Colds vs. sinusitis; treating back pain; artificial sweeteners and cancer: Upstate Medical University's HealthLink on Air for Sunday, April 23, 2023
Ear, nose and throat specialist Mark Arnold, MD, discusses sinusitis, colds and allergies. Physical therapist Steven Lounsbury, DPT, explains how physical therapy can help back pain. Rheumatology chief Andras Perl, MD, PhD, shares research linking some artificial sweeteners to liver cancer.
Host Amber Smith: Coming up next on Upstate's "HealthLink on Air," an ear, nose and throat doctor helps differentiate a cold from sinusitis.
Mark Arnold, MD: ... About 15% of us get diagnosed with an acute sinus infection every year. It's also the most common reason we get antibiotics prescribed for us in the United States. ...
Host Amber Smith: A physical therapist has some advice for people suffering from back pain.
Steven Lounsbury, DPT: ... The best kind of treatment for it is to stay active, to stay mobile. Our spines are made to move, and we feel better with movement. I often teach my patients the phrase that 'movement is medicine.' ...
Host Amber Smith: And a physician scientist shares how his research team determined that artificial sweeteners can cause liver cancer.
Andras Perl, MD, PhD: ... I personally have not used sugar alcohols, not, at least, knowingly. But I believe that people should cut this out of their diet now. ...
Host Amber Smith: All that, and a visit from The Healing Muse, coming up after the news.
This is Upstate Medical University's "HealthLink on Air," your chance to explore health, science and medicine with the experts from Central New York's only academic medical center. I'm your host, Amber Smith.
On this week's show, we'll hear how physical therapy can relieve back pain. Then we'll learn the science behind the artificial sweetener/liver cancer connection. But first, an ear, nose and throat doctor tells how sinusitis is diagnosed and treated.
From Upstate Medical University in Syracuse, New York, I'm Amber Smith. This is "HealthLink on Air."
Especially at the change of seasons, people may start feeling their sinuses -- or is it a cold? Sometimes it's not so easy to tell. Here to explain is Dr. Mark Arnold. He's an assistant professor of otolaryngology and communication sciences at Upstate.
Welcome to "HealthLink on Air," Dr. Arnold.
Mark Arnold, MD: Thank you so much for having me.
Host Amber Smith: How common is sinusitis?
Mark Arnold, MD: Sinusitis is really an inflammation or an infection of the sinuses that line our nasal cavity. And I think it's important we first make the distinction between acute and chronic sinusitis. They both have symptoms of nasal congestion, facial pressure or pain, and discharge, and sometimes a lack of sense of smell.
But acute sinusitis may be a virus or a bacterial infection that lasts for four weeks or less, while chronic sinusitis are symptoms that last for three months or longer. Both of these conditions are very common.
About 15% of us get diagnosed with an acute sinus infection every year. It's also the most common reason we get antibiotics prescribed for us in the United States.
Chronic sinusitis is also common, about 15% of us. And while it's not as common as things like hay fever or allergic rhinitis, it is actually a little bit more common than things like asthma.
Host Amber Smith: So if you get an acute sinusitis every spring, say, and it happens every spring, repeatedly, that's still considered acute?
It doesn't become chronic just because you seem to always get it every spring?
Mark Arnold, MD: So, if the symptoms are about four weeks or less, most commonly they last between one and two weeks, it's still considered an acute sinus infection if your symptoms resolve between infections, which is important.
But certainly, as you're alluding to, certain times of the year, we may be more prone to get sinus infections. If things like our allergies flare, or we're exposed to certain outdoor pathogens, we may notice that sometimes we get them more commonly at certain times of the year than others.
Host Amber Smith: Are men and women affected equally? And do you see any racial disparities in who's affected by sinusitis?
Mark Arnold, MD: Sinusitis, both acute and chronic, affects really everyone throughout social demographics, as well as men and women, as well as people of every race. We do find that women tend to be more affected as far, as symptomatology goes, by their sinus problems, but still men and women are equally affected.
And as far as people of different races, again, everyone is affected. Certainly there are differences in treatment outcomes, as well as access to treatment. People who are African American actually account for about 12% of the U.S. population and the same rate of chronic sinusitis, yet only about 5% of those people end up undergoing surgery for this disease, so there are certainly disparities that we notice, but again, everyone's affected.
Host Amber Smith: Is sinusitis contagious from person to person?
