Somewhere along the way, I started thinking/believing pressure cooking harmed our food. I’d heard traditional foodies say, “Pressure cookers cook at super high temperatures when we historically cooked foods slowly over fire. It’s destroys the nutrients.” Because I’ll almost always choose to go with the wisdom of experience when it comes to food and health, this argument made sense.
Then I started hearing from health-conscious food bloggers who used the pressure cooker to make rich broth in a fraction of the cooking time. If pressure cooking is so terrible on nutrients, I had to ask, why then was their broth a perfect, thick jiggly gelatin, a proof-positive sign of its mineral content and collagen goodness?
When I became concerned my ‘made-in-China’ slow cooker could be leaching lead, I started to do my research.
Would you believe it if I told you that there was a way to cook your food with the following results?:
- Much higher nutrient retention – up to 90 percent
- Better bio-availability and digestibility
- Lower harmful (potentially cancer-causing) cooking byproducts and phytates
- And up to 70 percent less cooking time and electricity
I took this info apart one piece at a time.
1 – Cooks at Lower Temperature
When researching, the highest recorded boiling point of water in a pressure cooker I could find was 250 degrees. That is still lower than the temperature that most foods are prepared at in the oven or stove top and about the same as a slow-cooker.
It’s a PRESSURE cooker, not a high heat cooker. You can BOIL water at a low temp if you have high enough pressure. It’s a scientific law.
In other words, a pressure cooking cooks foods at a lower temperature (and definitely in shorter time) than other cooking methods, utilizing the pressure to improve cooking time and efficiency.
2 – Superior Nutrient Retention
A pressure cooker can greatly reduce the time it takes to cook your food. This directly correlates with the loss of fewer heat-sensitive nutrients.
One study, published in the Journal of Food Science, pressure cooking broccoli was found to retain 92% of its vitamin C content, compared to retention rates of 78% and 66% for conventional steaming and boiling, respectively. During pressure cooking, broccoli also retained most of its sulforaphane, which was not the case when the broccoli samples were steamed or boiled using conventional methods. Sulforaphane is the powerful phytochemical that has been linked to many of broccoli’s health benefits, in particular its anti-cancer effects.) (source)
A 1995 study found that there was better retention of Vitamin C (ascorbic acid) and beta-carotene in spinach with pressure cooking than other cooking methods.
The shortened cooking time has another benefit: an increase in the antioxidant capacity of the food. A published study focusing on green peas, chickpeas and lentils found that both conventional boiling and steaming caused significant decreases in total antioxidant capacity, while pressure cooking increased antioxidant values.
Note: You can find conflicting studies that show higher amounts of nutrients were lost with in the pressure cooker, but later research revealed that most of the nutrients were transferred to the cooking liquid. Because of this, I make an effort to use as little cooking liquid as is needed when using a pressure cooker and then re-use the liquid in the meal by making a broth, sauce or gravy of some kind.
2 – Appears to Help Boost Digestibility
Pressure cooking makes legumes and grains more digestible as compared to boiling. It does so by reducing lectins and phytic acid found in grains and legumes. I explained in this post (with a time chart) how reducing phytic acid through soaking makes the nutrients in foods like grains and beans more absorbable and less likely to irritate the digestive system.
Pressure-cooking arguably increases the digestibility of protein, as shown in this study that found that pressure-cooking soaked peas brought their protein digestibility up to 84%, compared to 81% for those peas that were just soaked and boiled normally. (Note that digestibility dropped down to 74% when the peas are unsoaked and then boiled. So keep soaking!)
In another study, the phytic acid content of peas soaked overnight and then boiled was only reduced by 29%. But in peas that had been soaked overnight and pressure cooked, the phytic acid was reduced by 54%.
Other studies show pressure-cooking increases the digestibility of proteins: mung beans and rice. It makes meat more tender than boiling does (and more tender meat is demonstrably easier for our bodies to digest). (source)
3 – Pressure Cooking Helps Lower Carcinogens Such As Acrylamide and HCA’s
Pressure cooking helps eliminate two cancer-causing compounds: acrylamide and heterocyclic amines. Heterocyclic amines (HCAs) are chemicals formed when muscle meat, including beef, pork, fish, or poultry, is cooked using high-temperature methods, such as pan frying, baking, broiling or grilling directly over an open flame. (source)
High-temperature cooking of some foods, like potatoes, causes the formation of carcinogenic compounds like acrylamides. These compounds will not form in a pressure cooker. That’s because of all the steam trapped in the cooker. Those compounds mostly form in dry cooking methods like roasting, baking or grilling, or in an ultra high-temp environment like deep frying.
Swiss researchers tested this and found that potatoes cooked at high pressure for 20 minutes had almost no acrylamide formation when compared to other cooking methods.
4 – Turns Bad Starch Good (I didn’t know there was such a thing)
When a potato (and rice and pasta) is pressure cooked and cooled a large portion of its starch is converted into “resistant starch” – a healthier starch that isn’t fully digested and instead used by the body like fiber – lowering blood cholesterol and fats. See the science here.
5 – Pressure Cooking Saves Time and Money
You can cook a whole 5# chicken in 25 minutes (I even browned it with the saute mode)… make super-tender pulled pork or beef in less than 2 hours… make gelatin-rich bone broth in 30 minutes…homemade vegetable soup… cook butternut squash in 10 minutes… as well as broccoli and most other veggies in less than five!
