Part of the benefit may be due to what you’re not doing when you slow cook food: frying or burning. But setting off the smoke alarm and ruining the pans isn’t the only reason we should stop cooking this way.
When we heat proteins such as meat or fatty foods at high temperatures, they produce substances called advanced glycation end products (AGEs) which can have a damaging impact on our health. Although AGEs accumulate in our bodies naturally as we age, the biggest contributor is through what we eat.
Your body can eliminate most AGEs, but if you eat too many it can’t keep up and this leads to oxidative stress and chronic inflammation. As a result, high levels of AGEs are associated with the development of many chronic diseases such as high blood pressure, diabetes, cardiovascular disease, liver disease and kidney failure. The levels measured in your blood may even predict mortality. In one study of 559 older women, those with the highest levels of AGEs were almost twice as likely to die with cardiovascular disease than those with low levels.
Even if you are eating a fairly healthy, balanced diet you may be inadvertently consuming harmful amounts of AGEs. When browning food by grilling, frying, toasting, roasting, searing or barbecuing you not only add that tasty caramelised flavour, you also increase the level of AGEs by ten to 100 times compared with uncooked food. So if you regularly eat fried, grilled or roasted red meats, use oil at high temperatures or eat processed foods, you are likely to be a high consumer of AGEs.
But you can reduce your levels of inflammation and lower your risk of chronic diseases. This is where good old-fashioned ways of cooking with ‘moist heat’ come in – slow cooking, poaching and making soups and stews significantly reduce AGEs. Slow cooking also helps to retain nutrients usually discarded in the cooking water. Throw in extra veg, beans and lentils to up the fibre. You should also limit processed foods that often contain higher levels of AGEs, and counteract the damaging effects through eating foods high in vitamin C, quercetin found in apple skin, resveratrol in berries and grapes, herbs and spices such as turmeric, as well as plenty of colourful vegetables.
You can also try cooking ‘sous vide’ where food is vacuum sealed with flavouring then cooked at a low temperature in a water bath, leaving it tasty, nutritious and requiring little attention. Another way to reduce AGEs is by cooking or marinating with ingredients such as lemon juice or vinegar, which can lower them by half.
The message is: low and slow is probably best. Now I’m off to make a spicy vegetable stew in my slow cooker.
author: Dr Clare Bailey