Is cooking with cast iron healthy?
Yes, cooking with cast iron is healthy. Cast iron is naturally chemical-free, so no matter how long you use your skillet or how hot you get it, you won’t consume any unhealthy chemicals.
Additionally, cast iron adds iron to your food. Cooking food on a cast iron skillet can provide as much as 20 times your daily intake of iron, which can be particularly beneficial for women, children, and vegetarians, who are all more prone to iron deficiency.
Further, because cast iron cookware is non-stick, you can use less oil and saturated fats when cooking. Cooking with less oil will improve heart and cardiovascular health over time.

Related Questions
Cook more healthily
Most people think of seared meat and fried food when they think of cast iron skillets, but due to their excellent heat retention, cast iron pans and cookware are great for healthier cooking methods like braising and poaching, and can even be used in the oven!