Science Friday - Food Myths, Kids Flu Shot, Europe Plastics Ban. Dec 21, 2018, Part 1

Episode Date: December 21, 2018

You’ve probably heard of the five second rule, when you drop a cookie on the floor and take a bite anyway because it’s only been a few seconds. What about when you’re at a party and you see someone double dip a chip in the salsa? How much bacteria does the double dip and the five-second rule spread around? Biologists Paul Dawson and Brian Sheldon investigate these questions their new book, Did You Just Eat That?: Two Scientists Explore Double-Dipping, the Five-Second Rule, and other Food Myths in the Lab. They talk about how bacteria spread around in our everyday lives and what can be done for food safe handling in our homes. What is the right age to get a flu vaccination at a pharmacy? In North Carolina, apparently, it’s 14. The age limit was written into state law a few years ago. Across the country, age limits for pharmacists to give vaccines range from 3 years old in some places to 18 in others. But why? Since the 1990s, states have been changing laws to allow pharmacists to give more and more vaccines to patients at younger ages. In 26 states and Washington D.C., pharmacists can give vaccines to people at any age. The rest have varying limits starting as young as 3-years-old in Arizona and as old as 18 for vaccines in North Carolina—except for the flu shot.  This week, European Union leaders signed a provisional agreement that would ban 10 major single-use plastic products, from plastic straws and cutlery to Q-tips with plastic stems. The agreement would need to be ratified by EU member states, likely in the spring. If approved, the ban would be implemented in 2021. Rachel Feltman, science editor at Popular Science, joins Ira to talk about the proposed ban and what it might mean in the EU and elsewhere.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

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Stick with me. You're going to want to hear this. But first, we all. know that plastics in the environment are a big problem and recently came word that an effort to clean up some of the plastics in the Great Pacific Garbage Patch is not going as well as planned. In Europe, though, there are moves to tackle the problem closer to the source. The EU is finalizing rules for a ban on many single-use plastic items. Rachel Feldman, Science Editor at Popular Science is here to fill us in on that and other

selected short subjects in science. Welcome back, Rachel. Thanks for having me, Ira. Okay, so why is the EU rule a big deal? Yeah, well, it's a big deal because obviously there's been a lot of talk on single-use plastic bans. It's an obvious place to start when we talk about dealing with plastic pollution. It goes without saying that something that's used once or twice before being thrown away is a bigger problem than a plastic item you bring into your house to use for a year, five years, whatever. So this would be the biggest region that would undertake something like this.

And it kind of begs the question of why North America isn't doing something similar. You know, I think in the U.S. we may start to see states banning single-use plastics. But we're really really just starting to see plastic bag bans, straw bans. So for the EU to take such a broad stance banning, I think it's 10 different items. Plastic cutlery, plates, straws, styrofoam takeout containers and cups, Q-tip sticks, and oxodegradable plastics, which includes most plastic bags, for them to take such a big stance. It's a big deal.

And one of the hot gifts this holiday season are metal straws. You can buy people in a nice pack. There are lots of options for reusable straws. It's a good place to start if you can. Let's move on to a story from the National Zoo. That sounds like something out of Game of Thrones. Yeah, so people were really excited that the National Zoo had a few weeks ago, they had announced that there was a power vacuum in their naked mole rat colony.

Oh, no. And a few days ago, they announced that a queen had emerged from a bloody and long-thought struggle. Really? Which is, I think, you know, people love the juxtaposition of, like, royalty and naked mole rats, because frankly, naked mole rats are really ugly. They're very squirmy and pale and pretty much blind, and the idea of them having a queen is just kind of inherently funny. How do you have a battle?

Well, that's what I love about this is that once you look more into the story, it becomes really fascinating. So naked more rats are U-social, which is the same kind of social structure that ants and bees have. It's like that hive collective where there's only really one like independently operating member of the colony and everyone else is just functioning for the common good. And in fact, there's just that one reproductive member of the colony, the queen. and there are only actually two mammals, by the way, that are you social, and they're both kinds of mole rats, naked mole rats being one of them. So they have this really unique social structure, and it means that whenever a queen dies, the biggest females will start fighting with each other, and whichever one lives long enough to get pregnant and reproduce, then becomes the queen. And once there's a queen in place, something really interesting happens. No other females are fertile, but more specifically, they don't have mature sex organs.

It seems like the queen is able to shut down puberty. And in fact, any male she doesn't want to reproduce with also don't go through puberty. And that process starts up again as soon as the queen is gone. So it's just very weird and cool. I see you're not interested in this. As we all know, the holidays are upon us. and there's some news about holidays and your health? Yeah, so this study came out claiming that Christmas Eve is the deadliest cardiovascular day of the year.

