Posts

LCHF and kidney function

Except from MSc (Med) Physiology Dissertation (UCT), by Tamzyn Murphy (RD)

 

Safety concerns have been raised over low carbohydrate high fat (LCHF) diets’ relatively high protein content, for renal function [100]. While protein intake on LCHF diets may be higher than on conventional diets, it seldom exceeds 30 % total daily energy intake (TDEI) [10, 101]. Critics theorise that high protein intake (> 25% of TDEI or > 2 g. kg body weight (BW)-1 [102])  may chronically increase glomerular pressure and hyperfiltration, thereby damaging the kidneys [103] – particularly concerning in Type 2 Diabetes (T2D) with its high nephropathy risk. Indeed protein restriction helps preserve renal function in pre-existing kidney disease [104]. However, evidence doesn’t support the theory that high protein diets impair renal function in the absence of kidney disease [100, 102, 103, 105], even in obese individuals with T2D [106].  In fact, very low carbohydrate high fat (VLCHF) diets may improve renal function [107], as indicated by results showing reversal of diabetic nephropathy in rodents [108] and reduced creatinine concentrations in an intervention study in overweight and obese humans with and without T2D [109].

 

References

  1. Crowe, T., Safety of low‐carbohydrate diets. Obesity reviews, 2005. 6(3): p. 235-245.
  2. Adam‐Perrot, A., P. Clifton, and F. Brouns, Low‐carbohydrate diets: nutritional and physiological aspects. Obesity Reviews, 2006. 7(1): p. 49-58.
  3. Møller, G., et al., Higher Protein Intake Is Not Associated with Decreased Kidney Function in Pre-Diabetic Older Adults Following a One-Year Intervention—A Preview Sub-Study. Nutrients, 2018. 10(1): p. 54.
  4. Martin, W.F., L.E. Armstrong, and N.R. Rodriguez, Dietary protein intake and renal function. Nutrition & metabolism, 2005. 2(1): p. 25.
  5. Rhee, C.M., et al., Low‐protein diet for conservative management of chronic kidney disease: a systematic review and meta‐analysis of controlled trials. Journal of cachexia, sarcopenia and muscle, 2018. 9(2): p. 235-245.
  6. Brinkworth, G.D., et al., Renal function following long-term weight loss in individuals with abdominal obesity on a very-low-carbohydrate diet vs high-carbohydrate diet. Journal of the American Dietetic Association, 2010. 110(4): p. 633-638.
  7. Tay, J., et al., Long-term effects of a very low carbohydrate compared with a high carbohydrate diet on renal function in individuals with type 2 diabetes: a randomized trial. Medicine, 2015. 94(47).
  8. Azar, S., H. Beydoun, and M. Albadri, Benefits of ketogenic diet for management of type two diabetes: a review. J Obes Eat Disord, 2016. 2(2).
  9. Poplawski, M.M., et al., Reversal of diabetic nephropathy by a ketogenic diet. PLoS One, 2011. 6(4): p. e18604.
  10. Hussain, T.A., et al., Effect of low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes. Nutrition, 2012. 28(10): p. 1016-1021.