Short Wave - Bee Superfood: Exploring Honey's Chemical Complexities

Episode Date: November 18, 2021

Honey bees know a lot about honey, and humans are starting to catch up. Scientists are now looking at how the chemicals in honey affect bee health. With the help of research scientist Bernarda Calla, Short Wave producer Berly McCoy explains the chemical complexities of honey, how it helps keep honey bees resilient, and what role it may play in saving the bees. Read Berly's full story on honey in Knowable Magazine: https://bit.ly/3qIXRN3See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Emily, do you like honey? Burley, if by honey you mean the real reason I drink tea, then yeah, I do. Yes, yes. And you know, honeybees love honey. Oh, yes, they do. It's in their name. They make it.

They store it. They use it for a backup food supply when there's not a lot of nectar around. And, Emily, honey is so much more than a sweet treat for bees. And so it's not just sugar because bees cannot survive just in sugar. Wait, honey is made up of more than sugar? Yes, a lot more, Emily. I talked to Bernardo Cala, a research scientist at the University of Illinois at Urbana-Champaign. She studies how plants and insects interact.

And Bernardo says honey is food and medicine for bees. And this medicine is not just one component, but several components for different types of diseases or stresses that the bees might be exposed to during their lifetimes. Wait, you're telling me that honey, this ambrosial-like substance that I love, is medicinal for the bees too. Yes, and they seem to know it's good for them. One study that I read found that sick bees, when given a choice of different honeies, will actually eat the one that has higher antibiotic activity,

which in this case helped them fight off their infection faster. So the bees are actually self-medicating. I'm picturing like they open their little honeycomb medicine cabinet and they're like, that one, please. Thank you. And how do scientists even know that bees are doing this, that they're self-medicating with honey? So that's what I want to talk to you about today. Oh, cool. The research is really picked up in the last decade or so, but now they're looking at which chemicals in honey.

And, Emily, there are a lot of them affect bee health and how. So today on the show, the chemical complexities of honey, how it helps keep honey, bees resilient to cold to pesticides, to diseases, and what role honey may play in saving the bees. I'm Emily Kwong. And I'm Burley McCoy. And you're listening to Shortwave, the Daily Science podcast from NPR. All right. Well, Burley, let's start with what is in honey that gives it these amazing medicinal

properties. I know it's got sugar and water, but what else does it have? Right, right. So when a worker bee leaves the hive to collect nectar, she stores that collected nectar in her honey crop. It's a kind of second stomach that doesn't digest the nectar. So when she brings it back to the hive, she actually regurgitates the payload to an assembly line of bees. The only way one does that, mouth to mouth, Emily. Well, I guess it's direct. What's the point of this regurgitation version of telephone? There's a point, I swear. It's partially to get rid of some of the water in the

nectar, but it also mixes in these enzymes that break down the nectar. So those enzymes lower the pH and produce hydrogen peroxide, and that helps prevent the honey from spoiling. Okay, so we've got this concoction of sugar, water, and now enzymes and hydrogen peroxide. Is that the mix that provides to be its medicine? Not quite. I saved the best for last. There's also a slew of chemicals that come from the nectar. Bernardo told me they're called phytochemicals. Fytochemicals. Fytochemicals are chemical compounds that are produced by plants. Right. Fido is just a fancy term that means plant.

Yes, yes. And Bernardo says their job is to help the plant interact with this environment. Plants use phytochemicals to deter pathogens like bacteria and fungi. They also use phytochemicals to respond to cold, stress, or to drowning in water, or to dry conditions. They also use phytochemicals as toxic compounds to deter insects, for example, and to attract pollinators like the honey bee. Deter insects, attract pollinators.

Yeah, these phytochemicals are clearly very beneficial for plants. Yeah, yeah. And in addition to being in plant nectar, they're also in pollen and in propolis, which is a kind of bee glue that bees make for their hives. And because some pollen and propolis eventually ends up in their honey, so do those phytochemicals. What are some of these phytochemicals we're talking about that shore up bee health? Like, would I recognize any of them? Well, a lot of them have pretty unfamiliar names like pecumaric acid and quercidin.

But others might ring a bell like thymal. That's an oil in the time plant and caffeine. Bees drink coffee? Not quite, not quite. They do ingest caffeine. Scientists have shown that caffeine improves sunny bee memories, but, Emily, it turns out caffeine also changes their gut microbes and makes them resistant to deadly fungal diseases. Amazing, burly. And, and...

