Deep Dive
Shownotes Transcript
Welcome to Paging Dr. Gupta. This is the podcast where I get to answer your health questions, and you've been sending a lot in. Based on what you've been saying, we've got a lot to talk about. And Kira, one of our producers is here. What's our first question? All right. Hey, Sanjay. First up, we've got a question from John in San Diego, California. And this is actually something that I'm so curious about. So let's hear what he has to say.
Hey, Sanjay, this is John. I just finished listening to your Our Food Keeps Getting Recalled episode, and I had a question. My wife and her family tend to think that when food is cooked and warm on the stove, that it has to be left out until it's cool to the touch before it can be put into the refrigerator. Otherwise, it might develop some bacteria or illness.
And I just wanted to know, is that valid? It seems like it's more dangerous to leave it out than it is to put it away. So I just wanted to confirm and or deny, is it effective to leave food out when it's hot or warm before putting it into the refrigerator, allowing it time to cool down? Thank you. I love the show. Take care.
All right, John, first of all, a great question. I have to tell you, after that podcast aired in November of last year, we got a lot of questions and a lot of comments about food recalls overall and the best way to store your food. So let me answer the question directly, and then I'll give you a little bit of background. First of all, this is a common food safety myth. But at the same time, it's something that a lot of people debate. According to the Food and Drug Administration, the FDA,
it is safe to move even piping hot food directly to the refrigerator. Okay, so that's the answer. You can move very hot food directly to the refrigerator. You do want to make sure that you're not overpacking in the container and that there's enough space within the container for cold air to circulate around it. The key concern is not the heat itself, but preventing bacterial growth.
You should not let food sit out for more than two hours. That's the general rule. Because at room temperature, bacteria can multiply quickly. They say every 20 minutes, the number of bacteria can double. So leaving food out for too long gives bacteria a prime opportunity to grow and increases the risk of foodborne illness. Keep in mind, a lot of the foodborne illnesses, as much as we talk about the grocery stores and restaurants, a lot of them occur at home as well.
So where did this idea come about that you should let your food cool first before putting in the refrigerator? Well, it's actually a relic of the 19th century. This is when people used ice boxes instead of modern refrigerators. These wooden metal-lined boxes relied on large blocks of ice to keep the food cool. If you put hot food inside, you would simply melt the ice faster, and that meant you had to replace it more often, which wasn't cheap.
But today's refrigerators, they got chemical refrigerants. They got evaporator fans. They can handle hot food much more efficiently. By the way, there's a great place to read about this. It's called Refrigerator, the Story of Cool in the Kitchen from Helen Peavitt, P-E-A-V-I-T-T. If you're interested in this, you should take a look at her work.
Now, I think the real issue, though, comes about if you store a large amount of hot food, like an entire pot of soup, for example, in one container,
If it takes longer than two hours to cool before 40 degrees, bacteria can still thrive. So to prevent that, maybe divide large portions of the hot food into smaller, shallower containers. That'll help them cool faster. If possible, cover them only loosely at first. Let some of the steam escape before sealing tight. And do keep your refrigerator at 40 degrees or lower for optimal food safety.
One thing I will also point out, avoid putting hot food directly into plastic containers because the heat can cause them to leach harmful chemicals. Glass containers in this case would be a safer option. And if you plan to freeze hot food, let it cool in the fridge first before transferring it to the freezer. That can help maintain the quality of the food for when you go to reheat your leftovers.
So, John, you don't need to wait, is the answer, for your food to cool completely down before refrigerating it. The key is to not leaving it out for more than two hours. The quicker you can get it into the fridge, the safer it will be. Great question. I hope that clears things up. Now, are your microwave-safe, quote-unquote microwave-safe, and, quote, dishwasher-safe plastic containers really as safe as you think they might be? We're going to tackle that right after the break.
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. All right, new page just coming through, Kira. Give us the details. So next up, we've got Ronell from Mountain View, California with another great question. Take a listen.
Hi Sanjay, this is Renaud. I'm a recent listener, so I'm binge listening, and I just listened to your microplastics episode and had a question. You didn't address BPA, the effects of that, and whether or not that makes plastics safe for dishwashers and microwaves, because some of them say they are. So I was curious about that. I really enjoyed your podcast and learned a lot. Keep it up, please. Thank you so much. Bye-bye.
