Kidney Diet Tips

COVID-19 UPDATES

The health and safety of our patients and teammates is our top priority. We are keeping a close eye on this situation and reinforcing the extensive infection control practices already in place to protect them. Click here to find videos and additional resources.

Using a Pressure Cooker to Reduce Phosphorus

Pressure cookers have been around for some time, but many people do not use this fantastic appliance. There may be a good reason for those in the renal community to rethink pressure cooking. A study published in 2015 “The Effect of Various Boiling Conditions on Reduction of Phosphorus and Protein in Meat” showed that phosphorus content of beef could be reduced by up to 72% after boiling in a pressure cooker for only 30 minutes. It is well-known in the dialysis community that high protein intake is a must. However, high-protein foods such as meat and poultry also have a high phosphorus content, a nutrient to be avoided in excess. The results of the 2015 study showcase a way for dialysis patients to be able to eat high-protein foods while consuming less phosphorus. Let’s take a closer look at the pressure cooker…

What is a Pressure Cooker?

Simply stated by consumerreports.org: “a pressure cooker is a metal pot with a tight-fitting lid that seals.” There are two main types: stovetop and electric. Both have their pros and cons, so one cannot be solidly defined as “better” than the other.

Stovetop pressure cookers are classic. They tend to cook faster than their electric counterparts but require more attention. That is, you cannot just set the timer and walk away from the stove. You must nurse your cooking at certain intervals. Another turn-off from the stovetop version is their noisiness, especially when releasing pressure.

Electric pressure cookers, while slower than traditional stovetop ones, are user-friendly. You can press a button, turn around, and come back when the timer goes off. Additionally, newer versions are usually multipurpose. They combine a “pressure cooker, slow cooker, rice cooker and yogurt maker in one handy unit” (nytimes.com). A downside for the electric cookers is that they tend to require a more labor-intensive clean-up than their stovetop counterparts.

Pressure Cooker Quick History 101

The original pressure cooker was invented in 1679 and was called a “steam digestor.” However, pressure cookers became a household name in the late 1930s. That’s when Presto unveiled its modern version of the appliance. Unfortunately, as they grew in popularity the original pressure cookers eventually became well-known for episodes of exploding. There were even reports of split pea soup sticking to the ceiling. Since then, newer versions have consistently introduced more and more safety features.

Pressure cookers regained public momentum in the United States and Canada in 2009 and sales have been rising since 2010 (from $42 million to $56 million in 2017).

What to Cook in a Pressure Cooker?

Meat! Now that we know pressure cooking reduces the phosphorus levels in meat without sacrificing protein content, take advantage of this opportunity. Slice your meats thin and boil them in the pressure cooker for about 30 minutes before moving them to your preferred cooking method such as roasting or grilling.

What else is a pressure cooker good for? Hard-boiled eggs! Talk about easy-to-peel… Additionally, beans and cheesecake are two other great, unexpected options that can be easily prepared in a pressure cooker. Be warned, though, that pressure cookers may not always be vegetable-friendly, as the high heat and pressure can cause them to become wilted and dull. Therefore, consider cooking vegetables, particularly leafy greens, using a different method such as sautéing.

How Does a Pressure Cooker Work?

As the name suggests, the methodology behind pressure cooking is related to…pressure! Steam builds up inside of the pressure cooker once the lid is latched tight. In turn, this raises the boiling point of water. This higher boiling point makes the food cook faster. If done properly, pressure cooking can reduce total cooking time by anywhere from 60 to 75%.

Another positive note about using a pressure cooker is the decreased need for cooking liquids. The entirety of the cooking process is sealed within the confines of the pressure cooker. The liquids used for cooking have nowhere to evaporate, which is what occurs during any other cooking processes. Therefore, less liquid is needed because none of it is being lost during cooking.

Selecting a Pressure Cooker

There are plenty of options on the market for pressure cookers. The experts tell us to look for one that is thick, wide and deep, as well as made of stainless steel rather than aluminum. Select a pressure cooker that reaches 15 psi. This will ensure the most heat, the most pressure, and less cooking time. Additionally, a higher psi will contribute to reduction in overall energy usage (and therefore energy costs). Lower psi values make overall cooking times longer. Fastcooking.ca mentions, “Many low-cost pressure cookers do not list their operating pressure so are likely to be very low.” Keep all these details in mind when comparing models.

Some of the top-rated models include the following: Fagor Lux Multi-Cooker, Instant Pot Programmable Electric Pressure Cooker, Breville the Fast Slow Pro, Gourmia Multi-Mode Smartpot 8-in-1 Programmable Pressure Cooker, and IMUSA Electric Pressure Cooker. Prices range from under $100 to over $200, depending on the design.

References 

Ando, Sakiko, et al. The Effect of Various Boiling Conditions on Reduction of Phosphorus and Protein in Meat Journal of Renal Nutrition Vol 25, No 6, November 2015: pp 504-509.

Clark, M. (2017, January 31). Why Do Cooks Love the Instant Pot? I Bought One to Find Out. Retrieved from https://www.nytimes.com/2017/01/31/dining/instant-pot-electric-pressure-cooker-recipes.html.

Cook’s Illustrated. (2013, January). Pressure Cookers. Retrieved from https://www.cooksillustrated.com/videos/2379-pressure-cookers.

Gold, B. (2017, October 05). The Best Electric Pressure Cooker That Will Get Dinner on the Table Fast. Retrieved from http://www.goodhousekeeping.com/appliances/pressure-cooker-reviews/g204/electric-pressure-cooker-reviews/?.

Janeway, K. (2017, November 13). Should You Buy a Stovetop or Electric Pressure Cooker? Retrieved from https://www.consumerreports.org/kitchen-appliances/electric-vs-stovetop-pressure-cooker/.

Circular Input Products Ltd. (n.d.). Tips on buying the best: What to Look for in a Pressure Cooker? Retrieved from https://fastcooking.ca/pressure_cookers/stainless_steel_pressure_cookers.php.

Pellegrinelli, L. (2011, June 11). Move Over, Microwave: A Pressure Cooker Comeback? Retrieved from https://www.npr.org/2011/06/12/137101999/move-over-microwave-a-pressure-cooker-comeback.

Statista. (2018). Retail sales of electronic pressure cookers in the United States from 2010 to 2017 (in million U.S. dollars)*. Retrieved from https://www.statista.com/statistics/514680/us-retail-sales-of-electric-pressure-cookers/.

Brains, J. (2017, August 18). The best instant pots and electric pressure cookers. Retrieved from http://www.businessinsider.com/best-pressure-cooker-instant-pot/#the-best-instant-pot-overall-1.

National Presto Industries, Inc. (2007). The History of Pressure Cooking… Retrieved from http://discoverpressurecooking.com/history.html.

This article is for informational purposes only and is not a substitute for medical advice or treatment. Consult your physician and dietitian regarding your specific diagnosis, treatment, diet and health questions.

Torie Yackanicz

Torie Yackanicz

Torie is a dietetic intern from Allentown, PA. She hopes to obtain her RD credential and pursue a career in research. Torie is a firm believer in the all-inclusive diet – all foods are welcome in moderation. In her free time, she enjoys playing her piano and drinking coffee.