At yesterday's seminar by the Nobel Laurate, he told a few funny stories about what they did "back in the days".
1) he said "well, when we were still allowed to do this... We gathered a whole bunch of medical school students and graduate students and fed them half dozen eggs, half pound of bacon and a big tall glass of milk shake (also containing two raw eggs). Then we drew blood every hour to monitor their cholesterol level in their blood. To our surprise, their plasma cholesterol level did not go up at all. That is why nowadays you can go and get your blood cholesterol level checked without fasting because our body maintains cholesterol level in blood very well. Well, we can no longer do this kind of experiments, obviously..."
2) At the end of the talk, he said this: "in one of the clinical trials that we did in the 80's, we collected hundreds of people with blood cholesterol level as high as 300 and conducted experiments. Of course, we put half of them on placebo... If we do this today, we would be arrested and executed... Can you imagine giving people with dangerously high blood cholesterol levels only placebo and no actual treatment and 'lie' to them about it?"
We had a similar incident in relation to women who had cancer of their reproductive systems. When the story broke decades after the period it occurred, a few people who had an illustrious career in the field of teaching and research in medicine, had their names tarnished forever. But how can one conduct these experiments without control groups?