Listening to my iPod and reading from Real Food: What to Eat and Why (Nina Planck).

From pg. 200:

How Fake Butter Causes Heart Disease

In the last century, the American diet changed radically, but how it changed might surprise you. Given that heart disease began to be a problem around 1950, you might guess that we eat more saturated fats than we did in 1900. But in fact we eat less butter, lard, and beef and vastly more polyunsaturated oils now. In another way, however, the assumption that we eat more “artery-clogging” saturated fats is dead right: today we eat an industrial saturated fat that didn’t exist in 1900. Before World War II, Americans ate about 12 grams of trans fats daily, by 1985 as much as 40 grams. Since the 1970s, Americans have eaten roughly twice as much margarine as butter. For a major cause of heart disease, look no farther. Lard and butter “aren’t public enemy No. 1 anymore,” says Dr. Frank Hu of the Harvard School of Public Health. That designation now belongs to trans fats.

According to Dr. Walter Willett at Harvard, trans fats cause up to one hundred thousand premature deaths annually from heart disease. Compared with saturated fat, trans fats raise triglycerides, reduce blood vessel function, and raise lipoprotein (a) (Lp(a)), which causes clots and atherosclerosis. They raise LDL and reduce HDL. Willett says trans fats are twice as bad for the HDL/LDL ratio as saturated fats. Even experts who are cautious about saturated fats agree that butter is better.

And from pg. 203:

Recall that all of your cell walls are made of fat. Like natural fats, trans fats enter the tissues and become part of the cell membrane, where, unlike natural fats, they disrupt every cellular activity, from metabolism to immunity. Hundreds of thousands of Americans are walking around with cell walls made of trans fats, which have no place in the diet or body. The deadly effect of industrial trans fats will be with us for some time. The sooner we ban trans fats–as Denmark has  done–the better.

An alternate title for this book could be: How I Learned to Stop Worrying and Start Loving Animal Fat.