And there are some caveats. The study only looked at Sweden. So it is the biggest day for heart attacks in Sweden. But of course, we can't apply that to the rest of the world. However, there is a lot of research already that shows that heart attacks are more common. on holidays. And there's already research showing that if you live in a predominantly Christian country, that Christmas is probably the deadliest day of all, which just is scientific proof that we're all actually horribly stressed out when we're surrounded

by our family. Not to mention depressed. For years, we've read about depressions going up. Right. I mean, it's a joyful time, but it's also a very stressful time. And people are also eating strange foods and traveling. And it's just kind of a perfect storm if you're already at risk of a heart attack. This is unbelievable to add something else. To be stressed about stressing about it. Exactly.

Yeah, but one related thing is that there was another study showing that people who are discharged from hospitals during the holiday season are more likely to die afterward just because they tend to not follow up on their care. So one thing you can do is that if you're unfortunate enough to end up in the hospital, you know, make that follow-up appointment and follow the instructions. Don't feel like you're being a buzzkill because you're dealing with your health. A lot of it can be prevented by just advocating for yourself and taking care of yourself. And finally, there is a distant space object far, far away. Yes. In fact, scientists have named it far out. Is that right?

Yes. That's the official name. Yes. Far out. Somebody from the 60s named it that, I'm sure. But it's about 120 to 130 AU away, an AU astronomically. unit being the distance between the Earth and the Sun. And Pluto was only 34 AUAWA. So this thing is really far out. That's far out man then. Yeah. The thing I love about it is that the most distant

objects that we consider part of the solar system are actually like tens of thousands of AUs out. So this is just a reminder of how much space there is in just our solar system and how much room there is for perhaps a planet nine to be hiding. So this is something maybe the size of Pluto or something smaller? Yeah, you know, it's still too soon. They're saying maybe it's a dwarf planet, but it's, they don't have enough data to tell. But it's definitely like a large asteroid at the very least. Far out then.

All right, Rachel, thank you very much. Yeah, thanks, Sarah. I love. Rachel Fultman's Science editor at Popular Science. Thanks for being with us today. Thanks for having me, R. And now it's time to check in on the state of science. This is KERNO, St. Louis Public Radio News.

Iowa Public Radio News. Local science stories of national significance. Okay, picture this. Flu season is coming, so you decide to drive the whole family over to the local pharmacy to get vaccinated, right? But when you get the air, your teenager is denied the shot. Why is that? Well, the rules for vaccinations differ from state to state. And in some states, there's an age cutoff for getting a farm.

Pharmacy vaccination. Joining me to talk about that is Alex Olgan, health reporter at WFAE in Charlotte, North Carolina. Welcome to the show, Alex. Thanks, Ira. So why can't everybody get a flu shot at the same place? Because of state laws. Like you said, each state has different rules about what vaccines pharmacists can give if they can give vaccines at all. Like in North Carolina, they even list out which five vaccines other than the flu shot pharmacists can give. and then they have this like special exception and special age limit for the flu shot.

And, you know, the expert I talked to has been studying this and said since the 1990s, you know, states across the country have been expanding pharmacists of vaccine authority. So what is the age limit in North Carolina for the flu shot? So for the flu shot, you have to be 14 or older. And that was relatively recently changed. If you remember back to 2009, the swine flu, pandemic, I actually got swine flu, although I was not living in North Carolina. So the state medical board said, we need to grant some emergency authority and let pharmacists give these flu vaccines to people as young as 14. And then in 2013, the state lawmakers said, all right, let's codify this. And they put it into state law.

So how many other states have these kinds of rules? So all across the board, and they vary. So some states say, well, pharmacists can give vaccine, but then you also have to have like a prior authorization from. a doctor or primary care physician or they can give the flu shop, but they can't give other vaccines, so it's really all over the map. So, you know, last we checked, in 26 states in D.C., pharmacists can give vaccines to people at any age. But like I said, there's all kinds of different limits.

So you have varying limits. Three-year-olds can get them in some states, but not other states. Yeah, Arizona allows people as young as three to get vaccines at the pharmacy. You know, it's kind of a public health question, right? If you want lots of people to get vaccinated, should we make it easier for them to get vaccinated, a.k.a., like you said, take the whole family to the pharmacy and get it all done at once. Can other, you know, I heard a story that a doctor, a dentist can give the vaccine to? Yeah, so I asked the American Dental Association about this,

and they said that in Illinois and Minnesota, those states are now allowing dentists to give the flu vaccine to adult patients. Again, there's that age limit. You've got to be 18-year-old. I think some of the public health theory behind this is, you know, if someone is coming to the dentist every six months, but they're not going to their primary care doctor, let's just get it to them while we can. And let's not forget the economic side of things because, you know, with the ACA, as it is, I guess, before it was declared unconstitutional, all preventive care is covered. And so you have to, insurance companies have to pay for the flu vaccine.

