This has always attracted us to the latest dietary fad. Low fat, low carb, the leptin diet – you name it and some of us have experimented with it.
More and more, however, we are turning to science and controlled experimentation for our dietary advice. I sense that this is explains the great interest that people with diabetes have in the glycemic index.
Emerging science is now concerned with cooking foods at high temperatures. This is unhealthful because it dramatically increases the production of advanced glycation end products (AGEs). These compounds in the blood stimulate cells to produce inflammation-causing proteins.
It’s possible that a diet low in AGEs can help control our diabetes, suggests AGEs researcher Joe Anderson in recent correspondence with me. He is the primary author of a remarkable new synthesis of the evidence about the effects of AGEs. Joe tells me that he is a research engineer working with an MD and another research engineer.
Heating food to more than about 240 degrees Fahrenheit causes a rapid increase in AGEs and generates damaging fat and sugar oxidation products, he says. “AGEs, usually indicated by browning, have intense, tasty flavors humans like to eat.”
That’s the crux of the problem. So Joe’s mantra is “If it’s brown, put it down.”
Don’t use fried, barbecued, broiled, or baked foods, especially if they contain sugar, he says. “Do use fresh, raw, steamed, stewed, poached, boiled or lightly sautéed foods.”
Using a microwave is fine, he tells me. “Microwaves are lousy at browning. That’s good! Like all cooking, its better to cover so steam builds up, which evens out the heating effects, and the steam helps exclude oxygen, which also helps reduce AGEs.”
The problem is not just over-heating sugar. Fat and protein can be just as serious a concern.
“It’s easily missed in the paper, but fats are really big-time AGE producers when cooked at high temperatures,” Joe tells me. “I’ll be posting some data soon. Vegetable fats contain very little saturated fats and they are usually cooked less severely. Since we Americans usually prefer roasted and broiled meats – and much of the fat is on the outside – the meat-based saturated fat gets really high in AGE content when browned. That may be the reason saturated fats are linked to health issues….It’s the AGEs generated from cooking, not the saturated fats themselves.
“Another, largely unrecognized, source of dietary AGEs is animal products from animals fed a high-AGE and/or an AGE-inducing diet. This probably includes most commercial poultry, grain-fed beef, and other animals that have high levels of AGEs and/or AGE inducers in their diet. Any ‘fattened’ animal has probably been fed such a diet since that is how rapid weight gain can be produced.”