Frying and trans-fatty acids

Frying should be generally avoided. This is because it involves high heat that grossly dissociates oils and fats, often rendering them carcinogenic. But of course, frying just as other high-heat cooking methods like broiling (grilling) and barbecuing are such delicious ways of having some of our foods, that vague warnings are not particularly useful. So let me be pragmatically specific.
You probably know that nutritionists advocate the use of unsaturated fats, since most of the processed foods we buy are choked with saturated fats. A bit of balance never did anybody any harm. But what happens when we fry with unsaturated seed oils? Well, at temperatures of 150 C (300 F) most unsaturated oils become mutagenic, that is, they can damage our genes and these of our offspring and of our entire family. Above 160 C (318 F) trans-fatty acids begin to form. Above 200 C (390 F) trans-fatty acids form in substantial quantities. Above 220 C (428 F) trans-fatty acids form at exponential rates.
So, what is wrong with trans-fatty acids, you will say. Aren’t some of our very best margarines, shortenings, and other convenience foods made out of trans-fatty acids? They certainly are. But this is a reason for avoiding them, not for becoming a manufacturer of trans-fatty acids in your own kitchen. For trans-fatty acids are twisted. As a well-known writer on fats has written, imagine having the top part of your body twisted back to front. You’d never know whether you are coming or going. Trans-fatty acids are an example of this problem at the molecular level. Let us discuss these fatty acids a little further.
Trans-fatty acids are misfits in the scheme of things. The change in shape from the normal bent cis- form to the straight line of the trans- form, is a wrench thrown in the works. The trans- form only half-fits into enzyme and membrane structures of biological systems, taking up the space of cis- forms, but incapable of doing the work of normal fatty acids. I.e. they are not only misfits; they are downright saboteurs of our wellbeing.
Then, there is an undesirable stickiness about trans-fatty acids. For example, cis-oleic acid melts at 13 C (55 F) and is therefore liquid at room and body temperatures. Trans-oleic acid melts at 44 C (111 F) and is solid at both room and body temperatures. The liquid form of olive oil has changed into a sticky solid form. Our platelets become naturally stickier, and the likelihood of blood clots correspondingly greater, causing strokes, heart attacks, or other circulatory occlusions in organs such as lungs, in our extremities, and various sense organs. Not a very brilliant way to prepare for a vigorous middle age and a healthy eldership.
Further, our enzymes break down trans-fatty acids at slower rates than cis-fatty acids. But the normal fuel of our heart is fatty acids. A high consumption of trans-fatty acids may compromise its feeding rate and impair its capacity. In situations of crisis, stress, or excessive energy demands, this could have fatal consequences. Are you still wondering why we are dropping dead from heart attacks, as if other forms of death were going out of style?
Equally, trans-fatty acids damage cell membranes, so that some molecules normally kept out can now get in, while others required in the cell can now get out. This inevitably devitalizes our cells. It also reduces our immune function, while it leaves the door open for allergic reactions. Are you aware of how fast our food and other allergies have increased during the past half-century?
One could go on and discuss how trans-fatty acids disrupt the normal and vital function of essential fatty acids (EFAs); how they change the molecular architecture of our bodies and interfere with energy flow; how they produce electrical short-circuits by being unable to take part in electron exchange reactions, and so on. But surely, by now you understand why you should not fry foods in seed oils, or use hydrogenated solid convenience foods. They may be convenient in the kitchen and on the table, but now you also know how inconvenient they are to our body cells.
Should you then fry with saturated fats? Believe it or not, they behave somewhat better under conditions of high heat. But since our foods are already choked with saturated fats, consciously choosing to eat more of the same is surely schizophrenic. We should try to limit saturated fats, not increase their consumption for the sake of a cooking method, where the heat used is perilously high. When a food turns brown, this is not a sign that it is done, but a warning that it is being burned. Proteins turn into carcinogenic acrolein. Starches and sugars too, are browned through molecular destruction. Fats and oils turn to smoke by the destruction of fatty acids and glycerol. So, what is a safe frying method?
That is a contradiction in terms. But that is also where this other contradiction about the Greek frequency of frying and their corresponding health mentioned at the beginning, may be explained. Monounsaturated fats like olive oil are a lot more resistant to high heat than polyunsaturated seed oils, deteriorating slowly, but will not burn up to temperatures of 260-285 C (500-550 F). The Greeks traditionally fry their foods in olive oil, and this is the least harmful way of frying. But now you can do even better than your Greek friends, by gently stir-frying many foods for a couple of minutes, using the preparation and cooking techniques of the Chinese wok. Adding a bit of water to the wok at the very beginning, will keep the temperature of frying appropriately low.