Think about your favorite food. It could be a deliciously ripe raspberry fresh off the vine; maybe it’s a favorite family dish that’s made with love every
holiday season, or a recipe you have created on your own, tweaking it carefully throughout the years so the flavors come together perfectly.
Now imagine having that beautiful, mouthwatering food in front of you, taking a bite, and tasting nothing. What a disappointment.
About 35% of people with end stage renal disease (ESRD) experience this disappointment on a regular basis. Dysgeusia or altered taste perception
can present in different ways depending on the underlying cause:

  • High urea levels lead to bitter tastes
  • High levels of potassium lead to a metallic taste
  • High sodium levels lead to a raised threshold to perceive salty tastes
  • Zinc deficiency blunts taste

Zinc deficiency is common in ESRD with levels being lowest in patients on hemodialysis (HD). The deficiency is caused by a combination of poor
dietary intake, malabsorption in the GI tract, and significant loss of zinc during the dialysis process, leaving many patients at risk of reduced
taste perception.
While it might be easy to overlook, taste changes like those associated with zinc deficiency, can have serious health ramifications.
Stemming from the loss of taste, people often experience a significantly diminished appreciation and enjoyment of eating. This in turn can lead
to food avoidance, malnutrition, depression, anxiety, and difficulty adhering to disease-specific diet recommendations, like salt restriction,
in an attempt to make food more palatable.
As clinicians, we can help patients reconnect with their enjoyment of food and perhaps even bring back their taste perception. To know if zinc is the culprit, deficiency can be assessed by reviewing dietary intake and looking for other signs and symptoms including:

  • Alopecia
  • Diarrhea
  • Loss of appetite/anorexia
  • Impaired wound healing
  • Vesicular or pustular rash

To improve zinc levels, zinc-rich foods could be encouraged, this includes foods like oysters, beef, turkey breast, pumpkin seeds, oatmeal, and lentils.
If food is not the path forward, some small studies have found that zinc supplementation can enhance taste acuity and recognition thresholds.
While KDOQI Nutrition Guidelines discourages routine supplementation of zinc, it can be considered in patients who are showing signs or symptoms
of zinc deficiency. The recommendation is supplementation of 2-3mg/kg/day for 1-2 weeks, never exceeding the upper limit of 40mg/day.
Given the small studies and mixed results, increasing zinc may not be a successful approach for everyone. In this case, it can help the patient to focus
on other strategies to make food more appealing which can include:

  • Preparing foods with a variety of colors and textures
  • Using aromatic herbs and hot spices, as tolerated, to add more flavor without the use of salt or sugar
  • Experiment with kidney-friendly condiments like:
    • Vinegar
    • Lemon
    • Low sodium ketchup
    • Fresh horseradish
  • Avoid combination dishes; foods such as casseroles can actually dilute flavor and taste

When you have identified a patient with taste dysfunction it is important to continue to monitor them for insufficient oral intake or malnutrition
and intervene early. If you have a patient struggling to meet oral nutrition needs for any reason, they may be a candidate for IDPN for HD or IPN for PD
to boost nutrient availability. For more resources on micronutrient deficiencies and malnutrition assessment, visit the clinician portal at pcacorp.com.