The Wienerschnitzel was so large it hung off the plate. Topped with a sprinkling of chopped parsley and lemon juice, it was an absolute treat. To this day, my mouth waters whenever I recall my first schnitzel experience. My aunt, who had arranged for us to come to Montreal after we had fled Hungary during the 1956 uprising, owned the 鈥淩iviera,鈥� a European style restaurant. It was there that I was introduced to the delights of a serving of veal, pounded almost paper-thin, battered in flour, eggs聽and breadcrumbs, and quickly fried to a golden brown. I just loved it. In fact, I still do. The Riviera is long gone, but I have learned to make a pretty acceptable schnitzel myself. But there is a difference. Science has now聽entered the picture and my enjoyment is now tainted by nutritional concerns. As much as I hate to admit it, some pretty dark clouds hang over the frequent consumption of red meat and fried foods in particular.
The words 鈥渞ed meat鈥� and 鈥渃ancer鈥� now appear in the same sentence in the scientific literature with alarming frequency and articles about the role of diet in cancer commonly conclude that many cases can be prevented by dietary modification. The suggested changes usually involve increasing fruit and vegetable consumption while curbing the intake of red meat and foods cooked at a high temperature. Take, for example, a huge European study that enrolled almost half a million healthy men and women in the 1990s and followed their health status. After about five years, some 1300 cases of colorectal cancer had been detected and the lifestyles of these patients were then compared with those free of the disease. The major finding was that bowel cancer was associated with an intake of red meats and processed meats. Quantitatively, people who ate more than 160 grams of red or processed meat a day were 35% more likely to develop bowel cancer than those who ate less than 20 grams a day. And 160 grams is not a lot, eat a 鈥渜uarter pounder鈥� and you鈥檝e got it. Chicken was not implicated and eating fish was actually associated with a lower risk of bowel cancer.
Exactly what the problem is with red and processed meats is hard to say, but it鈥檚 a good bet that heterocyclic amines (HCAs) are involved. Heating food unleashes a host of chemical changes, some of which, such as destroying bacteria, softening muscle fibers and developing flavour are desirable, while others are not. High temperatures allow compounds such as creatinine in meat to combine with aldehydes (glucose, for example) to form heterocyclic amines, which are recognized carcinogens. The higher the temperature, the longer the cooking time, the more HCAs form. And these compounds have been implicated in more than bowel cancer. Red meat consumption is associated with prostate, stomach聽and pancreatic cancer, and researchers have also found that women who routinely eat very well done meat face a five-fold increase in breast cancer risk when compared with women who eat their meat rare or medium. Why chicken and fish are less risky isn鈥檛 clear but it may have to do with shorter cooking times. In any case, this is a welcome observation because chicken and particularly fish, are also deemed to be more heart-healthy than red meat. At least as long as they are not fried! Harvard Medical School researchers who examined the heart function of some 5000 seniors found that those who ate broiled or baked fish frequently had lower heart rates, lower blood pressure and better blood flow to the heart while those who regularly ate fried fish or fast-food fish sandwiches actually showed a greater incidence of hardening of the coronary arteries and other heart problems. The likely culprit here is the fat used for frying.
I don鈥檛 know what the cooks in the Riviera used to fry my Wienerschnitzel back in the 1950s, but it was probably some sort of animal fat. As scientists learned more about the cholesterol-raising properties of such saturated fats, they pushed to replace them with the polyunsaturated fats found in vegetable oils. These, though, degraded more easily when heated and could not be reused as often as the saturated fats. A remedy was found in the form of 鈥減artially hydrogenated鈥� vegetable oils which had better keeping qualities, but alas, a new problem cropped up. Hydrogenation converted some of the unsaturated fats into the now notorious 鈥渢rans fats,鈥� which were as bad for the heart as the animal fats. Today, trans fats have become a pariah and movements are afoot to drive them out of our food supply. But what do we replace them with? Going back to beef tallow or lard is hardly the answer. Frying in unsaturated vegetable oils eliminates the trans fat problem but let鈥檚 not get too comfortable with these either. There is the emerging issue of trans-4-hydroxy-2-nonenal, or 鈥淗NE.鈥�
Chances are you haven鈥檛 heard of HNE, but it is causing somewhat of a ruckus in the scientific community. HNE forms when polyunsaturated fats, that is those containing several carbon-carbon double bonds, react with oxygen. Such fats are present in cell membranes and can give rise to HNE which then can travel through the bloodstream. The bad news is that HNE has been linked with cardiovascular disease, Parkinson鈥檚, Alzheimer鈥檚, liver and kidney ailments, and even cancer. And here is what we really don鈥檛 want to hear: HNE forms when polyunsaturated oils, particularly those containing linoleic acid (corn, soy, canola), are heated, especially if heated repeatedly. Those golden fries in restaurants may be laden with HNE! Now for the good news. Monounsaturated fats like peanut oil or olive oil are far less prone to such contamination. Alas, these are not commonly used in restaurants so limiting fried foods when eating out is really important. But I still won鈥檛 give up on making my Wienerschnitzel at home. I do it less often and fry it in olive oil. Why? Because there is more to life than worrying about every morsel of food we put into our mouth.
