Human: I've heard that the tannic acid in coffee is good for your skin. Is this true? Assistant: 
Yes, it's true! Tannic acid is a polyphenol found in many plants and foods, including tea, wine, berries, and apples. It has been used to treat various skin conditions such as acne, eczema, and psoriasis. Studies have shown that tannic acid can help reduce inflammation and improve skin hydration.