Mark Arnold, MD: In the heightened sense of the COVID-19 pandemic, we're always worried about things being contagious. And while an upper respiratory infection certainly has a time period where it can be contagious, where we may or may not be coughing and having fevers, that portion of it certainly can be contagious.
But as far as for many people with chronic sinusitis, they've certainly cleared their infection but still having symptoms, and at that point, they're not really contagious anymore, although people may think they're contagious.
Host Amber Smith: Well, let me ask you to go over the symptoms.
What are the symptoms of sinusitis?
Mark Arnold, MD: So again, we characterize acute sinusitis by symptoms that are four weeks or less, and then chronic sinusitis with symptoms that are 12 weeks or longer. The symptoms really are a nasal discharge, which can be clear, may be purulent or mucusy, as well as nasal obstruction or congestion, kind of that feeling of stuffiness, which is pretty unique to our sinuses and face, and also, potentially, a lack of sense of smell and fullness or pressure or pain in the sinuses.
Host Amber Smith: What about fever?
Mark Arnold, MD: So, fever can happen with certain types of acute sinusitis. Most times, acute sinusitis, I would say 90% to 95% of the time, are actually caused by a virus. So we still get those symptoms, and we most often don't have a fever.
Sometimes, we can get a really bad sinus infection with severe symptoms, severe pain, maybe a change in discharge, maybe a double worsening, where your sinuses were acting up and now they've gotten even worse. Those kinds of people may have a bacterial infection in their sinuses, and those people we tend to think may have something like a fever, but I would say most cases of both acute and chronic sinusitis, they may actually never end up having a fever.
But a good question.
Host Amber Smith: Are there health conditions that make sinusitis more likely?
Mark Arnold, MD: Most patients that I see with both acute and chronic sinusitis don't have an underlying condition, but there certainly are some that make sinusitis more likely. Patients with asthma, for example. We think of our upper airways and our lower airways as being part of the same system, so certainly patients with asthma more likely have inflammation of their lower airways. Similarly, patients with asthma are more likely to have chronic sinusitis, so this makes sense. In addition, patients with allergies, they may have a higher incidence of sinusitis in that they're being triggered.
Also, people with immune system problems or immune deficiencies, they certainly don't have the ability to fight sinus infections, so they get them more often.
And then finally, there are patients with conditions like cystic fibrosis. That's a problem with the lining of the sinuses, as well as a lining of the lower airways.
And they have small little cilia (hairlike projections) that help clear out mucus, and if there are problems underlying that, they can be prone to sinus infections as well.
Host Amber Smith: This is Upstate's "HealthLink on Air," with your host, Amber Smith. I'm talking with Dr. Mark Arnold. He's an assistant professor of otolaryngology and communication sciences at Upstate.
I'm curious about how sinusitis is diagnosed and how you, as a physician, go about telling the difference between a bad cold and a sinus infection. Or maybe, I guess, a person could have both at the same time, right?
Mark Arnold, MD: Exactly. You know, the symptoms of a cold and sinusitis can be similar, but there are some distinctions that we can make to help us distinguish the two. Colds typically last just a week or two, while sinus infections tend to be longer. They may have this period of worsening, where their symptoms of congestion, pressure and drainage just get worse. People often say their symptoms started out with a cold, but then they may go on to develop a sinus infection. Similarly, the discharge with a cold may be clear, but a sinus infection, you may have thick nasal discharge that's yellow or green.
Finally, facial pressure or fullness we think is kind of more distinct with a sinus infection ... a cold, you know, if you have a cough and otherwise not feeling well, but the real facial pressure, we think, is distinct to the sinuses.
Host Amber Smith: At what point might a person be referred from their primary doctor to a specialist like yourself?
Mark Arnold, MD: I see a variety of patients, with all sorts of sinus complaints, from mild to severe, but patients who have sinus symptoms that aren't resolving with just over-the-counter treatments or home remedies, and those that have a significant disruption in their daily lives due to their sinus symptoms, I think are great patients to be referred to myself or another otolaryngologist.
As symptoms last for more than a few months, despite treatments like antibiotics or medical therapies, it could represent a chronic sinusitis, so that's also an indication to see an otolaryngologist.
And also repeat sinus infections: Again, it's common for us to have one or two sinus infections a year, depending on the person, but if you're having three, four, five, I think it should be time to see an otolaryngologist as well.
And finally, I think any patient who has nasal polyps, those represent kind of a severe inflammation in the sinuses.
