Be careful what the sardines come in. Sardines might come in olive oil, salt water brine, "spicy sauce" or something, etc. Try different types to see how you feel. Real olive oil is good, but a lot of olive oils are becoming fake "olive" oils with mostly seed oils. I would be a bit suspicious of tomato sauces and spicy stuff having extra ingredients. I guess brine might be safest.
Discussion
Agreed, a big reason why I stopped was most cans use olive oil or some other seed oil