So whoever gives the vaccine can get reimbursed. You know, that makes a lot of sense because if you think about it, people do go to the dentist for a cleaning or something much more than they probably go to the doctor. People wait five, ten years to go to the doctor sometimes. Right. And so do you think that states are going to basically change their rules about the vaccination and when they can allow teenagers to be vaccinated? So it's funny you mentioned that.

I just looked it up. And earlier this week, New Jersey signed, the governor there, signed a law expanding vaccination authority to pharmacist interns. Of course, they have to be supervised by a fully licensed pharmacist, but that was, to my knowledge, the most recent expansion. I know there has been some murmurs around the state, you know, that pharmacists are not thrilled that there are these age limits. But, you know, the state law here actually says that if someone goes to get a vaccine,

the pharmacists are supposed to tell their primary care doctor. And if the patient says, well, I don't have a primary care doctor, then the pharmacist is supposed to tell the patient about the benefit of having a primary care doctor written by some of the doctors' associations in North Carolina. Well, if you're 13, you know, try to tell a teenager. Exactly, exactly. Okay. Thank you, Alex.

You're welcome. Have a happy holiday. You do. Alex Olgian is health reporter at WFAE in Charlotte, North Carolina. And when we come back, we're going to take a break in. And we're going to take on some of those food safety questions, you know, just in time for the office holiday party. is it safe to double dip in the cheese dip? What about, you know, spreading germs on all kinds of stuff?

We have a couple of expert biologists who are going to talk about this. We'll even play a little classic piece from Seinfeld with George in it. You're going to love this segment. Stay with us. Be right back after this break. This is Science Friday. I'm Ira Flato. If you're a Seinfeld fan, perhaps you remember this classic moment.

George is at a party, just like the kind you're going to be attending this holiday. season. People are schmoozing, eating the crudete. Then he's caught double-dipping his cracker into the dip. Double-dipped? What are you talking about? You dip the chip. You took a bite, and you dipped again. So that's like putting your whole mouth right in the dip. Well, does double-dipping a chip really infect the dip? What about the five-second rule? Will you drop some food onto the floor? Is it too germy to eat? And how about this holiday favorite? Does spiking the eggnog kill the bacteria? You know, the alcohol in it.

My next guests are two biologists who investigated these food questions we've all thought about. In their new book, Did You Just Eat That? Two scientists explored double-dipping, the five-second rule, and other food myths in the lab. So if you've got questions about the bacteria and germs around us this season, like when you blow out the candles, do you spread your germs all over the cake? These two guys are here for you. If you have a food of your myth, you're wondering about, our number is 844-724-8255, 845, 844-724-8-255,

or you can tweet us at SciFRI. Let me introduce my guest. Paul Dawson is Professor of Food Science at Clemson University in Clemson, South Carolina. Brian Cheldon is Professor Emeritus of Food Microbiology and Poultry Science at North Carolina State University in Rale. Welcome to Science Friday. Thank you, Ira. My pleasure.

Paul, you actually teach a class about these questions. Do you all think about like the five-second rule in double-dibbing? In a sense, yeah, we have a program called Creative Inquiry here at Clemson. And the purpose of the class is to expose students to research. So rather than, or in addition to going to a lab, if we've all remembered our labs back when we're in high school and college where you kind of receive a list of things, the order of things to do, So in these classes, the students come and they address a problem or an issue, everyday issue, and they get some choice in that, and we attack that in the lab, so to speak, with a scientific method.

And as you mentioned, some of these in the intro, these are the ones we've used to teach the students how to do research. Let me go right into that clip from George Costanza, double dipping. Let me ask right out, is that a dangerous thing to do? Well, I guess dangerous is how you approach it, but the fact the matter is we did find that you do transfer oral bacteria to the dip. So if the people in the room are your good friends and you feel comfortable exchanging saliva with them, if you will, then it's not a problem. But as you know, at this time of year in particular, we're concerned about the cold flu and influenza and the common cold and so forth. I guess there is some risk in doing that. Brian, I was going to ask, what are the most common bacteria and viruses that like to munch on our food?

Well, that's quite a variety. There's thousands of literally mains of organisms that comprise our bodies itself. It's been estimated somewhere like 5 times 10 to 30th organisms on this planet, and about 39 trillion actually reside in or on our bodies. And fortunately, about 99% of those are seemingly harmless or actually have beneficial uses for us. Only about 1% of the known bacterian viruses actually are pathogenic or disease causing. So relative to, I mean, these organisms, just like us, they need to metabolize. They need a nutrient source.