You're not done. Mm-mm. This one floored me. Caffeine and actually a couple other phytochemicals, like the ones I mentioned earlier, just plain make bees live longer. An elixir of life. Yeah, yeah, and the list just keeps going. There is quercetin and peacomac acid. These two are not for helping the bee detoxifying insecticides, for example.

So in one study, researchers gave bees individual phytochemicals, and then they gave them pesticides. The ones that had the phytochemicals, they live longer. And Emily, some phytochemicals have even been shown to help bees. heal their wounds faster. I mean, honey really is the bees' knees. That's super cool, Burley. And on the other hand, it doesn't surprise me, because we humans have been using honey for medicinal purposes for like thousands of years. I'm thinking of like manuka honey and honey all over the world, right? Mm-hmm, and it turns out bees do that too. And they need their honey to stay healthy, which is important for us too.

Like, we rely on honeybees so much to pollinate our food. Yes, yes. Bernardo talked about that too. A lot of what we eat depends on honeybees. There are other insects that are pollinators, but honeybees are the main pollinators for tons of plants that we end up consuming as humans. I mean, I've heard one out of every three bites of our food is thanks to a pollinator. And so many crops in this country, fruits, vegetables, nuts rely on these bees for pollination to flower and to produce. Yeah. And so, Farmers will actually pay to have honeybees transported to their fields to pollinate their crops. And it's a big industry.

I mean, honeybees help pollinate billions of dollars worth of crops every single year. It's, shall we say, a crop load. It's a crop load. Okay, Burley, if bees are this important to our food cycles, people need to really get it together as far as protecting them. I know bees' numbers are declining from habitat loss and pesticide exposure and diseases. Yeah, and scientists have been telling us this for years. One of the things they've learned is that bees don't just need access to their honey to thrive. They need different varieties of honey, which they can only get if they have access to different plants. But the way our agriculture is set up now, bees don't often have access to a diversity of plants to forage. Okay. I mean, playing this out, it's like if they're pollinating a whole field of pumpkins or cabbage or something, they're only getting phytochemicals from those plants. And that's also, you're saying, bad for their health. Yeah. Another scientist actually told me having a store of different honeies in the hive is like having a stocked pharmacy. Or wouldn't you say a pharmacy? So different medicines fix different ailments, right? So a funny.

needs sunflower honey, for example, but they only have access to time honey, they're not going to thrive. Ideally, for a healthy colony, they have the variety of phytochemicals in their honey already, right? If the workers are foreign on fears with a big variety of plants and flowers, then that hive is going to be more resilient to diseases and to stresses because they're going to have more diversity of phytochemicals. I think I'm getting this. Okay, bees need to collect different kinds of nectar to make different kinds of honey or a honey blend, but they can only do this if they have access to different plants,

which is kind of hard. Yeah, yeah. And so scientists have really been advocating for increasing plant diversity around agricultural fields, for making sure bees have enough of their own honey in apiaries that, you know, harvest honey. Or one scientist even suggested bringing bees to places with more biodiversity in their off-season. Oh, like a bee wellness retreat? Yes, yeah, except they never really stop working.

And some scientists are thinking about just straight up feeding bees, phytochemicals, supplementally. Some say we're not quite there yet for being able to offer bees a kind of supermix of the phytochemicals they need, just because we don't really know how they all interact with each other. Just like you wouldn't want to mix certain medicines, right? Case in point, the two phytochemicals mentioned earlier, peak cimeric acid and quercidin, individually they make bees live longer, but together they make them die quicker. Hmm.

This seems like some tricky mixtures that we have to figure out if we're to protect bees in this way. And like many things in nature and science, it's pretty complicated. Definitely, definitely. Bernardo did tell me scientists and beekeepers are already giving their bees supplements based on individual phytochemicals. And it seems like some do help bees fight off pathogens. But again, Bernardo says the thing that will make honeybees most resilient is to make sure that they have the honey that gives them the ability to stay healthy. Because honey will have the ability,

right, if you can give that to honey, of giving more resilience to the hive. If it's made of a diversity of nectar and pollen. That would be ideal, I think, for the honeybees. I have such a new appreciation for honeybees and their beautiful liquid gold. You just can't help, but poll in love with honey. Oh, no, you didn't. No, you didn't. I did.

But seriously, thanks for bringing us this story. You're welcome. To read Burley's full story on this in Knowable magazine, check out the show notes. This episode was produced by Eva Tessfly, edited by Giselle Grayson, and fact-checked by Margaret Serino. The audio engineer was Kui-Lee. I'm Emily Kwong. Thanks for listening to Shortwave, the Daily Science podcast from NPR.