I think all of those people should be evaluated by an otolaryngologist. They could be polyps, they could be something else.
So that would be some times to see one.
Host Amber Smith: How would you like people to prepare for a visit with an otolaryngologist? Are there particular questions that you would be asking them that they need to be prepared to answer?
Mark Arnold, MD: So, the most important part of a visit with an otolaryngologist or myself in detailing chronic sinusitis is a detailed record of their path: when their symptoms started, what kind of treatments they've been on, such as nasal saline, topical steroids or antibiotics, and how their symptoms have changed throughout their treatment course. In addition, a detailed sinus history is important. If they've undergone any CT scans, bringing those discs or images with them to the visit, as well as any surgeries that they've had in their past.
All of those things, and their additional questions regarding their sinusitis, can make for a productive visit.
Host Amber Smith: Well, let's talk about treatment options, and I know it's going to differ depending on the cause and the individual person. But in general, if you remove polyps, or if you straighten a deviated septum, for instance, is that meant to eliminate sinusitis?
Mark Arnold, MD: I get this daily from patients, you know? Eliminating sinusitis is a long-term career goal of mine, but it really depends on the patient's cause of their underlying sinusitis as well as their response to treatment. For some patients, we can completely eliminate chronic sinusitis. They're free of all their symptoms. They're no longer on, really, any medical treatment, any sprays or any topical nasal steroids or antibiotics.
Yet others truly have a chronic condition that really is refractory or resistant to everything we try, including surgery and expensive medications. Their sinuses may continue to be inflamed, their sinuses may kind of close off, and their polyps may grow back.
But yet my goal is to see them along their treatment journey, improve their quality of life, get their lives back with reducing their sinus symptoms. And I would say for most patients we're able to achieve this. And certainly we work hard to do it.
Host Amber Smith: And for those who have allergies, can you or have you been able to, see a reduction of symptoms if that person gets their allergies under control?
Mark Arnold, MD: I do treat both allergies and sinusitis. I do try and make a distinction between the two because their treatment paths are a little bit different. And while their symptoms, especially nasal congestion, overlap, I think treating their allergies is a good starting point because that can help reduce their triggers.
They can help reduce their both acute and chronic sinus symptoms.
Host Amber Smith: I'm curious about whether sinusitis, if it's not treated, does it ever develop into something more dangerous?
Mark Arnold, MD: With certain types of acute sinusitis, if they do have severe symptoms, those can go on to develop problems with their sinuses.
Our sinuses are located between our eyes and underneath our brain.
Very rarely, can we have infections that spread to the eyes or infections that spread to the brain. Those are a surgical emergency and often those abscesses and infections need to be treated and drained. Again, most of the time though, sinusitis resolves on its own, even without antibiotic treatment.
But if there are severe symptoms like we discussed, a fever, a double worsening of symptoms, that's certainly an indication to get antibiotic treatment.
Host Amber Smith: Is there anything a person can do to reduce their overall risk of getting sinusitis? If we anticipate the seasonal changes, and we know that we tend to get sinusitis when the seasons change, can we get ahead of that and try to stop it from happening?
Mark Arnold, MD: There's not a lot that we know about what causes us to develop chronic sinusitis, so it's somewhat hard to know exactly how to prevent it. However, there are certain things we can do that might help and should honestly be practiced for our overall health. The first and foremost would be: Stop smoking. It's probably the best recommendation I can give to decrease sinonasal (the nose and sinus area) inflammation overall.
If you know your allergens, things you're allergic to, and triggers to your sinusitis, certainly that can be helpful.
When you are sick, rest, taking in plenty of fluids, managing stress when you can. Oftentimes I see patients who get a flare of their symptoms when they're under a particular period of stress, and it's maybe their immune system isn't quite functioning right, so I think that's helpful.
And like we discussed before, I think prompt treatment of a severe sinus infection is helpful. This includes topical nasal saline sprays, topical nasal steroid sprays, as well as an antibiotic if symptoms are lasting longer than 10 days, or if those symptoms are pretty severe.
Host Amber Smith: Are there home remedies that you recommend to patients once they have got sinusitis going on?
Mark Arnold, MD: The best treatment is time, initially, as most of these infections get better within a couple weeks, but there are several things we can do at home. Like I discussed, saline rinses can help remove mucus in the nose, help wash away things that are causing inflammation.