And they carry on all the functions that we do. They reproduce, they communicate. they are able to move. And so consequently, they're going to be in about every environment that we're in. And we can't do anything without them because they are part of us. And it's just a matter of that is that 1% of the organisms that land in that dip. Like Paul said, essentially, you know, is there a cold virus or a flu virus or, you know, pneumonia, virus or bacteria? area in that, you know, in that dip or anything that we touch, too.

And it could contain these organisms. So it's a matter, really, you're playing the odds. There's always a risk associated with anything we do in life as a matter, you know, how great is that risk. And, of course, the risk for us also depends upon, you know, our immune systems themselves. You know, if they were very aged or very young or immunocompromise in some way, obviously we're going to be at greater risk. and engaging in these types of practices like double-dipping and just everyday life.

Let me hone in on a few things that people do or people think about. Is there a time, a set limit of time that you can allow the food to stay on outside on the serving tables before they go bad? Or does each food have its own clock on it? This is Brian again. I'll jump in on that one. and Paul can follow with additional information if he cares too. Well, the recommendation is that the food not stand on the countertop or the picnic table for more than two hours. That's dependent upon what the atmospheric conditions are, the environment.

You know, if you're out there in that proverbial summer picnic and it's 90 plus degrees, and you have a, let's just say a meat-containing product, a chicken-containing product, it's sitting out there at 90 degrees. we've did some calculations. If you had like 40 cell manila cells per gram of material after four hours, you would have something like 2.6 million cells. So we're inside in the holiday season, inside someone's living room or kitchen or something. The recommendation is still to be within two hours.

And some, actually, if the conditions are too favorable for growth of the organism, within 30 minutes, you ought to be refrigerating it. Wow. Do you want to add anything to that? Well, yeah, I guess, obviously we're talking about casseroles and food that are perishable and left an Eminem and out on the table. You know, it's not going to be a problem. There are different.

Some foods are very shelf, we call shelf stable. So, yeah, I mean, obviously we are considering the casseroles like Brian mentioned. Let me go to the – we have a lot of people calling in. Let's go to the phones early. Josiah in Harrisburg, South Dakota. Hi, Josiah. Cool. Hey there. Okay, so my question was, is it bad if you take the, like, if you're cooking some food and then you take it out and give it a taste and then put the utensils back in, is that bad?

Hmm, good question. You're tasting with a spoon. Is that a bad thing because it's going back into the sauce or whatever you're making? Yeah, that's actually kind of one of the chapters we did a study on sharing food, if you will, We actually, because we talk about it in some cultures that's common, and even our culture, we share food or actually taste food, as I was mentioned by the caller. So, again, we go back to the double dipping. You are transferring oral bacteria to the food when you do that. So, again, if you're going to keep, Brian can jump in again after I finish,

but if you continue to cook the food, that may take care of that. But doesn't it get destroyed by the heat? If you're boiling soup or something, doesn't it? Oh, yeah, if you continue to cook it and cook it after. But if it's like the last few minutes of the cooking or whatever, you're probably not going to have. Because I mentioned it's a time and temperature, both growth-wise and destruction-wise for bacteria and viruses.

It's a time and temperature combination. So, you know, 10 seconds at a particular temperature is not the same thing as a minute or 10 minutes or whatever. So tasting is not bad if you're going to. to cook it fully after that. You know, that's why you see professional chefs, when they want to taste something, they take a piece of bread and dip it in, and then they taste it. They don't actually take the spoon or something. That's probably a good practice.

At least we hope they do that. Okay, Paul, let's talk about the, everyone has heard of the five-second rule, right? You can eat something off the floor as long as you pick it up within five seconds, and you actually tested that app. There's a history to this idea, right? Where did it come from? Yeah, we did. That was also a fun part of the book. And most chapters we go back and we talk about food habits or practices and like blowing out birthday candles or the five second rule, we tried to figure out where it started. And really, we couldn't find it, I don't think there is a definitive origin of the five second rule. But there are some writings in history. Actually, Genghis Khan made some statements about if food was left, if food was prepared for Genghis Khan, then it was good enough to eat no matter how long to stay on the floor. So he had the con rule. and then really there's a video or tape of Julia Child dropping a potato pancake on the stovetop and making comment,

it's fine to put it back on the plate if nobody's in the kitchen, did you? So that may have been the origin of that, but we actually, there's kind of two questions there, and that's kind of part of the learning of the creative inquiry studies we did. You asked the question, is it safe to eat if you pick it up in five seconds, whereas we really tested, is back to your transfer if you pick it up within five seconds. And those can be two different things because it depends on really what surface you drop it on. So we really, in our study again, and again, the part of the nice thing is I learned a lot

and the students learn how to go about and create an experiment. So we went to a local home supply store and bought small, like four or five inch square pieces of carpet, tile, and wood flooring. Took them back to the lab, sterilize them. Then with salmonella and then actually left the two things, let the salmonella on those surfaces for different periods of time before dropping food, baloney in our case, and white bread, and then picking it up within five seconds, 30 seconds, or 60 seconds,

and then measuring the transfer of bacteria to that food. And, again, probably not surprising to most people is it was transferred within five seconds instantaneously, essentially. So if there's contaminated, if the surface is contaminated, the five-second rule was a myth. There you go. Let's go to the phones to Jimmy in Englewood, New Jersey. Hi, Jimmy. How you doing?

