For cancer patients, doctors often recommend eating more protein to help fight weight loss and fatigue. But a new study from Boston University suggests that very high-protein diets could come with a hidden risk: an increased chance of dangerous blood clots.
The study, published in Blood Advances, looked at experimental models of colon cancer. Researchers found that diets high in protein, and especially those rich in the amino acid tryptophan, led to more severe blood clot formation compared with a balanced diet. Blood clots, known as venous thromboembolism (VTE), are a leading cause of death in cancer patients after the disease itself.
“Although our new findings are based on experimental models, we believe that knowledge gained from this study could prompt interest in further testing relevance to the human condition,” said senior author Dr. Katya Ravid of Boston University.
The results raise important questions for cancer care. Patients are often advised to increase protein intake, sometimes receiving intravenous nutrition that provides five to eight times more tryptophan than typical recommendations.
“Patients with cancer are often advised to increase their dietary protein intake,” said co-author Dr. Vipul Chitalia. “At times, these patients receive parenteral nutrition … including approximately five to eight times more [tryptophan] than dietary recommendation.”
The researchers caution that more work in humans is needed, but the findings highlight the need for carefully balanced nutrition plans in cancer treatment; enough protein to support strength, without increasing cardiovascular risks.
This research was supported by the American Heart Association, the National Institutes of Health and the Boston University Thrombosis and Hemostasis Research Collaborative.