Our kidneys have the unique function of filtering our blood to remove toxins, waste, and excess fluid. Hormones produced in the kidneys also help regulate the production of red blood cells, maintain calcium balance, and control blood pressure. Considering all this, the health of our kidneys is very important!
It is estimated that 15% adults in the United States have chronic kidney disease (CKD).1 The two major causes of CKD are diabetes and high blood pressure. Other factors associated with increased risk of developing CKD include older age, smoking, obesity, and family history of CKD.2 Uncontrolled CKD can lead to kidney failure, also known as end-stage renal disease (ESRD). Survival with ESRD requires either a kidney transplant or dialysis.
A growing body of evidence suggests that a variety of dietary interventions can slow the progression of CKD and possibly avoid or delay ESRD.3,4 The following are dietary methods for preserving kidney function:
- Follow a low-protein diet. A low-protein diet would be defined as consuming 0.6-0.8 grams of protein per kilogram of body weight per day. For example, a 75 kg (165 lb) adult would consume 45-60 grams of protein per day.
- Make at least half of your protein plant-based. Plant-based sources of protein include legumes (e.g., lentils, black beans, edamame, chickpeas, peanuts), nuts (e.g., cashews, almonds, walnuts), seeds (e.g., chia, sunflower, hemp, flax), whole grains (e.g., brown rice, quinoa, oats, barley, buckwheat), and vegetables (e.g., broccoli, brussel sprouts, artichoke, asparagus).
- Choose whole foods. Eating whole foods will help in maintaining a balanced diet, and will increase your intake of healthful antioxidants, fiber, vitamins, minerals, and phytonutrients. This will also reduce your intake of preservatives which may be detrimental to kidney health.5
- Consume adequate amounts of dietary fiber. Fiber is a type of carbohydrate that is indigestible by humans. It serves many functions including promoting satiety, improving bowel movements, and supporting a healthy gut microbiome. Dietary fiber intake recommendations include at least 25 grams per day for adult women and at least 38 grams per day for adult men.6 Be sure to drink plenty of water throughout the day as this will help the fiber move through the gastrointestinal tract.
- Limit sodium intake. Excessive intake of sodium can increase your risk of high blood pressure. High sodium foods are commonly processed and packaged foods, such as bread, cold cuts, soda, cheese, and snack foods. Make a habit out of looking at the Nutrition Facts label to assess sodium content. As a general guideline, food servings containing 5% or less of the Daily Value (DV) are considered low in sodium, while those containing 20% or more are considered high in sodium.
References
1) Centers for Disease Control and Prevention. (2020). Chronic Kidney Disease Basics. U.S. Department of Health and Human Services. https://www.cdc.gov/kidneydisease/basics.html
2) Kazancioğlu, R. (2013). Risk factors for chronic kidney disease: an update. Kidney international supplements, 3(4), 368-371.
3) Kalantar-Zadeh, K., & Fouque, D. (2017). Nutritional management of chronic kidney disease. New England Journal of Medicine, 377(18), 1765-1776.
4) Kalantar-Zadeh, K., Joshi, S., Schlueter, R., Cooke, J. L., Brown-Tortorici, A., Donnelly, M., … & Tantisattamo, E. (2020). Plant-Dominant Low-Protein Diet for Conservative Management of Chronic Kidney Disease.
5) Cupisti, A., & Kalantar-Zadeh, K. (2013, March). Management of natural and added dietary phosphorus burden in kidney disease. In Seminars in nephrology (Vol. 33, No. 2, pp. 180-190). WB Saunders.
6) Slavin, J. L. (2008). Position of the American Dietetic Association: health implications of dietary fiber. Journal of the American Dietetic Association, 108(10), 1716-1731.