Great show, great topic. So just to piggyback on that transfer rule, say if I had a slice of pizza in the kitchen and I dropped its face down on the floor, the cheese, and then I pick it up and run some, you know, cold or hot water. you know, over it. And again, you know, just piggybacking on that what would happen. Yeah. Can you rinse stuff off that's

dropped on the floor? Well, I think obviously you're going to have some impact. You're going to be able to rinse some of the organisms off, but be able to get a totally to say, use the word, sterile product by just simply rinsing. You're not going to be able to achieve that.

And then it comes down to the question of, you know, what was on that floor to begin with? very well could not be any pathogenic organisms, but then again, there could be. If you have a dog or a cat that's in the family, and they're going back and forth across the floor, and of course they enter the litter box, you know, there's a good chance there could be a pathogen in there.

The rule of thumb is that when in doubt throw it out. You know, it's not just a dog and cat. We walk in with our shoes from the street, right? Yes. Yes. I didn't want to blame the dog. and cats, obviously we carry a lot on our shoes as well. Let me ask you about the candles question.

If you blow out the candles on a birthday cake or whatever kind of cake, are you spraying the whole cake with germs? Yes, a short answer to that is yes. In fact, in our studies, and this is fun part too, just a little background on that. We were concerned about actually the top of the cake, the icing, so we created a really a faux cake, if you will. we had styrofoam and then put a layer of a sterile aluminum foil and then actually put icing on there and we used styrofoam so we could actually stick candles through the

through there through the icing to simulate a party and we try to do it as real as real world if you will as we can actually had the subjects eat a slice of pizza or take a bite of a slice of pizza kind of get the saliva going and then blow birthday candles that as if it were a birthday party we found uh as you might guess some of these studies we did, you find high variation from person to person. In this case, an average of 3,000, almost 3,000 bacteria transferred to the cake versus virtually not. And we ran to control, if you will, we did the exact same thing, set it up with the icing and candles, lit and everything, and just removed that without blowing on there and compared blowing on there versus not blowing on there

and found, like I said, almost 3,000 bacteria on the cake that was blown on on average. but actually one cake was we found 37,000 bacteria. So huge variation, as you might expect, and you can imagine a scenario. We have a very young child or very, we use a scenario in the book where you have a 90-year-old grandmother or grandfather having a birthday, so there's actually a lot of candles on there, and then they enlist the help of their grandchildren

and help them blow the candles out, so you're getting a lot of saliva going. And actually, actually, just talking like we are now, you're generating what they call bio aerosols, and they are large enough compared to a bacteria, the bacteria in your mouth oral bacteria, to ride along. So we're generating... I have to generate a bioarisol at the moment

to remind everybody that I'm Ira Flater, this is Science Friday from WNYC Studios. Continue that thought, please. Okay, so you can imagine then if we're just talking now, we're generating those into the air. What, first of all, blowing will do, and certainly you're blowing forcefully to blow candles out, you're going to be blowing oral bacteria

and bio-a-a-a-a-a-a-a-a-sols on the top of the cake and directed in that direction. Right. And as Brian mentioned earlier, there are well-known, some infectious diseases that are carried from saliva, tuberculosis, pneumonia, flu, SARS, lesionnaires disease.

And again, I guess, I'll step back a little bit. I'm not trying to scare anybody, but because you can tell by the name of the book, We're not trying to scare people, but there are some serious topics. And if someone's at a birthday party who is immunocompromised, you probably want to be a little more cautious of blowing the candles out or serving them the cake. Well, what's my question? After you've done all this research and you specialize in this, are you more germophobic now or less fearful? I think for myself, I just Paul, I'm less fearful.

