Doctors and nutritionists have long recommended avoiding all animal fats to trim cholesterol, but Danish researchers report that cheese may not be so bad, and probably shouldn't be lumped in the same category with butter.
Their study, published in the American Journal of Clinical Nutrition, found that people who ate daily servings of cheese for six-week intervals had lower LDL, or "bad" cholesterol, than when they ate a comparable amount of butter. The cheese-eaters also did not have higher LDL during the experiment than when the same subjects ate a normal diet.
Dr. Elizabeth Jackson, assistant professor of medicine at the University of Michigan Health Systems, told Reuters Health that the study was well done, but does not really change what cardiologists currently recommend.
"We want people to have a diet focused on whole grains and vegetables and moderate fats," said Jackson, who was not involved in the work.
The researchers, from the University of Copenhagen in Denmark, set out to learn what effects cheese and butter had on heart disease risk factors, such as HDL, or "good" cholesterol, LDL and total cholesterol levels.
The researchers followed about 50 people who answered ads in local newspapers. Each person was put on a controlled diet and added a measured amount of cheese or butter daily.
Throughout, each participant was compared against his or herself, to follow the changes in the body caused by the foods.
Researchers gave each person cheese or butter, both made from cows milk, equal to 13 percent of their daily energy consumption from fat.
During six-week intervals, each person ate the set amount of cheese or butter, separated by a 14-day cleansing period in which they returned to their normal diet. Then they switched, and for six weeks those who had eaten the cheese before, ate butter, while the butter eaters in the first phase changed over to cheese.
Despite eating more fat than had been in their normal diet, the cheese eaters showed no increase in LDL or total cholesterol. While eating butter, however, the same subjects had LDL levels about seven percent higher on average.
While eating cheese, subjects' HDL cholesterol dropped slightly compared to when they ate butter, but not compared to their normal eating period.
The authors speculate there could be several reasons why cheese behaved differently than butter, but nothing conclusive.
For one, cheese has a lot of calcium, which has been shown to increase the amount of fat excreted by the digestive tract.
The researchers did detect a little more fecal fat during the time the group ate cheese, but the amounts were not statistically significant.
Other possible explanations involve the large amount of protein in cheeses and its fermentation process, both of which could affect the way it's digested compared with butter.
The study was supported by the Danish Dairy Board and the National Dairy Research Institute.
Jackson cautioned this one study does not mean people should start eating endless amounts of cheese. "In terms of cheese, anything in moderation," she said.