Restricted diet may improve survival after surgery
A new study in mice found that several days on a restricted diet helped in coping with the stress of surgery. The research, led by Dr. James Mitchell at the Harvard School of Public Health and supported in part by the NIA and the National Institute of Diabetes and Digestive and Kidney Diseases at the NIH, points the way toward potential strategies for reducing surgical risks in people.
When blood flow to an area stops during surgery and is then restored, the returning blood supply can cause tissue damage and dangerous inflammation. This process, called ischemia reperfusion, can lead to stroke, heart attack, and other serious medical problems.
To mimic the effects of ischemia reperfusion after surgery, researchers used microvascular clamps to temporarily stop blood flow in or out of the mice’s kidneys. Mice fed a protein-free diet for 6 days to 2 weeks before surgery were found to have better kidney function and a higher survival rate than animals fed a normal diet of equivalent calories. Limiting certain essential amino acids also resulted in improved survival in mice. In addition, scientists found the effects of limiting amino acids could be mimicked by halofuginone, a drug that acts on a particular protein pathway involved in helping cells detect amino acid depletion. This result raises the possibility that similar drugs might one day be used before surgery.
Past studies have found that dietary restriction—limiting food intake without causing malnutrition—can boost the body’s resistance to the stress of ischemia reperfusion.
Reference: Peng, W., et al. Surgical Stress Resistance Induced by Single Amino Acid Deprivation Requires Gcn2 in Mice. Science Translational Medicine. 2012 Jan 25; 4(118): p.118ra11.