I mean, nothing new. and as Brian said before we lived our lives pretty old now I guess and eating three meals a day 365 days a year and sure we probably all had a bout with food to Bourne Hills but in general it's been very healthy

and not going to change too much what I do I am aware of in public places I think I've always been aware of a little more aware as an adult has done some studies washing my hands and maybe not touching some surfaces before I eat and then go not using not touching my face with my hands and so forth but in general

you know I'm not going to not eat a birthday cake because someone blew the candles out our number eight I've got about a minute to the break so if you can get that in that comment go ahead the only thing I have to say is that you remember when I gave the statistics about 99% of the microorganisms are seemingly safe to us and only about 1% are problematic so I kind of use that rule of thumb. And as Paul said, I like to take some caution in cleaning my hands and what I touch at a restaurant, you know, menus, et cetera. Right. Well, we'll talk more about that because we have lots of phone calls, lots of tweets coming in about, you know, shaking hands during the holiday. I'm looking at some of these fist pumping. Is that better than a handshake?

All kinds of stuff people want to know because we're going to be greeting. And, well, how about kissing on the cheek? We'll get into some of the stuff after the break. Stay with us. I'm Ira Flater. Are you listening to Science Friday? We're talking about the book. Did you just eat that? Two scientists explored double dipping, the five-second rule,

other food myths in the lab, with Paul Dawson and Brian Sheldon, a great book. I recommend everybody get a copy of this. I want to go to a tweet that's actually close to my heart because I'm sort of guilty of doing this. It comes from Mary Kate. It says,

my stepmom used to get mad at my dad for reaching into the pickle jar with his hands. He'd reply, If this can pickle a cucumber, it can pickle my germs, too. I mean, I want to know as someone who ferments my own pickles, and I'm guilty of doing that, how right or wrong

is he? This is Brian. I'll take a stab at this, and Paul can follow. It really depends upon the pickle we're talking about a deal pickle versus a sweet pickle. The composition of the deal pickle is going to have

much more acid in it, vinegar in it, not only besides, you know, the fermentation of that occurred, but it's the assets really controlling the microbial growth. And if we're talking about a deal pickle, you're probably going to be able to get weight. It also comes down to how dirty the person's hands are. But for the most part, the organism, most bacteria pathogenic organisms cannot resist or cannot survive high asset content products such as dill pickle juice. Is that why ketchup can sit out forever almost because it's got a high acid in it or other condiments

and they don't go bad? Yeah, well... Basically, Paul, you can take this then. Yeah, well, exactly. Even mayonnaise has a high enough acidity if you don't add other things to it. Manage gets a bad name, but if it's just mayonnaise itself,

it has a low pH, if you will, or high acidity, and that prevents bacteria. To their shelf stable, can kind of walk through a grocery store and see things that are, what's called shelf stable, that aren't refrigerated or canned, haven't been heated, like you mentioned, ketchup, mustard, and others. So, yeah, that's exactly why. So in the picnic, in a picnic, it's not the mayonnaise that goes bad, sitting out with the potato salad or the, you know, chicken salad?

Well, it's a, yeah, well, Brian, and you jump in, that's right, yeah, the potato, you've mixed potatoes in there or chicken in there, and that's diluted, or most, or a, buffered the acidity, so then it's not no longer, the environment is no longer low enough pH to prevent growth, and you've probably, you may have inoculated the mixture with something by adding something to that salad. So I would, I'd just kind of doing this off the fly here in my mind, but I imagine if we did an experiment and try to mix something in with ketchup, you might have the same result if you dilute out the acidity. Let's move on to another topic. Let me, Should I go to the phone?

Let's go to the phone. Let's go to Josh in Boston. Hi, Josh. Hello. Hi there. Go ahead. So my question is about food items that may have acquired some mold on them, such as maybe a piece of broccoli.

And there's only a small amount of mold on it. And if I was to take off that small amount of mold, is the rest of the vegetables good to eat? Yeah, cheese has always had some mold growing on it somewhere when they keep it around. Yeah, that's a good question. This, Brian, and again, just because you don't see it, doesn't mean there's not mold spores there. Most of the microorganism, before they reach a certain population, they're invisible, but they're there.

For the most part, though, most molds are not pathogenic to us or not toxicogenic to us. I suspect that those that are growing on the food are not. But there are some molds, though, that produce toxins and aflatoxins, etc., that are very toxic to humans. But for the most part, I would not presume that they would be on broccoli. But, you know, washing, obviously, or cutting off the part of it. I've eaten many moldy bread before because I could actually taste it. You couldn't see it, but you can taste the mold in there and did perfectly fine with it. Let me ask you the question about raw cookie dough.

People love raw cookie dough. Is it okay to eat raw cookie dough? Well, the FDA and CDC are worn against that. And then I know recently there was an article by a fellow from University of Michigan who actually is involved in the health field saying that he didn't say it was okay. It just kind of had a rhyme there. If you really enjoy it and you're willing to take the risk, it's up to you. But the fact of the matter is, there's really two parts of that dough that can be dangerous.

