HSPH Study Shows Protein-Free Diet Before Surgery Might Reduce Health Complications

Researchers from Harvard School of Public Health found that limiting protein or amino acid intake several days before surgery may reduce the risk of surgical complications.

According to the School of Public Health study, published in Science Translational Medicine, dietary intake of amino acids and protein before surgery might increase chances of health complications such as heart attack or stroke.

“We were interested in picking apart...what’s missing in the diet,” said James R. Mitchell, assistant professor of genetics and complex diseases at the School of Public Health. “What are we eating that we shouldn’t be eating?”

Previous studies over the past few decades have suggested that long-term dietary restrictions can extend longevity and slow the aging process. A recent study also demonstrated the benefits of restricting protein with fruit flies.

“What we found was that a brief dietary intervention in a mouse could protect against [surgical complications],” Mitchell said. “We wanted to know what the nutritional and genetic basis of that protection is.”


Researchers analyzed two groups of mice, with one group allowed to eat normally for 6 to 14 days while the other group ate an amino acid or protein-free diet.

When both groups were placed under surgical stress, 40 percent of the mice with a normal diet died. All of the mice with amino acid and protein-free diets survived.

According to Mitchell, he said he plans to further elucidate the nutritional basis and the underlying genetic mechanisms behind the study’s discovered link.

“Currently, there are no nutritional guidelines in and around the time of surgery. It’s just not a part of medical management specifically,” Mitchell said. “We think this might be an opportunity that, if this works in people...we can reduce stress resistance in the human body by a simple dietary restriction.”

Mitchell said that before this research can be translated to the clinical level, his team of researchers still needs to determine the optimal diet—and how long it should be maintained—for it to be effective.

-Staff writer Cynthia W. Shih can be reached at