AUGUSTA, Ga. (WJBF) – The COVID-19 pandemic has spurred a massive amount of research in the medical community. From transmission to prevention to effects, researchers have been kept busy trying to understand the virus. One area of research that may surprise you, though, is the impact on taste. Many COVID patients report a loss of taste after battling the virus, but the question is, “why?” That is where the Medical College of Georgia at Augusta University has stepped in, and Dr. Lynnette McCluskey is helping to lead the way. She’s a neurobiologist and a taste researcher among many other hats she wears at the Medical College.
Brad Means: Dr. McCluskey, thanks for what you’re doing, and thanks for being here.
Dr. Lynnette McCluskey: My pleasure, Brad.
Brad Means: All right, so I mentioned that people have either lost their taste with COVID or they know somebody who has, what’s the percentage do you know, how many folks when they get sick lose taste?
Dr. Lynnette McCluskey: We have really wide ranging reports in the literature anywhere from about 30% to 80%. And what we don’t know, if that’s changing over time with the different variants, but over half of people report lost tastes.
Brad Means: How long does it stay gone? I know a guy in the newsroom here at Channels 6 who still can’t smell, I think, and his taste is limited. How long does it stay with you?
Dr. Lynnette McCluskey: For most people it’s transient. It returns within a few weeks, but for the unfortunate few up to 30% of patients, 40%, maybe, experience long term taste lost. And we have patients that have gone over a year now without taste. So this is a big problem.
Brad Means: Are we pulling out of the pandemic? I mentioned that as well. Is it time to feel like we’re leaving it in the rear view mirror? What are you seeing at the college in the hospital?
Dr. Lynnette McCluskey: Well, I think we’re cautious. Everybody is eager to get back to normal, certainly scientists and physicians feel that as well. But I think we still have some caution as we look what’s happening in Western Europe.
Brad Means: Yeah.
Dr. Lynnette McCluskey: Usually tells us what we can expect. So, I think we need to be careful, but certainly there’s some return to normality.
Brad Means: All right, so let’s take a look at this research that you and your team are doing over at MCG when it comes to taste bud. So am I correct in assuming that you are trying to figure out among other things, why the coronavirus attacks the taste buds?
Dr. Lynnette McCluskey: Exactly. So, we know almost nothing about how that happens. What’s the biology between this taste lost? And it took some time at the beginning of the pandemic, just for people to accept that this was real taste loss and it was unprecedented to have over half of a patient population with no taste whatsoever. So, yeah, this is ongoing research, but certainly we’re behind even what we understand about smell.
Brad Means: So many times when we’ve talked to y’all about studies that you’re doing, you have volunteers that have come forward. Are any actual humans taking part in this, people who’ve had taste loss or still have it?
Dr. Lynnette McCluskey: Yeah, my grant is strictly based on animal studies.
Brad Means: Got it.
Dr. Lynnette McCluskey: But Dr. Hess and Dr. Rotkowski are very actively studying taste loss and smell loss in patients.
Brad Means: So what are y’all using, mice?
Dr. Lynnette McCluskey: We do use mice.
Brad Means: And did you genetically re-engineer one to make it have human characteristics? Kinda walk me through that.
Dr. Lynnette McCluskey: Yeah, so that’s fortunate to have Dr. Lynn Gann, my collaborator on the grant. He’s one of the best mouse geneticists in the world.
Brad Means: Yeah, he loves the CRISPR.
Dr. Lynnette McCluskey: Yes.
Brad Means: And how do work it.
Dr. Lynnette McCluskey: He’s an expert at CRISPR.
Brad Means: Yeah.
Dr. Lynnette McCluskey: So he was able to create several new mouse models for us to be able to study taste loss. And one, mice don’t get sick with coronavirus. Their receptor is just a little bit different in binding the virus. So Dr. Gann was able to genetically engineer a mouse to express the human form of the receptor for the coronavirus. And we’ll be looking at that in taste buds and how that affects taste function.
Brad Means: Well, I know that we’re just getting started here, but have you found anything out with this humanized mouse that kind of makes the light bulb go on for the research? I didn’t know it did that.
Dr. Lynnette McCluskey: Yeah, I mean, anything we find will be an addition to the research community, because we know nothing about how this coronavirus receptor, the ACE2 receptor, we don’t know how this affects taste function at all. It’s really been understudied. So, we have some hints, very early hints that when we record from nerves that innovate the tongue and put taste solutions on the tongue, that there’s a difference in that humanized mouse, especially to certain types of stimuli.
Brad Means: What are you feeding the mouse and how can you tell if it can taste it or not?
Dr. Lynnette McCluskey: Yeah, there are ways to do behavioral research to look at mouse taste and get a readout. We’re looking at neural impulses.
Brad Means: Okay.
Dr. Lynnette McCluskey: Coming from those taste buds, so.
Brad Means: What’s that mean? Go ahead, you give it something sour, it does something?
Dr. Lynnette McCluskey: Yeah, so we’re recording from a nerve, and if we put something sour on the tongue, we can look at how that nerve responds and measure that. And if taste is affected with inflammation as we’re testing, we may see that we don’t get taste responses to salt, sugar, sour.
Brad Means: I respect that you said we don’t know anything at this point. And as a researcher, I know that took a lot of courage to say, so I’m not trying to presume that you do know a lot at this point, but I do wanna ask you if, you know if it’s possible for COVID to target only certain taste buds, and maybe you could still partially taste?
