HealthCert Blog

Did you know that individualised nutrition can help slow the progression of chronic kidney disease (CKD) and help preserve renal function (1)? However, only 10 per cent of people with CKD see a dietitian before reaching end-stage renal failure, despite the National Kidney Foundation recommending medical nutrition therapy as a cornerstone of treatment (2).

While early detection and treatment is a priority for primary care physicians, a referral to a dietitian can make a huge difference to a patient’s quality of life. Here are some important nutritional considerations to keep in mind.

Protein

Protein is essential for building muscle, repairing tissue, and fighting infection. Those with declining kidney function may need to be careful about their protein intake to prevent protein by-products from collecting in the blood.

As the kidneys are responsible for removing this waste, eating more protein than is needed may make the kidneys work harder, which can hasten decline over time (3). As protein needs vary depending on factors such as CKD stage, gender, and muscle mass, it is important that patients work with a nephrologist and a renal dietitian to plan the amount and type of protein sources in their diet.

Sodium and salt

Limiting dietary salt intake in CKD is important as the kidneys lose the ability to remove minerals like sodium effectively from the blood. Eating too much salt can alter the balance of sodium and water in the body, resulting in high blood pressure and other problems such as swelling of the ankles and fingers, puffy eyes, and excessive thirst (4). A high salt intake has also been shown to increase the amount of protein in the blood, which is another major risk factor for a decline in kidney function (5).

The National Kidney Foundation recommend individuals with early CKD to keep sodium consumption to less than 2,300 a day (about 1 teaspoon of salt). Patients can use simple strategies to shop, plan, and prepare meals with less sodium, like using spices and herbs in cooking in place of salt, choosing products that are labelled reduced or low sodium, and requesting for sauces on the side in restaurants.

Potassium and phosphorous

While keeping track of protein and sodium intake is important even in the early stages of CKD, potassium and phosphorous are minerals that don’t become an issue until later. If the kidneys cannot remove excess potassium and phosphorous, these will build up to high levels in the blood, leading to serious complications such as irregular heartbeat, muscle weakness, bone disorders, and numbness (4, 6).

As potassium and phosphorous are found in many fruits and vegetables, it is important that patients seek personalised dietary advice on the foods that can or cannot be included in their diet rather than avoid these altogether. Primary care physicians may also prescribe phosphate binders for patients to take with meals and snacks, which help control the amount of phosphorous that is absorbed.

Learn more about dietary strategies to manage chronic kidney disease in the online Professional Diploma Program in Medical Nutrition.

Lynette Law, Provisional Accredited Practising Dietitian

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References

1. Patients with Chronic Kidney Disease. Nutrients. 2017;9(5):495.
2. Kramer H, Jimenez EY, Brommage D, Vassalotti J, Montgomery E, Steiber A, et al. Medical Nutrition Therapy for Patients with Non–Dialysis-Dependent Chronic Kidney Disease: Barriers and Solutions. Journal of the Academy of Nutrition and Dietetics. 2018;118(10):1958-65.
3. Kramer H. Diet and Chronic Kidney Disease. Advances in Nutrition. 2019;10(Supplement_4):S367-S79.
4. Ikizler TA, Burrowes JD, Byham-Gray LD, Campbell KL, Carrero J-J, Chan W, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. American Journal of Kidney Diseases. 2020;76(3):S1-S107.
5. Borrelli S, Provenzano M, Gagliardi I, Michael A, Liberti ME, De Nicola L, et al. Sodium Intake and Chronic Kidney Disease. Int J Mol Sci. 2020;21(13):4744.
6. Chang AR, Anderson C. Dietary Phosphorus Intake and the Kidney. Annu Rev Nutr. 2017;37:321-46.