It's the flour can contain, and it has contained in the past found contaminated flour, and also the eggs if you use egg in the batter. So those can contain pathogens. Of course, they don't always contain pathogens. So it's, as I use the analogy in the book, is kind of like wearing a seatbelt. You can eat raw cookie dough your whole life or never wear a seat built your whole life. And if you don't have an accident or don't run into some cookie dough that's contaminated, you're going to be okay. But you hit the one that is, and you're mostly going to get hurt.

So, you know, if you have an option, and there's actually are some cookie doughs at there now that have been sold on the market that actually are safe to eat raw. They're made without eggs and also the heat, the flour is heat treated. So people who like to eat raw cookie dough can go that route if they so choose. So, again, it's a matter of you're taking a chance, and if you have an option that guarantees you're not going to get sick, I would not chance it. Let me go to the phones to Adam in Chicago. Hi, Adam.

Hi, this is Adam calling from Chicago, and I was wondering if it's just as dangerous to do a waterfall, like when you just pour the drink in your mouth or actually touching it, if it's sharing it with your friends, if it's just as dangerous to do that as it is actually, like, drinking the beverage from the actual bottle or cup. Okay. Brian?

Or what's the call? I'm not sure I understood the question that you're not old enough. You're too old to understand that, actually. I think if I understand the question, if I understand the question, you have a water, squirt water bottle, and rather than putting your lips on the bottle, you squirt in your mouth. And I would say if you're not contacting the water, the bottle,

and there's no chance that's where we use is backwash. You're not contaminating the water in the bottle, so that is safer. And yes, sharing water bottles is highly frowned upon by the health industry and medical industry. And there's certain, actually, I was reading as part of the background that the sports, so on the soccer associations in the, I think New Zealand actually has a big, you know, a problem with that. They have a warning of that. So that's a good question.

Yeah. That's why you see athletes, you know, at football games, they're squirting it into their mouth without touching it from the bottle. Let's talk about the ultimate holiday raw egg food, which is eggnog. Now, if you spike the eggnog, does alcohol kill the bacteria in the eggnog? Well, it's, you know, there's been some studies done in action. I think a show appeared on your show. Yeah.

number years ago with microbiologists from Rockefeller University. He had made a batch of eggnog, which he had spiked with a salmonella test drain. And they refrigerated this for three weeks, and they measured the populations over that three-week period of time, and saw that there was a reduction in the population and ultimately elimination of the organism after three weeks. although I would say that, you know, the Food and Drug Administration frowns upon that. They recommend that if you're going to do make an egg gong that's spiked with alcohol, that they recommend that you start with a cooked egg base beginning. In other words, if the recipe has milk in it, you take half that portion of milk plus the egg

and you heat it constantly stirring up to 160 degrees Fahrenheit, and that should be sufficient. If salmonella is present that you would have killed. it. Then you essentially allow that to refrigerate to cool down, then you add the rest of the recipe to it, the milk to sugar, the flavorings, et cetera. The recommendation is that you should never count on the alcohol, you know, actually sterilizing the product. And again, back to that example of that study at Rockefeller University, that was three weeks sitting in the refrigerator. Who's going to make eggnog and let it sit in three weeks before they start consuming it? This is

usually made a day or two before the event and you start drinking it immediately. Yeah, speaking of salmonella, let me just, something that just popped into my mind that we hear all year, but maybe should be emphasized again in this cooking season. And that is never to wash the chicken before you use it, right? Right. That's a good one, yeah. The reason being you can aerosolize the salmonella, spread it around the kitchen, the sink, counter. You're going to cook it anyway, and you're going to destroy, if cooked properly,

you'll destroy all the pathogens or salmonello on that product. So by washing it, you're not really giving yourself any advantage. And secondly, there's a good chance you're spreading it around the kitchen. Yeah, let me go to the phone. Let's go to Amy in Manhattan. Hi, Amy. Hi, hi there. Go ahead. Amy, are you there? Sorry, yeah, yeah. So I'm having a problem with my earphone. Yeah, I was wondering on the double dipping. Suppose you hold your chip or whatever you're dipping in the middle, and you dip each end, you know, dip one end, bite it off,

and then dip the other end without moving your fingers. Is that the make it safe? Well, yeah, except your actually your hands now are what's contaminated. If so, you're not getting oral bacteria. That's a good way to avoid the oral bacteria. But, yeah, so I guess the hands are a real concern of a way bacteria is transferred as well. But, yeah, that's a way to avoid that. And I'm glad you asked that question because one thing, kind of one of the interesting things

you found out in the double dipping was we actually used, we tested salsa, chocolate and cheese dip and found there was more transferred to the salsa than there was to the cheese and chocolate. and we thought about this because it's a thinner dip, it's and more is falling back in there. And relative to the Dill Pickle question, actually the salsa, we let the dip sit there two hours and actually saw a reduction in the number of bacteria in the salsa,