Dr. Lynnette McCluskey: Yeah, that’s a great question, Brad. People are looking at that and that’s one of the things we’ll be doing in our grant, looking at which types of taste cells in the taste bud have the receptor for the virus. And so there’s a very small human study suggesting that the cells for sweet and bitter are affected by the virus.
Brad Means: When I think of the coronavirus, COVID 19, I think of it attacking the lungs because so many people had breathing issues. Does it target other organs? Tell us about that.
Dr. Lynnette McCluskey: Yeah, the receptor for the virus is very widespread throughout the body. It actually serves normally as a break, things like inflammation and blood pressure. So, as with many viruses, the coronavirus hijacked that receptor to get into cells. And the way that the receptors expressed all over the body really is the reason behind this multiorgan problem within some COVID patients.
Brad Means: Do you have any idea, any hope when it comes to how long this research project is going to take? Is it until the grant runs out? When can we know some concrete things?
Dr. Lynnette McCluskey: Certainly within a year.
Brad Means: Yeah.
Dr. Lynnette McCluskey: This grant just started. So we should have some results out in a year. It’s a two year grant, but really for the field, I think will be finding answers to these questions for the next four or five years. I think we’ll have some answers within a year, but it will be ongoing for sure.
Brad Means: And so what’s the goal here. If coronavirus, goodness forbid, comes back in full force, maybe you can let people keep their taste.
Dr. Lynnette McCluskey: Yeah, that’s the goal or for people that have long term taste loss, which is really debilitating, people are depressed, they can’t enjoy a meal with their friends.
Brad Means: Right.
Dr. Lynnette McCluskey: Nutrition problems show up. So, the goal is really first of all, to be able to treat those people with long term taste loss, there’s something for smell loss that’s validated, known as smell training. And so you would go through, you would have some odorant say in bottles and retrain basically your olfactory system to smell again. So, you’d have a bottle of rose oil, maybe some coffee, and just go through those each day, several times. And it’s supposed to rewire your olfactory system, get those connections back again after the damage. And so, we don’t know at all, if something similar is available to help patients with taste loss, but that’s the goal to treat them.
Brad Means: You hit on something so important, nutrition, because if you can’t taste, you lose interest in eating, it impacts your overall wellbeing. What kind of advice would you give to folks like that? Who just say, it’s not worth eating anymore, I don’t enjoy it.
Dr. Lynnette McCluskey: Yeah, it’s a problem, we’ve known that for years, people that are undergoing radiation or chemotherapy for cancer have taste loss, and that’s because the taste buds are turning over, cycling throughout life. So they’re affected just like the cancer cells. And people with aging, their taste changes. So, usually the advice is, first of all, not to over salt your food. A lot of people tend to put more salt trying to bring back flavor.
Brad Means: Right, that’s what you do.
Dr. Lynnette McCluskey: Yeah.
Brad Means: But it’s not, you shouldn’t.
Dr. Lynnette McCluskey: Right, and that can lead to its own problems, but trying to vary the texture, the temperature of food. And that’s hard, sometimes the neurons in the mouth, on the tongue, that sense those things are also affected by COVID. So for example, adding spicy foods can sometimes make your sense of taste a little zippier.
Brad Means: Yeah.
Dr. Lynnette McCluskey: But some people lose that as well. So, really just trying to get maybe even an ensure shake, something to that, where you’re getting that nutrition in your body.
Brad Means: Your research is so fascinating and you are sort of just pioneering this new frontier and finding out new information, it seems almost daily. Is this capturing the interest of med students? Are you seeing the doctors of the future kind of gravitate toward what you and Dr. Gann are doing and saying, “No, I want to do that as well.”
Dr. Lynnette McCluskey: We have had increased attention to our work.
Brad Means: Yeah.
Dr. Lynnette McCluskey: Which it’s really highlighted the chemical senses as we call them taste and smell, and it’s brought a lot of new trainees to the field, which I think is great because it should stimulate new findings for many years to come. An unfortunate silver lining out of this terrible past two years.
Brad Means: Boy, let me just ask you this one more question, tap into your knowledge as a taste researcher, kind of off the COVID thing for one second, before we have to take our first break, and it’s, how long does it take to lose a taste for a food? If you’re trying to lose weight, all right, and a lot of our viewers are, and you’re addicted to Doritos or Oreos or something like that. How long do you have to stay away from that food before your body no longer craves it.
Dr. Lynnette McCluskey: That’s a really complicated and tough question.
Brad Means: Right, I’ve tried.
Dr. Lynnette McCluskey: But I wish I had the answer to that.
Brad Means: Yeah, but I mean, it’s possible isn’t it, to put a type of food in your mouth that your taste buds used to love and you don’t like it anymore. Isn’t that possible?
Dr. Lynnette McCluskey: It is, and a lot of that has to do with higher brain centers.
Brad Means: Yeah.
Dr. Lynnette McCluskey: So training the cortical areas in your brain, really we’re learning that tastes, especially sugar, lights up reward areas in the brain, and it’s very much like a drug addiction.
Brad Means: It is sugar is like a drug.
Dr. Lynnette McCluskey: Yes, absolutely. So, it’s retraining your whole behavior. Some of that we can get at in the taste buds, but it really takes the whole circuit from tongue to brain.
Brad Means: Well, Dr. McCluskey, thank you for the research that you and Dr. Gann and the team over there are doing. We appreciate it, we hope it leads to great things, and congratulations on the grant.
Dr. Lynnette McCluskey: Thank you so much, thank you for having me.
Brad Means: Absolutely, Dr. Lynnette McCluskey, Medical College of Georgia at Augusta University. They’ve been on the leading edge of COVID research since this pandemic started and they continue to do that.