Protein and caloric restriction
Protein and caloric restriction has been studied in 2 papers since 2020: 2 trials in people. The newest paper, Nov 11, 2021: “Short-Term Pre-Operative Protein Caloric Restriction in Elective Vascular Surgery Patients: A Randomized Clinical Trial”.
2 papers study it10 findingsUpdated
“From postoperative day 2 up until month 1, kidney function of donors was significantly better in the PCR-group.”
None of its findings points the other way.
- 2 independent labs in 2 countries
- Funders: National Institute on Aging and 3 more
- Human trial2
Studies in people
2 studies gave protein and caloric restriction to people and measured what changed.
down: Decreases body weight
up: Improves insulin sensitivity
no change: Has no effect on cardiovascular complicationsHR 1.65, 95% CI 0.17–16.5
Randomized trial19 peoplefour days
Patients scheduled to undergo an elective open vascular surgery procedure
Nutrients, Nov 11, 2021
down: Decreases slow graft function
down: Decreases acute rejection
Randomized trial35 peoplefive days preoperatively
In living kidney donors, postoperative day 2 to month 1
Aging, Jul 11, 2020
What did studies of Protein and caloric restriction find?
9Studies of Protein and caloric restriction measured 9 outcomes; the most studied are cardiovascular complications (1 study), leukocyte populations (1) and insulin sensitivity (1).
Cardiovascular complications
no changein humans1HR 1.65
1 study
Cardiovascular complications
no changein humans1HR 1.65
Protein and caloric restriction showed no clear effect on cardiovascular complications in humans (HR 1.65, 95% CI 0.17–16.5).
“No adverse events differed significantly between experimental groups in univariable Cox regression.”
Human trialn = 19
Nutrients
Protein and caloric restriction showed no clear effect on cardiovascular complications in humans (elective vascular surgery; compared with regular ad-libitum diet).
“Between diet groups, there were similar rates of re-intervention, wound infection, and cardiovascular complications.”
Human trialelective vascular surgery; compared with regular ad-libitum diet30% calorie, 70% protein restrictionone-year postoperative follow-up
Nutrients
Leukocyte populations
no changein humans1
1 study
Leukocyte populations
no changein humans1
Protein and caloric restriction showed no clear effect on leukocyte populations in humans.
“None of the interrogated cell populations (granulocytes, monocyte subtypes, T-cell subsets, NK cells, dendritic cells, and B cells) showed any differences between diet groups and before/after surgery.”
Human trialn = 19
Nutrients
Insulin sensitivity
upin humans1
1 study
Insulin sensitivity
upin humans1
Protein and caloric restriction improves insulin sensitivity in humans (pre-operative).
“However, we did see a trend towards increased insulin sensitivity as a result of the PCR diet at the pre-operative timepoint as measured by insulin levels ( E).”
Human trialpre-operative
Nutrients
Body weight
downin humans1
1 study
Body weight
downin humans1
Protein and caloric restriction decreases body weight in humans (pre-operative).
“The PCR group appeared to have lost weight at the pre-operative visit ( A).”
Human trialpre-operative
Nutrients
stress-resistance pathways
upin humans1
1 study
stress-resistance pathways
upin humans1
Protein and caloric restriction activates stress-resistance pathways in humans.
“activated stress-resistance signaling”
Human trialkidney30% calorie and 80% protein reductionfive days preoperatively
Aging
Immune response
downin humans1
1 study
Immune response
downin humans1
Protein and caloric restriction inhibits immune response in humans.
“PCR inhibited cellular immune response pathways”
Human trialkidney30% calorie and 80% protein reductionfive days preoperatively
Aging
Acute rejection
downin humans1
1 study
Acute rejection
downin humans1
Protein and caloric restriction decreases acute rejection in recipients of PCR-treated donors.
“lower incidence of slow graft function and acute rejection”
Human trialin recipients of PCR-treated donorskidney30% calorie and 80% protein reductionfive days preoperatively
Aging
Slow graft function
downin humans1
1 study
Slow graft function
downin humans1
Protein and caloric restriction decreases slow graft function in recipients of PCR-treated donors.
“lower incidence of slow graft function and acute rejection”
Human trialin recipients of PCR-treated donorskidney30% calorie and 80% protein reductionfive days preoperatively
Aging
Kidney function
upin humans1
1 study
Kidney function
upin humans1
Protein and caloric restriction improves kidney function in living kidney donors, postoperative day 2 to month 1.
“From postoperative day 2 up until month 1, kidney function of donors was significantly better in the PCR-group.”
Human trialin living kidney donors, postoperative day 2 to month 1kidney30% calorie and 80% protein reductionfive days preoperativelyn = 35
Aging