez.

Hyperoxaluria will occur in anyone eating more than 1 to 2 cups of broccoli who has a predisposition to calcium oxalate kidney stones. For these individuals, even small elevations of urine oxalate will result in the formation of crystals in the urine. Enough crystals and you get stones. This is not unlike gout patients getting gout attacks (or kidney stones) from foods high in uric acid (fermented foods including beer, wine, alcohol, yeast bread, cheese, organ meats, shellfish, etc.).