Teaching Dialysis Patients About Phosphorus

[okarol]

Teaching Dialysis Patients About Phosphorus
Alison Steiber, PhD, RD, LD
May 11 2010

Elevated serum phosphorus is a strong independent risk factor for mortality in maintenance hemodialysis (MHD) patients, so controlling serum phosphorus levels is a priority (Kidney Int. 2006;70:771-780). Clinicians attempt to control patients' serum phosphorus by restricting their dietary phosphorus intake or by prescribing phosphate binders. One of the challenges with respect to dietary restrictions is that high-protein foods contain high levels of phosphorus. Therefore, a low phosphorus diet means limiting animal and plant protein sources such as beef, cheese, legumes, and milk. While these foods are high in phosphorus, they are also excellent sources of protein; for example one eight-ounce glass of whole milk provides 8 g of protein, 150 kilocalories, and approximately 222 mg of phosphorus. This glass of milk would provide approximately 25% of patients' phosphorus allowance and 10% of their protein requirements per day. Maximizing dietary protein intake in MHD patients is essential to preventing malnutrition and protein-energy wasting, both of which are also independent risk factors for mortality in MHD patients.

Optimal diet

Shinaberger et al (Am J Clin Nutr. 2008;88:1511-1518) suggests that the optimal diet for MHD patients is both high in protein and low in phosphorus. In this study, death risk was compared between increasing and decreasing dietary intakes of protein and phosphorus in 30,075 MHD patients over six months. Normalized protein nitrogen appearance (nPNA) was used as a surrogate marker for dietary protein intake. Results of this analysis were that serum phosphorus does have an almost linear association with nPNA; death rates increase both with a declining nPNA and increasing serum phosphorus; patients with the lowest nPNA and highest serum phorsphorus had the highest mortality, and, conversely, those with the highest nPNA and lowest serum phosphorus had the lowest mortality. So what is a clinician to do?

Part of the answer may be found in the American food supply. Processed foods contain varying amounts of phosphorus as an additive, which may contribute significantly to our overall phosphorus intake. Phosphorus is used to increase shelf life, improve or enhance flavor, and to prevent food products from dehydrating. The FDA does not require food manufacturers to put phosphorus content on food product labels. Therefore, it is extremely difficult for a patient to know how much phosphorus foods contain.

Fast food

In a study published in 2007 (J Ren Nutr. 2007;17:264-268), researchers found that MHD patients between 18 and 44 years of age consumed an average of 2.1 fast food meals per week. In a separate study (J Ren Nutr. 2008;18:466-470), the same researchers analyzed foods offered by fast food chains in the greater Cleveland area. The foods were judged by criteria on sodium, potassium, naturally occurring phosphorus, and the presence of phosphate additives. Based on those criteria, only 16% of the foods were acceptable for a renal patient.

Phosphate additives

To combat the problem of phosphate additives patients can be taught to identify phosphate additives on food labels and to avoid foods containing these additives. This was done with positive results by Sullivan et al (JAMA. 2009;301:629-635). Patients with baseline phosphorus concentrations greater than 5.5 mg/dL were enrolled and randomized to receive either standard of care or intensive phosphorus additive education and tools (such as a pocket sized magnifier for label reading) to assist in phosphorus identification. At baseline, the serum phosphorus concentrations were similar between the intervention and control groups (7.2 vs. 7.1 mg/dL, respectively). Three months after receiving baseline intervention, the serum phosphorus of the treatment group had decreased by 1.0 mg/dL compared with 0.4 mg/dL in the control group. The findings show that educating patients on phosphorus additives can effectively reduce serum phosphorus values over our current standard of care. This study did not analyze serum albumin at three months, so it is not possible to determine whether visceral protein status was impacted by these changes. Kalantar-Zadeh et al (Clin J Am Soc Nephrol. 2010; published online ahead of print) suggests using a dietary phosphorus-to-protein (mg/g) ratio for dietary prescriptions. This ratio has advantages, such as better comparability between food items. A major limitation, however, is that we do not know the phosphorus content of many foods available to our patients. Thus, the ratio often cannot be accurately calculated.

Until it is possible to know precisely how much phosphorus is in processed and fast foods, clinicians need to take extra time to educate their patients on phosphate additives, their potential for harm, and on how to identify these additives on food labels. Meanwhile, consumption of high protein foods, which naturally contain greater amounts of phosphorus, needs to be carefully monitored to maintain a balance between optimal visceral protein status and serum phosphorus values.

http://www.renalandurologynews.com/teaching-dialysis-patients-about-phosphorus/article/169904/

[Bajanne]

I have been worried about my phosphorus level (again).  I am trying to be very compliant in taking my binders.  I am doing a little phosphorus challenge sent out by Davita.  It is a bit childish, but it helping to keep phosphorus before my eyes!

[Sunny]

What are the names of phophorus additives so I can learn to identify them?

