I first saw this story when Peter over at the Hyperlipid blog pointed to it. He had seen the story reported on Yahoo News Fast-food binge harms liver, but boosts good cholesterol: study
PARIS (AFP) - A month-long diet of fast food and no exercise led to dangerously high levels of enzymes linked to liver damage, in an unusual experiment inspired by the docu-movie "Supersize Me."The study is reported in the Journal GUT:
But investigators, reporting their findings on Thursday, were also stunned to find that a relentless regimen of burgers, fries and soda also boosted so-called good cholesterol, seen as a key measure of cardiovascular health.
Researchers in Sweden asked 12 men and six women in their twenties, all slim and in good health, to eat two meals per day at McDonalds, Burger King or other fast-food restaurants over four weeks.
Fast food based hyper-alimentation can induce rapid and profound elevation of serum alanine aminotransferase in healthy subjects
Objective To study the effect of fast food-based hyper-alimentation on liver enzymes and hepatic triglyceride content (HTGC).
Design Prospective interventional study with parallel control group.
Setting University Hospital of Linkoping, Sweden. Participants 12 healthy men and six healthy women with a mean (SD) age of 26 (6.6) years and a matched control group.
Intervention Subjects in the intervention group aimed for a body weight increase of 5-15% by eating at least two fast food-based meals a day with the goal to double the regular caloric intake in combination with adoption of a sedentary lifestyle for four weeks.
Main outcome measures Weekly changes of serum aminotransferases and HTGC measured by proton nuclear magnetic resonance-spectroscopy at baseline and after the intervention.
Results Subjects in the intervention group increased from 67.6 (9.1) kg to 74.0 (11) kg in weight (p<0.001).>19U/l, men >30U/l) during the intervention. Sugar (mono- and disaccharides) intake during week three correlated with the maximal ALT/baseline ALT-ratio (r=0.62, p=0.006). HTGC increased from 1.1 (1.9) % to 2.8 (4.8) %, although this was not related to the increase in ALT levels. ALT levels were unchanged in controls.
Conclusion Hyper-alimentation per se can induce profound ALT elevations in less than four weeks. Our study clearly shows that in the evaluation of subjects with elevated ALT the medical history should include not only questions about alcohol intake but also explore whether recent excessive food intake has occurred.
Peter points a couple of interesting things from the story:
"It was not the fat in the hamburgers, it was rather the sugar in the coke," he said.
But the most startling result implies that an intensive fast food diet might have some health benefits too, apparently from fat.
"We found that healthy HDL cholesterol actually increased over the four-week period -- this was very counter-intuitive," said.
HDL, sometimes called "good cholesterol," seems to clean the walls of blood vessels, removing excess "bad cholesterol" that can cause coronary artery disease and transporting it to the liver for processing [in the fairyland of the lipid hypothesis that is, Peter].
It is interesting to see how this has been reported elsewhere:
MedPage today says: Explain to interested patients that this small study suggested that overdoing it on high-fat foods, even during a short holiday period, for instance, and a failure to exercise can cause liver damage.
eh? the researchers said it was the sugar not the fat
NHS Choices says: The study does provide a further reason to avoid overeating (especially food high in saturated fat) if one is needed.
er...the researcher said that "The study showed that the increase in saturated fat correlated with the increase in healthy cholesterol,"
You wouldn't realise it from the way in which it is reported, but it looks like saturated fat is good and sugar is bad!