Alright, great question. Thanks for your comments. You know, plastics are designed to last, but heat from microwaving, dishwashing, and everyday use can cause them to degrade. I'll repeat that. Plastics are meant to last. They're designed to last. But all these things we do to them nowadays can cause them to degrade. And as plastics break down, they can release these chemicals that you're talking about at a microscopic level. Now, some of these chemicals are additives, right?
And the reason that's important is because they're not necessarily tightly bound to the plastic. That means they are more likely to break off. They're going to break off first, and that's what happens when they're exposed to heat or stress. And that allows them to interact with your food. Now, one of the most common chemicals, the one that you mentioned in plastics, is BPA. It's a compound that mimics estrogen in the body.
If you've read anything about it, you've probably read that. Studies have shown that even small exposures can have some effect on reproductive health metabolism. Now, some plastics are labeled BPA-free, but that doesn't necessarily mean that they are totally safe because BPA-free typically means that other similar chemicals are now substituted
and could carry some of the same risks. Some plastics containers are labeled microwave safe, but again, that doesn't necessarily mean that they are totally safe because they may have substituted with new chemicals. And again, the heat can cause plastics to break down, potentially releasing some of those chemicals into your food. Putting stress on plastic food containers by washing them in the dishwasher or with rough scrub brushes
That can weaken the plastic, that can accelerate the breakdown, and can increase the leaching. And when your plastic containers or even a well-used plastic cutting board start to show signs of wear and tear, scratches, cracks, discoloration, don't think of that as simply a cosmetic damage. Those imperfections create these microscopic grooves
which can trap bacteria and again can increase the likelihood that plastics will leach into your food. So, I don't say all this to scare you, but rather to paint a picture of what is happening to the plastics and offer these tips. What we've done in our house is we've largely switched to glass or stainless steel containers. They're more durable and they're not going to leach harmful chemicals. Avoid microwaving plastic even if it's labeled microwave safe.
if you can transfer your food to glass or to ceramic before heating. Don't store acidic foods in plastic. You know, things like tomatoes and citrus foods. That actually will break down the plastic even faster and possibly make it more likely to release microplastics. There's new data coming out on that. Stick to glass for these items. If your plastic containers are scratched or cracked or stained,
Sadly, it's time to replace them. Same for your cutting board. I know this costs money, but again, maybe switch to some glass or other material here to save yourself some money and hopefully have something that's going to be more durable. And lastly, to extend the life of your containers and reduce chemical breakdown, try hand washing them instead of using the dishwasher.
I do a lot of the dishwashing in the house because I'm not a great cook. So my contribution to dinnertime is the hand washing. I turn on some music, I get the suds going, and it's actually not bad. Hand washing some of these containers makes a lot more sense. Well, that's it for today's episode. If you have other health questions for me,
I want to know. You've been sending so many in. I really appreciate it. Record a voice memo, email it to asksanjay at cnn.com, or give us a call, 470-396-0832. Leave a message. Thanks for listening. I'll be back next Tuesday.
Chasing Life is a production of CNN Audio. Our podcast is produced by Aaron Mathewson, Jennifer Lai, Grace Walker, Lori Gallaretta, Jesse Remedios, Sophia Sanchez, and Kira Dering. Andrea Cain is our medical writer. Our senior producer is Dan Bloom. Amanda Seeley is our showrunner. Dan DeZula is our technical director. And the executive producer of CNN Audio is Steve Liktai.
With support from Jamis Andrest, John D'Onora, Haley Thomas, Alex Manasseri, Robert Mathers, Lainey Steinhardt, Nicole Pesereau, and Lisa Namarow. Special thanks to Ben Tinker and Nadia Kanang of CNN Health and Katie Hinman.
There's a reason the Sleep Number smart bed is the number one best bed for couples. It's because you can each choose what's right for you whenever you like. Firmer or softer on either side, Sleep Number does that. One side cooler and the other side warmer, Sleep Number does that too. You have to feel it to believe it. Sleep better together. Why choose a Sleep Number smart bed? So you can choose your ideal comfort on either side. And now save 40% on the new Sleep Number Special Edition smart bed. Limited time. Exclusive.
exclusively at a Sleep Number store near you. See store or sleepnumber.com for details.