This is an on-going debate. We don’t like giving up our preconceptions or our pleasures, so we resist some answers. But facts stay facts – see if you can trip me up on the science behind mine. (How’s that for confidence.)
The best type of cooking is steaming. You retain the most nutrients because you don’t lose nutrients into the water like you do when you boil food. You also don’t have as many carcinogenic chemicals developing as you do in long or fast cooking. The good news is that you never have to eat boiled liver again because it isn’t really that healthy.
Microwave cooking has a bad reputation with limited proof. Recent studies again show that it doesn’t kill off any more nutrients than normal cooking does. It does agitate the molecules harder and faster than normal cooking, but that hasn’t been related to any negative results yet. I do presume that it probably does kill off any beneficial bacteria, but I doubt many of those survive steaming either. Of course the machine itself has to be well-maintained to be safe, but that’s a different discussion.
Cooking food quickly at high temperatures or for too long causes chemical reactions in the food that are carcinogenic. That means that fried and grilled food isn’t good for you, eat it in moderation.
What practical results can you take from this?
* Poach or boil eggs rather than frying.
* Pre-prepare meat in the microwave rather than only grilling it to cut down its exposure to heat.
* Turn what you’re cooking often if you are grilling or frying so that the heat stays as gentle as possible on both sides.
* And the hardest for me to accept … don’t make gravies from the bits left in the bottom of the pan, particularly not if some of the bits are charred.
Should you cook your vegetables or not? Who’s right? The people who cook or the Raw Foodies? The answer, typically, is completely individual – it’s dependent on both the specific food-type and your digestive system. A rule of thumb is that the more processed a food is, the more nutrients it loses. Vitamin C is practically destroyed by heat but other nutrients are more heat stable and some like lycopene benefit from longer cooking.
Some people need to have their food cooked to assist with their digestion, others thrive on raw foods. In general aim for some cooked and some raw every day to get the best of both? It’s best to experiment with what works for you, but don’t be inflexible. Our bodies change with time, and you need to change with it to do what’s best for you rather than blindly following a philosophy.
Note that cooking foods with a high anti-nutrient value like lectins or oxalates is different. There are tricks to negating the negatives effects of the anti-nutrients in your preparation and cooking techniques, but that’s for anther time.
I’ve heard from informed sources that if you’re grilling meat it’s best to quickly sear the outside and then cook it more slowly once sealed. The seared outside bits are carcinogenic and should be avoided. The inside retains flavour and juices due to the searing, but is less carcinogenic. See, I said you wouldn’t like it but it makes sense. I don’t have scientific research for this one, just logic.