but it was still there. So I guess to add on to the Dill Pickle question, it depends on how long in contact the bacteria is with the acidic environment, and even after two hours in the salsa, which is pretty low pH, it still wasn't gone. Let's go to Merritt from Vale, Colorado. Hi, welcome to Science Friday. Hi, happy holidays. I love your show. Thank you. I have a question for your experts based on a secret I've kept for years and years. My family always had really large Thanksgiving dinners, tons of people around,

and in the hustle and bustle of cleanup, my uncle put together a plate of this, left over scraps a few things, took it outside and let his dogs have it, brought the plate back in, put it on the kids' and counter, and there was one lone piece of asparagus that the dogs didn't eat. And my grandmother, who hadn't seen this, walked by, picked up the asparagus and ate it. None of us ever told her. He's no longer with us. The asparagus has to do with that. But I was just wondering kind of what your experts take on. that was the cheapest eighth of asparagus.

And, you know, in general, we have lots of cats and dogs around. People do all kinds of things that I think are kind of gross, feeding the dogs from the table, letting the cats walk around. So I just wondered about, you know, the introduction of pets. Before we get that answer, let me remind everybody, because it's going to be a long

answer, I think. This is Science Friday from WNYC Studios. Talking with Paul Dawson and Brian Sheldon, authors of, did you just eat that? And go ahead. Who wants to jump in on that one? Well, I hope the sparrison had anything to do with the passing of the relative. Well, assume it hasn't. Okay.

No, I suspect it hasn't. And I go back to the original scenario that, and Paul actually mentioned it, that we eat, you know, 365 days a year, three meals a day if we're lucky, and we don't always get sick. And we have animals and pets, and, you know, we eat in, we eat out. but then again, there is a risk associated with this. Again, dogs and cats may appear to be clean. Obviously, they don't wash their hands, or their feet, their paws. So consequently, there's a greater risk that the organisms that they have on their paws or in their mouth are those things that they've picked up elsewhere that could very well be containing pathogens.

You know, there is a risk associated with it. how great that risk is, you know, I don't think any of us know. You could calculate something like that, but I suspect that there still be small, but I would never, and the animal can appear to be clean. The surface can appear to be clean, but it's, you know, it has microorganisms on it, and it's just a matter, are they pathogenic in nature? Let me go to Richard in Fort Myers, Florida, because he has a question I have at least half a dozen people asking. Go ahead, Richard.

Yes, I have a question regarding time. toddlers. And, you know, little kids in general are running around dropping food, picking up food, seeing something that they like, put it in their mouths, et cetera, et cetera. Yeah. And along with that, I'm wondering if that doesn't help them to build an immunity to organisms that may exist in that environment. Let me get an answer to that.

You know, all these toddlers, they're crawling on their four limbs or are they standing up? They're picking up the food. Is this good? Should we stop them from doing this? Well, you probably can't stop them. First of all, and certainly it does help the immune system. And there's a lot of, as Brian mentioned early on, I think, about the microbiome. There is a lot of research that the bacteria in our body and other microorganisms are very important to our health.

That's been well known, but there's a little more being explored in that area and certainly exposure to, bacteria and viruses at a young age helps build the immune system. And I guess the caveat to that would be we all as adults experience it, and now we have for strong immune systems. There are some things that overwhelm the immune system in some cases and certainly don't want to risk exposure to that. But yeah, a quick answer to that is yes, it certainly does, I would say. All right.

We have run out of time so much to talk about. I want to thank both of you, Paul Dawson, Professor of Food Science at Clemson, Brian Sheldon, Professor Emeritus at North Carolina State University in Raleigh, authors of the book, did you just eat that? Did you just eat that? That's a great book. You can read an excerpt from the book on our website at ScienceFriday.com. Thank you for joining us today.

Have a great holiday. Before we go, I want to take a minute and thank all of Science Friday's donors and people supporting their local stations with gifts. individual contributions are a large part of public radio success, and if you haven't made your end-of-year donation, please consider doing that. So, you know, public radio needs your support. It's a great last thing of the year to do. Charles Berkowitz is our director, senior producer Christopher Taliatta.

Our producers are Alexa Lim, Chrissy Taylor, Katie Haller, technical engineering help from Rich Kim, Sarah Fishman, and Kevin Wolfe. We're active all week on Facebook, Twitter, Instagram, all of social media. and once again if you want to read an excerpt from the book we talked about did you just eat that two scientists explored double dipping the five second rule of the food that's in the lab you can read an excerpt on our website at science friday dot com I'm Irafledo in New York