Kidney function generally decreases as people age, so that from young adulthood to old age, perhaps half of the original kidney function is lost. There is some argument about whether decreasing renal function with age is “normal” or pathologic. In the Baltimore Longitudinal Study on Aging, a cohort of men followed for several decades, about one-third of subjects did not have a decline in renal function.1

Thus, although “age” is not a specific determinant of renal function, diet can contribute to common kidney diseases in many ways. In westernized countries, the most common reasons for having advanced chronic kidney disease or needing dialysis are the traditional risk factors, diabetes, and hypertension.2

Typical American diets are often high in calories, sugar, and salt, which can promote obesity, diabetes, and high blood pressure. All of these factors promote a decline in renal function, as well as damage to other organ systems, such as the heart, brain, and peripheral blood vessels. For these people, the underlying pathology is damage to the blood vessels, leading to progressive ischemic kidney disease.3 Being on dialysis does not stop the underlying damage to the rest of the body so that death from cardiovascular disease within a few years of starting dialysis is common.4,5

Paleolithic-type foods will vary depending on the ecology of the biosystem but typically were mostly composed of meat or fish, fruits, vegetables, roots, insects, and nuts. The salt content of natural foods is extremely low.6 Intake of whole fruit, which contains fructose as well as fiber, has been shown not to increase fructosamine or glucose levels, suggesting that the effects of carbohydrates in the body depend on the source of the carbohydrate.7 Studies using Paleolithic-type diets have reported decreases in weight, fasting blood glucose and blood pressure.8,9

Western diets also contain a number of non-traditional risk factors for renal disease. These are classified as uremic toxins, substances that accumulate in renal failure and whose accumulation also results in further renal failure. These include high phosphate intake – often in the form of sodas, dairy products, and legumes, high diet acid content – due to low fruits and vegetable intake, and high uric acid intake – mainly due to high fructose corn syrup.10

High uric acid intake and high phosphate intake can lead to an increased incidence of renal stones.8 Fruits and vegetables contain bicarbonate precursors, in the form of organic anions like citrate and malate, which buffer the acid load coming from the rest of the diet.11 Recent data suggest that buffering the tissue acid loads slow progression of kidney disease.12 Phosphate is mainly regulated by FGF23 and klotho is a co-factor for FGF23. The higher the diet phosphate intake, the greater the amount of FGF23 produced, which leads to lower klotho levels.11 Klotho has been identified as an antiaging factor.12 So, higher phosphate intake may potentially lead not just to the progression of renal disease but also to faster aging due to higher FGF-23 and lower klotho levels13,14.

Paleo-type diets, in comparison, which generally have high plant food contents, are usually higher in potassium and lower in sodium than even “healthy” diets, such as the Mediterranean or DASH-like diets.15 Diets high in plant foods and low in salt would also be low acid diets.16 Eliminating high fructose corn syrup, would not only lower sugar intake but lower uric acid production. And, although all foods contain phosphates, eliminating foods with high or added phosphates such as dairy products, legumes, and sodas, will limit dietary phosphate intake.6

In summary, Paleo-type diets limit damage to the blood vessels in the kidneys and other organ systems by limiting salt and sugar, decrease kidney stone production by lowering intake of dietary uremic toxins, lower diet acid loads, and potentially lower FGF23 and higher klotho levels. All of these effects together should lead to improvements in the function of the kidneys as well as the rest of the body.

Read the full Evolutionary Mismatch series:

  1. Introduction: Evolutionary Mismatch and What To Do About It by David Sloan Wilson
  2. Functional Frivolity: The Evolution and Development of the Human Brain Through Play by Aaron Blaisdell
  3. A Mother’s Mismatch: Why Cancer Has Deep Evolutionary Roots by Amy M. Boddy
  4. It’s Time To See the Light (Another Example of Evolutionary Mismatch) by Dan Pardi
  5. Generating Testable Hypotheses of Evolutionary Mismatch by Sudhindra Rao
  6. (Mis-) Communication in Medicine: A Preventive Way for Doctors to Preserve Effective Communication in Technologically-Evolved Healthcare Environments by Brent C. Pottenger
  7. The Darwinian Causes of Mental Illness by Eirik Garnas
  8. Is Cancer a Disease of Civilization? by Athena Aktipis
  9. The Potential Evolutionary Mismatches of Germicidal Ambient Lighting by Marcel Harmon
  10. Do We Sleep Better Than Our Ancestors? How Natural Selection and Modern Life Have Shaped Human Sleep by Charles Nunn and David Samson
  11. The Future of the Ancestral Health Movement by Hamilton M. Stapell
  12. Humans: Smart Enough to Create Processed Foods, Daft Enough to Eat Them by Ian Spreadbury
  13. Mismatch Between Our Biologically Evolved Educative Instincts and Culturally Evolved Schools by Peter Gray
  14. How to Eliminate Going to the Dentist by John Sorrentino
  15. Public Health and Evolutionary Mismatch: The Tragedy of Unnecessary Suffering and Death by George Diggs
  16. Is Shame a Bug or a Feature? An Applied Evolutionary Approach by Nando Pelusi
  17. The “Benefits,” Risks, and Costs of Routine Infant Circumcision by Stephanie Welch
  18. An Evolutionary Perspective on the Real Problem with Increased Screen Time by Glenn Geher
  19. Did Paleolithic People Suffer From Kidney Disease? by Lynda Frassetto
  20. The Physical Activity Mismatch: Can Evolutionary Perspectives Inform Exercise Recommendations? by James Steele

References

[1]. Lindeman RD, Tobin J, Shock NW. Longitudinal studies on the rate of decline in renal function with age. J Am Geriatr Soc. 33(4):278-85, 1985.

[2]. http://www.globalsherpa.org/urban-design-health-obesity

[3]. NHANES 1999–2006 participants age 20 & older. USRDS 2010; https://www.cdc.gov/nchs/data-linkage/esrd.htm

[4]. Green D1, Roberts PR, New DI, Kalra PA. Sudden cardiac death in hemodialysis patients: an in-depth review. Am J Kidney Dis. 57(6):921-9, 2011. doi: 10.1053/j.ajkd.2011.02.376.

[5]. Sniderman AD, Solhpour A, Alam A, Williams K, Sloand JA. Cardiovascular death in dialysis patients: lessons we can learn from AURORA. Clin J Am Soc Nephrol. 5(2):335-40, 2010. doi: 10.2215/CJN.06300909.

[6]. https://ndb.nal.usda.gov/ndb/search/list

[7]. Masharani U, Sherchan P, Schloetter M, Stratford S, Xiao A, Sebastian A, Nolte Kennedy M, Frassetto L. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. Eur J Clin Nutr. 69(8):944-8, 2015. doi: 10.1038/ejcn.2015.39.

[8]. Lindeberg S, Jönsson T, Granfeldt Y, Borgstrand E, Soffman J, Sjöström K, Ahrén B. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia. Sep;50(9):1795-1807, 2008.

[9]. Manheimer EW, van Zuuren EJ, Fedorowicz Z, Pijl H. Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis. Am J Clin Nutr. Oct;102(4):922-32, 2015.

[10]. Taylor EN, Curhan GC. Fructose consumption and the risk of kidney stones. Kidney Int’l 73:207-12, 2008.

[11]. Lennon EJ, Lemann J Jr, Litzow JR. The effects of diet and stool composition on the net external acid balance of normal subjects. J Clin Invest. 45(10):1601-7, 1966.

[12]. Goraya N, Simoni J, Jo CH, Wesson DE. Treatment of metabolic acidosis in patients with stage 3 chronic kidney disease with fruits and vegetables or oral bicarbonate reduces urine angiotensinogen and preserves glomerular filtration rate. Kidney Int. 86(5):1031-8, 2014. doi: 10.1038/ki.2014.83

[13]. Kuro-o M. Klotho and the aging process. Korean J Intern Med 26(2); 113-22, 2011.

[14]. John GB, Cheng CY, Kuro-o M. Role of Klotho in aging, phosphate metabolism, and CKD. Am J Kidney Dis. 58(1):127-34, 2011.

[15]. Sacks FM, Svetkey LP, Vollmer WM et al. DASH-Sodium Collaborative Research Group. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. NEJM 344(1):3, 2001.

[16]. Frassetto LA, Morris RC Jr, Sebastian A. Dietary sodium chloride intake independently predicts the degree of hyperchloremic metabolic acidosis in healthy humans consuming a net acid-producing diet. Am J Physiol Renal Physiol. 293(2):F521-5, 2007.