Reducing the serum cholesterol level with a diet high in animal fat

Multiple food allergies required a group of seven patients with elevated serum cholesterol levels to follow a diet in which most of the calories came from beef fat. Their diets contained no sucrose, milk, or grains. They were given nutritional supplements. This is the only group of people in recent times to follow such a diet. During the study, the patients' triglyceride levels decreased from an average of 113 mg/dl to an average of 74 mg/dl; at the same time, their serum cholesterol levels fell from an average of 263 mg/dl to an average of 189 mg/dl. At the beginning of the study, six of the patients had an average high-density lipoprotein percentage of 21%. At the end of the study, the average had risen to 32%. These findings raise an interesting question: are elevated serum cholesterol levels caused in part not by eating animal fat (an extremely "old food"), but by some factor in grains, sucrose, or milk ("new foods") that interferes with cholesterol metabolism?