Protein

Last update: 14 May 2020

This page is about protein, especially the persistent myths surrounding its health effects. If you have any interesting studies about this, please send them to me. My contact information can be found on the About Me page.

Safety

Contrary to common claims, protein is remarkably safe, at least on par with the other two main macronutrients. Specifically:

  • Protein doesn’t cause bone loss1,2,3,4.
  • Protein doesn’t damage the liver or kidneys5,6,7,8.
  • Protein doesn’t make you fat6,9,10,20,21,22.
  • Protein doesn’t cause inflammation11.

Ethnographic research shows that many primitive cultures eat double or triple the protein percentage of civilized modern people17, yet do not suffer any of the chronic conditions of modernity (until they eat the white man’s food18, that is). Furthermore, absent rare genetic disorders, protein’s low absorption rate largely precludes even exceptional intakes from becoming a problem at the urea cycle level19.

Requirements

While humans are able to substist on low-protein diets largely indefinitely, this is unlikely to be optimal. Recent experimental evidence has shown that previous daily requirements have been underestimated12,13,14,15,16.

References

  1. J Pediatr. 2010 Aug;157(2):252-8. doi: 10.1016/j.jpeds.2010.02.010. Epub 2010 Mar 20. Efficacy and safety of a high protein, low carbohydrate diet for weight loss in severely obese adolescents. Krebs NF1, Gao D, Gralla J, Collins JS, Johnson SL.
  2. Osteoporos Int. 2018 Sep;29(9):1933-1948. doi: 10.1007/s00198-018-4534-5. Epub 2018 May 8. Benefits and safety of dietary protein for bone health-an expert consensus paper endorsed by the European Society for Clinical and Economical Aspects of Osteopororosis, Osteoarthritis, and Musculoskeletal Diseases and by the International Osteoporosis Foundation. Rizzoli R1, Biver E2, Bonjour JP2, Coxam V3, Goltzman D4, Kanis JA5,6, Lappe J7, Rejnmark L8, Sahni S9, Weaver C10, Weiler H11, Reginster JY12.
  3. Antonio J, Ellerbroek A, Evans C, Silver T, Peacock CA. High protein consumption in trained women: bad to the bone?. J Int Soc Sports Nutr. 2018;15:6. Published 2018 Jan 31. doi:10.1186/s12970-018-0210-6
  4. Osteoporos Int. 2018 Sep;29(9):1933-1948. doi: 10.1007/s00198-018-4534-5. Epub 2018 May 8. Benefits and safety of dietary protein for bone health-an expert consensus paper endorsed by the European Society for Clinical and Economical Aspects of Osteopororosis, Osteoarthritis, and Musculoskeletal Diseases and by the International Osteoporosis Foundation. Rizzoli R1, Biver E2, Bonjour JP2, Coxam V3, Goltzman D4, Kanis JA5,6, Lappe J7, Rejnmark L8, Sahni S9, Weaver C10, Weiler H11, Reginster JY12.
  5. J Nutr. 2018 Nov 1;148(11):1760-1775. doi: 10.1093/jn/nxy197. Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis. Devries MC1, Sithamparapillai A2, Brimble KS3, Banfield L4, Morton RW2, Phillips SM2.
  6. Antonio J, Ellerbroek A, Silver T, et al. A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males. J Nutr Metab. 2016;2016:9104792. doi:10.1155/2016/9104792
  7. Martin WF, Armstrong LE, Rodriguez NR. Dietary protein intake and renal function. Nutr Metab (Lond). 2005;2:25. Published 2005 Sep 20. doi:10.1186/1743-7075-2-25
  8. Int J Sport Nutr Exerc Metab. 2000 Mar;10(1):28-38. Do regular high protein diets have potential health risks on kidney function in athletes? Poortmans JR1, Dellalieux O.
  9. J Int Soc Sports Nutr. 2014 May 12;11:19. doi: 10.1186/1550-2783-11-19. eCollection 2014. The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. Antonio J1, Peacock CA1, Ellerbroek A1, Fromhoff B1, Silver T1.
  10. Am J Clin Nutr. 2005 Jul;82(1):41-8. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Weigle DS1, Breen PA, Matthys CC, Callahan HS, Meeuws KE, Burden VR, Purnell JQ.
  11. Br J Nutr. 2015 Dec 14;114(11):1819-28. doi: 10.1017/S0007114515003530. Epub 2015 Sep 24. Dietary proteins improve endothelial function under fasting conditions but not in the postprandial state, with no effects on markers of low-grade inflammation. Teunissen-Beekman KF1, Dopheide J1, Geleijnse JM1, Bakker SJ1, Brink EJ1, de Leeuw PW2, Schalkwijk CG2, van Baak MA1.
  12. Curr Opin Clin Nutr Metab Care. 2010 Jan;13(1):52-7. doi: 10.1097/MCO.0b013e328332f9b7. Evidence that protein requirements have been significantly underestimated. Elango R1, Humayun MA, Ball RO, Pencharz PB.
  13. J Nutr. 2016 Mar 9. pii: jn225631. [Epub ahead of print] Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement. Rafii M1, Chapman K1, Elango R2, Campbell WW3, Ball RO4, Pencharz PB5, Courtney-Martin G6.
  14. J Nutr. 2015 Jan;145(1):18-24. doi: 10.3945/jn.114.197517. Epub 2014 Oct 15. Dietary protein requirement of female adults >65 years determined by the indicator amino acid oxidation technique is higher than current recommendations. Rafii M1, Chapman K1, Owens J1, Elango R2, Campbell WW3, Ball RO4, Pencharz PB5, Courtney-Martin G6.
  15. J Gerontol A Biol Sci Med Sci. 2001 Jun;56(6):M373-80. The recommended dietary allowance for protein may not be adequate for older people to maintain skeletal muscle. Campbell WW1, Trappe TA, Wolfe RR, Evans WJ.
  16. Traylor DA, Gorissen SHM, Phillips SM. Perspective: Protein Requirements and Optimal Intakes in Aging: Are We Ready to Recommend More Than the Recommended Daily Allowance?. Adv Nutr. 2018;9(3):171–182. doi:10.1093/advances/nmy003
  17. Loren Cordain, Janette Brand Miller, S Boyd Eaton, Neil Mann, Susanne HA Holt, John D Speth, Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets, The American Journal of Clinical Nutrition, Volume 71, Issue 3, March 2000, Pages 682–692, https://doi.org/10.1093/ajcn/71.3.682
  18. Weston A. Price, Nutrition and Physical Degeneration.
  19. Int J Sport Nutr Exerc Metab. 2006 Apr;16(2):129-52. A review of issues of dietary protein intake in humans. Bilsborough S1, Mann N.
  20. Antonio, J., Ellerbroek, A., Silver, T. et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women – a follow-up investigation. J Int Soc Sports Nutr 12, 39 (2015). https://doi.org/10.1186/s12970-015-0100-0
  21. Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. J Int Soc Sports Nutr. 2014;11:20. Published 2014 May 12. doi:10.1186/1550-2783-11-20
  22. Antonio, Jose & Ellerbroek, Anya. (2018). Case reports on well-trained bodybuilders: Two years on a high protein diet. Journal of Exercise Physiology Online. 21. 14-24.