[okarol]

Hidden phosphorus in your diet and how to control it

Written by Lisa Gutekunst, DaVita MSEd, RD, CSR, CDN

As someone with chronic kidney disease (CKD), you faithfully take your phosphate binders as directed by your doctor, no longer drink milk, add cheese to your burgers or indulge in chocolate or chili. But still you see your phosphorus levels higher than you or your health care team wants them. Frustrated, you wonder what you are doing wrong.

The reason your phosphorus level is high may be due to hidden sources of dietary phosphorus.
Hidden phosphorus and the food industry
Hidden phosphorus in your diet and how to control it
The food industry is adding more phosphate additives to foods that are traditionally considered low phosphorus foods. The following are a few foods and beverages that now contain hidden phosphorus:

    * Flavored waters
    * Iced teas
    * Cola beverages
    * Enhanced meat and chicken products
    * Breakfast (cereal) bars
    * Nondairy creamers
    * Bottled coffee beverages
    * Hawaiian Punch®
    * Sunny Delight®
    * Code Red Mountain Dew®
    * Hire’s® Root Beer
    * Hormel® Always Tender products

The number of products containing these additives grows weekly as marketers bring new products to their shelves. This makes it virtually impossible for dietitians and those with chronic kidney disease to know what is “safe” and what should be limited.

The food industry is adding additional dietary phosphorus to meet the demands of the American public for wholesome foods. We are now a “grab and go” society, looking for quick, healthy snacks and meals that take very little time to prepare.

Phosphates are added to foods for a variety of reasons. They are considered a Jack-of-all-trades because of their versatility and their low cost to the manufacturer. Phosphorus additives can be used to make foods creamier, allow foods that would not normally melt to melt, maintain the juiciness of meat and prevent beverages from separating into individual ingredients. They can also add or reduce acidity, accompany added nutrients (as in calcium fortification), and “brand” a product by adding unique flavors. Phosphate additives also make food last longer. For example, phosphate salts are added to meats in order to reduce chances of rancidness – the phosphate additive extends the shelf life of the enhanced meat.
Locating hidden phosphorus in your diet

Locating hidden sources of phosphorus in your diet requires patience, diligence and a lot of label reading. However, it is worth the effort to help you reduce the amount of phosphorus in your diet. Table 1 lists the most common phosphate additives used today. Though the nutrition label does not usually include the phosphorus content of a product, looking for these ingredients on food packages will help you identify foods that should either be eliminated or avoided.

Table 1: Other words that also mean Phosphate Additives

Phosphoric Acid
   

Sodium Polyphosphate

Pyrophosphate
   

Sodium Tripolyphosphate

Polyphosphate
   

Tricalcium Phosphate

Hexametaphosphate
   

Trisodium Phosphate

Dicalcium Phosphate
   

Sodium Phosphate

Monocalcium Phosphate
   

Tetrasodium Phosphate

Aluminum Phosphate
   

 
How to avoid hidden phosphorus in foods: your dietitian can help

Where you shop can make a big difference in the number of products containing hidden phosphorus. Because phosphate additives are inexpensive, budget markets and multipurpose mega centers tend to carry a lot of these products.

If you are on a budget, your renal dietitian can help provide options when it comes to purchasing food for your kidney diet. Consider talking to your renal dietitian about your options when it comes to buying food for your special diet. Dietitians are dedicated to working with you to meet your nutritional goals.

While we are aware there are challenges with the renal diet, you can take control of your diet and eliminate sources of hidden dietary phosphorus with a few strategies.
Strategies to help control hidden phosphorus in your diet

First, look for alternative foods and beverages that are lower in phosphorus. For example, many plastic bottled orange-flavored and fruit punch flavored beverages contain phosphorus. However, most refrigerated orange drink and fruit punches do not have added phosphorus. Many premixed punches contain phosphorus, but a popular unsweetened mix does not. You just have to add sugar and water. And, the unsweetened powder is less expensive than the premixed products. Regular, old-fashioned oats, though a high phosphorus food that should be limited, contains far less phosphorus and sodium than the instant oatmeal. You just need to spend a few more minutes cooking.

Second, let your dietitian know when you find a food or beverage that does not contain added phosphorus so he or she can pass along the information to other chronic kidney disease patients. Your dietitian will appreciate your help in keeping everyone up to date on what’s new in the market. The more products you find that you and others on a low-phosphorus diet can have, the more dietitians can add to the food choices in your CKD diet.

Finally, limit phosphorus where you can. You may need to purchase meat products enhanced with phosphorus, but you can cut out additional phosphorus at your meal by using fresh rice instead of instant rice, and using fresh or frozen vegetables that do not contain additional sauce.
Summary

Hidden phosphorus in the diet may continue to be a problem for those with chronic kidney disease. With patience and determination, you and your dietitian can work through this challenge so you can avoid this pitfall and keep your phosphorus level in an ideal range.

http://www.davita.com/diet-and-nutrition/diet-basics/a/2335