Green smoothies are often made with leafy greens like spinach and kale. While these ingredients are packed with nutrients, ...

At first glance, the vibrant, pink stalks look almost like sunburned celery, but rhubarb is in a category of its own.

The reason, according to Asprey, is oxalates—naturally occurring compounds in many plant-based foods. “When you eat foods high in oxalate, they form razor-sharp microscopic calcium crystals ...