The complete guide to cooking oils and how they affect your health By Jasmin Fox-Skelly Whether you are roasting a chicken in the oven, browning onions in a frying pan or choosing a spread for your toast, oils are at the heart of our culinary activity. We have a dizzying array of choice. From sunflower to flaxseed, avocado to coconut, around 30 varieties of oil are now used for cooking. Your decision on which to use could have a profound effect on your health, with consequences for your cholesterol, blood pressure and risk of cardiovascular disease. If you believe the headlines, then palm oil is out, sunflower oil is on shaky ground and there seems no end to the benefits that extra virgin olive oil brings to the table. But are these claims backed up by solid science?