How you cook your food is just as important as what you eat. When smoking, frying, or grilling meat, carcinogens are produced and when amino acids, sugars, and creatine react at high temperatures. That's right—grilling your meat can be as damaging to your body as smoking!
Certain cooking methods can also damage proteins. Denatured proteins (some of the biggest gut killers) which have lost their structure due to heat, aren't toxic in and of themselves. But the more heated a protein is, the more denatured it gets and the less likely it is that your body will be able to take advantage of its signaling molecules.
And, depending on which cooking style you choose, your strategy could oxidize fats. Fats are your friends, and it's important to be nice to them! As you know, polyunsaturated fats are highly reactive to heat and other chemical stressors. When heated, these oils produce compounds called dicarbonyls that cause cell mutations and may contribute to cancer.
Before you start cooking your meals, you need to know which cooking methods will create these toxins in your food. To simplify things, here is a list of the dangerous cooking methods (from least to most), so that you can avoid damaging your precious foods by cooking them the wrong way.
Simmering helps prevent fats from oxidizing, but it does tend to fully denature proteins. Simmering for a short period of time is fine, but leaving a bunch of meat on the stove to simmer for hours is not a good idea. Simmering is also a good option for vegetables as long as you don't overcook them.
This method of cooking food in a water bath can make meat literally melt in your mouth. I've had a sous vide setup in my kitchen for a decade. It's a great cooking method, but it does have a few downsides. The main risk is that BPA and other compounds can leach into your food from the plastic bags you use. The best way to avoid this problem is to use a glass jar packed fully, instead.
Just about every recipe you'll find for sous vide pays little attention to the biological effects of the cooking method. We honestly don't know what you get when you cook an artichoke at 160°F for 10 hours. Did you make it safer for consumption or less safe? Did the meat you cooked for 12 hours make it hot enough to prevent bacterial degradation and histamine? This is a fun way of cooking that produces amazing culinary results. See how you feel when cooking this way.
Lightly grilled (not charred)
This gives meat an unmistakable flavor and texture while keeping toxin formation to a minimum. The best way to grill your meat is so that the outside is just barely browned but the inside is still medium-rare to rare. This reduces the formation of toxins caused by charring meat while still giving your meat that wonderful grilled flavor and texture.
Slow cooking is an easy and time-efficient way to prepare meals, but it does have a few downsides. Long, slow cooking breaks down collagen, making for soft, delicious meat dishes. However, it can also produce glutamate and overcook meat. That's why you have to slow cook correctly. Keep it tightly covered and use lots of antioxidant spices like turmeric and rosemary, and consider adding some ascorbic acid (vitamin C) powder if you're planning to simmer something for several hours.
Broiling uses high heat from all sides to brown meat, which denatures the proteins more than other cooking methods. Broiling also oxidizes fats and causes glutamate to form outside the meat while destroying more nutrients in your food than other cooking methods. It's okay to make a broiled dish every now and then, but it shouldn't be your default cooking method.
While barbecuing meat over an open flame or grill makes it taste great, it also causes a few serious problems. When the fats hit the coals, they form cancer- and inflammation-causing HCAs and PAHs. Most barbecue sauces have hidden sugar and MSG, too (so watch out for these 20 secretive names for MSG). In most cases, you can get a similar taste and texture from low-temperature grilling, which produces fewer performance-robbing toxins, and by making your own Bulletproof barbecue sauce.
Burnt, blackened, or charred
Burning, blackening, or charring meat oxidizes the fat molecules, making them inflammatory. Oxidized fats also disrupt hormonal signaling, which can make you less sensitive to insulin, and thus, fatter. These methods also denature proteins, which makes them irritating to your immune system and harder to digest. They also produce mutagenic and carcinogenic substances.
Finally, these cooking methods produce glutamate, a neurotransmitter that in large amounts overexcites brain cells to death. All of these things decrease your mental and physical performance and may even make you age faster. Never eat blackened meat.
Deep-frying is one of the worst ways to cook your food, as it bathes your food in oxidized fats, denatured proteins, and glycated sugars. The high temperatures used during deep-frying produce a number of toxic compounds that may increase your risk of cancer.
Microwaved food is fully denatured, and one (albeit controversial) study showed that microwaves cause changes in HDL, LDL, and white blood cells. Microwave ovens also tend to create high amounts of electromagnetic fields in your kitchen.