My first meal was a whole FROZEN chicken that turned out fantastic.
I placed it frozen solid on the trivet, set it to Manual, high pressure for 30-50 minutes depending on the size of your chicken. Mine was 4. 2 pounds so I did 40 minutes and it would have been fine with slightly less time. I let steam release naturally.
I finished by browning it with herbs in the oven, but I wouldn’t have needed to to just take the meat! I must say I was afraid at first, but my confidence is building and I love my Instant Pot!
Is There a Downside to Pressure Cooking?
To be fair and balanced, while there are so many positives on the use of a pressure cooker and the science seems solid, some people still choose not to use one. Two concerns are that stainless steel may leach metal with acidic foods and that pressure cooking may increase the glutamine, most particularly in bone broth.
A genuine Instant Pot inner cooking pot is stainless steel food grade 304 (18/8), with no chemical coating, 3-ply bottom for even heat distribution. Having a secondary Instant Pot inner pot (check your size to order) makes it convenient and easy when preparing multiple dishes with your Instant Pot cooker.
Pressure Cooking: Bottom Line
Like any method of cooking, pressure cooking does destroy some of the nutrients in food, but it actually preserves more than any other cooking method.
With newer electric pressure cookers (like the Instant Pot), science is clear that pressure cooking is a healthy way to get food on the table for your family more quickly and easily while still preserving the nutrients in your food.
I would never have dreamed it made a difference in the cooking with a pressure cooker as far as the nutrients. Good info!!
Hope you are doing well. Please remember our family in PRAYER. Going through a rough trial.
Thank you, Charlotte!! Praying for you as I type, friend!
God bless you with JOY 😀
As always, good information! Thank you Jacqueline. I am wondering, do you like the “Instant Pot”? I have been thinking about purchasing one, but hesitant, as I am not one to quickly jump onto the latest fad!!! I guess I am skeptical. Anything you or anyone can share would be appreciated. God Bless.
Sue, I am learning to do a variety of things…but I am a slow learner and had to assure myself it was a good cooking method. Last night I made the best roast and potatoes (frozen meat about 3#) with whole potatoes and a package of my frozen peppers from the garden last year. 35 minutes and let it sit (natural vent) for 4 hours while I worked in the garden!!!! I t was delicious, not mushy but the roast was fork tender. Just salt and pepper and to the plates. Everyone commented! Yay! I don’t have to plan meals as much, but still so much to learn if I want to make cheesecakes 😀
Let me know if you do it and then your favorite recipe later!
Jacqueline, thank you so very much for this informative post. I learned how to use a pressure cooker from my dear Mama and Grandma. I grew up loving the sound of the pressure cooker. I’ve taught DH and children how to safely use a stove-top pressure cooker. So far, no “Lucy-type” explosions, only lots of delicious meals. Have a beautiful weekend and God bless.
BUSY MOM IN AL
I was gifted a power cooker just a week ago from my MIL who had not taken it out of the box from Christmas. Ha-ha! It is AMAZING. ? I have cooked white beans, collards (30 minutes and PERFECT), green beans in 4 minutes, spaghetti (also in 4 minutes!!), split chicken breasts and brown rice. The most amazing thing though, was an Oreo Cheesecake! Yes, a cheesecake!!
It really is quicker and I am loving trying out all the things I can save time with now. I need to try broccoli. I am working on trying to figure out sweet potatoes now that you mention the starch research.
I am getting most of my recipes from Homemaking on the Homestead. She is an awesome cook and her recipes have always proven fail-proof. She has many IP recipes on her website.
Have a wonderful day! ?
While I have used a pressure cooker, both electric and stove top, almost all of my 55 year marriage, I’ve never made my chicken stock in it. I will be trying that the next time I make it, instead of cooking it on the stove top for 5-6 hours! The first couple of years of marriage, I refused to use the electric pressure we received as a wedding gift, having seen the results of my mother’s blowing up, but finally got brave enough to use it and even canned green beans in it. I recently got a new electric one and love it.
Thanks for all of your good advice!
I’m really not sure about all this studies, all previous studies last centuries showed their negative effects, even on animals feed with them and with terrible results and now the contrary?! Not sure we can trust the actual studied paid by the companies that sells it
Thomas, can you give me the supporting information that states these studies are paid for “by the companies that sell it”, please? I did not find evidence of that, and will note that IF you can come up with them. Thanks!
I really appreciate this article, Jacque. I have held off buying an insta-pot because of the very things you mentioned. But I think you have set my fears to rest.
Thanks again friend!
Rhonda, we love ours and are just getting ready to order a second! Hugs, friend!
I love my IP! My sister tried to get me to buy one for about a year before I gave in. Now I have two, might have gotten a third if I had room. Veggies taste better, meat comes out so tender, broth is amazing! Not to mention cheesecakes and healthy sweet breads. I use mine almost daily.
Oh, Ina, to be able to make a cheesecake! I do the savory dishes and meats and broth and even yogurt, but have never done a cheesecake!
Yes, I do love mine and just got a smaller second one, too!
Thank you for sharing with me! Makes me smile!