Protein and carbohydrate are only two of the three macronutrients everyone needs for good health. Fat is the third. Fat provides a lot of energy in a small package, and calories from fat can literally be life-saving in some situations.
Do cancer patients need to worry about lowering their fat intake and losing weight? Generally speaking, if you are suffering loss of appetite, nausea, or vomiting during cancer treatment, you really don't need to worry about fat in your diet or weight control.
That doesn't mean that every kind of fat is healthy for you. All trans- fats are bad, but some trans- fats are worse. If you cannot avoid all foods with trans- fat, consider avoiding the very worst.
What Makes Trans- Fat Bad Fat. The bloodstream “throws” fat at cells much as an archer might shoot an arrow. A long, straight arrow enters the cell with ease. It causes minimal disruption to the flow of electrical charges across the surface of the cell. A lumpy, short arrow, or, even worse, a lumpy long arrow, sticks in the cell’s protective coat and interrupts the flow of information across its surface.
Some dietary fats are long and straight, others are short and lumpy, and still others are combinations in between. The “lumpiness” of a fatty acid depends on the way its carbon atoms are arranged, that is whether the carbon “shaft” of the arrow is cis- and. On an atomic level, fatty acids are made of parallel chains of carbon. Cis- fatty acids have lines of carbon neatly aligned in parallel.
C – C – C – C – C – C
C – C – C – C – C – C
The comparatively healthy cis- fatty acids slip neatly into the cell without disturbing the cell membrane. They are not as easy for cell to absorb because they are a "short arrow." But they do not disrupt the health of the cell.
Trans- fatty acids, on the other hand, contain carbon atoms at various points in their chains that “elbow” other molecules in the lining of the cell out of the way.
C – C – C - C – C
C – C – C - C – C
A short, bent arrow might do minimal damage to the cell but a long, bent arrow is devastating. Trans- fatty acids are made during the manufacturing of margarine, allowing to be stored and used in a solid form, during the process of frying vegetable oils, and by bacterial action in the stomachs of cows, sheep, and goats. Beef, lamb, and chevron (goat meat) contain much smaller quantities of trans- fatty acids than margarine or fried foods.
The Worst of the Bad Fats. Generally speaking, all trans- (“bent” or “lumpy”) fatty acids are bad, but some trans-fatty acids are worse. Trans-fatty acids with 16 carbons or fewer tend to slip into the cell without damaging the membrane. At least one study found that victims of sudden death were no more likely to have deposits of these so-called 16:1 fatty acids (the 1 refers to the number of double bonds between carbon atoms) than healthy individuals. A supposedly “good,” cis- fatty acid with 16 carbons, palmitic acid, the fatty acid found in palm oil, is in fact more likely to be associated with sudden death than any “bad” trans- fatty acid!
The 18:1 fatty acids, an 18-carbon long fatty acid with one “kink” in the carbon chain, are also found in abundance in the hearts of victims of sudden death. The foods that supply these dangerous fatty acids include:
▪ Bakery-made chocolate cookies made with cottonseed and/or soybean oil
▪ Chocolate cookies with crème fillings
▪ Commercial taco shells
▪ Glazed doughnuts
▪ Milk chocolate coated cookie bars made with caramel
▪ Popcorn made with soybean oil (although low-fat varieties contain 80 percent less 18: fatty acids)
▪ Potato chips fried in a mixture of oils (but not potato chips fried in just one kind of oil)
▪ Shortening, especially if it is made with soybean oil (28 times the 18:1 fatty acid content of lard)
▪ Snack crackers made with cottonseed oil, refined coconut oil, or soybean oil
By comparison, lard, pure butter, pork rinds, frankfurters, tortilla chips, pudding pops, and white bread, none of which is a health food (and none of which is recommended for your daily diet), are better for your heart.
Margarine is especially detrimental to heart health. Margarine made with soybean oil has 22 times the 18:1 content of pure lard. Margarine made with corn oil has 23 times the content of this dangerous fatty acid. Margarine made from cottonseed oil is even worse, containing 24 times the 18: 1 trans- fatty acid found in lard. A study of women with breast cancer by the University of Massachusetts Medical School found that women eating the most margarine and similar foods were from 17 to 129 per cent more likely to die at every stage of the disease.
There are fats that are even worse for general health. An 18-carbon fatty acid can also have two double bonds. These 18:2 fatty acids even more harmful to heart health as the fatty acids that have 18 carbons and one double bond, since they have two “kinks” that can get “caught” in the cell membrane. Trans- 18:2 fatty acids are found in pizza, fried chicken, and cookies.
These fatty acids are the most harmful to heart health—and at least one epidemiological study was able to predict risk of sudden death by consumption of pizza, fried chicken, and commercially prepared cookies alone. These fatty acids are also abundant in cottonseed and soybean oil margarine and shortening and in potato chips fried in cottonseed or soybean oil.
There are also some trans- fatty acids that are not quite so bad for you. Trans- 16: 1 fatty acids are almost as bad as the longer-chain 18:1 fatty acids, although they are less than 1/10 percent as abundant in food. Trans- 16:1 fatty acids are found in very small quantities in hamburger, sausage, and turkey used in luncheon meat. Because they are not as long as the 18: 1 fatty acids, they are less likely to get “stuck” in the lining of the cell and more likely to “bounce off.”
Supposedly healthy cis-16:1 fatty acids, with a straight chain, however, are much more likely to contribute to arrhythmia than their longer cousins that “slide” through the membrane. In fact, they are worse for heart health than the fatty acids found in doughnuts, chocolate chip cookies, and commercial popcorn. Cis 16:1 fatty acids occur in highest concentrations in chicken skin and visible fat in turkey, although these foods contain less than 1/5 the concentration of heart-harmful fatty acids as margarine, and in much lower concentrations in lard and beef bologna.
In summary, the dietary no-no’s for people with cancer are margarine, snack crackers, commercially prepared cookies, chips fried in soybean oil, doughnuts, and, to a much lesser extent, chicken skin, pizza, cold cuts, and any kind of ground poultry unless it is low-fat. (That is, don’t eat ground turkey that contains ground turkey skin.) Notice what is not on this list: Butter, most fried foods, most meats, dairy products, and desserts, eaten occasionally in moderation. Many people have other health reasons to avoid these foods, but getting over cancer is not one of them.