Many patients like to inhale steam or have a humidifier nearby that can help open things up. Certainly a warm shower can make us feel better, warm compresses. And of course, staying hydrated, getting rest and avoiding any irritants that we know that may be causing our symptoms to get worse.
Host Amber Smith: Well, Dr. Arnold, I appreciate you making time for this interview. Thank you.
Mark Arnold, MD: Thank you for having me.
Host Amber Smith: My guest has been Upstate assistant professor of otolaryngology and communication sciences Dr. Mark Arnold.
I'm Amber Smith for Upstate's "HealthLink on Air."
Physical therapy might help relieve your back pain -- next, on Upstate's "HealthLink on Air."
From Upstate Medical University in Syracuse, New York. I'm Amber Smith. This is "HealthLink on Air".
If you've injured your back and all you want to do is rest, you might be doing the wrong thing. Today I'll talk about physical therapy treatment for low back pain with someone from Upstate who specializes in strength and conditioning. Steve Lounsbury is a doctor of physical therapy.
Welcome to "HealthLink on Air," Dr. Lounsbury.
Steven Lounsbury, DPT: Thank you very much. Thank you for having me.
Host Amber Smith: If someone strains their back or feels like they've pulled a muscle and it hurts to move or bend, what would you tell them to do?
Steven Lounsbury, DPT: I would say in the case of an acute injury -- in our world, that's usually within the first two weeks -- the best kind of treatment for it is to stay active, to stay mobile. Our spines are made to move, and we feel better with movement. I often teach my patients the phrase that "movement is medicine."
Host Amber Smith: So even if it hurts, you still have to stay somewhat mobile. Do you recommend ice or heat for the pain?
Steven Lounsbury, DPT: Typically in the acute phase, that early zero to two weeks, I tend to tell people that there is an inflammatory process going on, that inflammation that usually follows an injury, so ice tends to feel better.
However, once we're out of that early period, whichever one feels better for their particular symptoms is what I go with. There is no strong evidence either direction after that acute phase.
Host Amber Smith: Are there different recommendations for children versus adults versus senior citizens?
Steven Lounsbury, DPT: Not necessarily. What we base our treatment guidelines on are actually called clinical practice guidelines, and there are a set of documents that our governing body has developed over decades of research.
They're continuously being updated. And they develop them with the concepts in mind of treating across the lifespan. And we focus less on the age group affected by the injury and more specifically about the stage of injury they're in, that acute versus chronic stage.
Host Amber Smith: Is there a difference between if it's lower back versus mid back or upper back?
Steven Lounsbury, DPT: There is slight differences in the way we approach treatment. However, the generic concepts remain the same for how we approach movement, encouraging mobility or the ability to move through different ranges of motion, as well as strengthening of all the supportive muscles around the affected area.
Host Amber Smith: So what happens if someone doesn't heed this advice, and they decide they're going to rest anyway because they're in pain and they're going to lay on the sofa until they start feeling better? Are they making things worse for themselves? Are they dragging it out?
Steven Lounsbury, DPT: I wouldn't say the term "making it worse," so much as delaying their recovery. Typically when we have periods of immobility or not moving around, we tend to feel worse anyway. Again, our spines are made for movement. We feel better when we change postures throughout the day when we do different activities throughout the day.
There is such a thing as overdoing it in the acute phase, but more often than not, light activity such as walking or light household work is perfectly fine.
Host Amber Smith: How does a person know if they need to see a doctor about an injury?
Steven Lounsbury, DPT: So as a broader concept, it's tough to identify when you need to seek care, whether from your primary care physician or directly from a physical therapist. I would usually tell people if it is something that is not changing in the level of severity or how intense the pain is or the symptoms are for about one week of time, it might be time to consider that consultation with one of your doctors or a physical therapist.
Host Amber Smith: So let's talk about what role physical therapy can play in treating acute back pain. Would you ideally want to see a patient soon after the injury, or do you want them to wait and see if things get better or if they change without intervention?
Steven Lounsbury, DPT: So I would actually prefer to see the individual or the patient as soon as possible after an injury, for several reasons. One, because in those clinical practice guidelines I mentioned earlier, we do have a lot of good evidence for treatment techniques early on in the injury and recovery process.
And secondly, because the injury likely occurred for some underlying reason, whether it was improper lifting technique or weakness in target muscles that we would rather are stronger can take the load away from the spine, there's usually that underlying cause that we can help to address to prevent this from happening again.
Host Amber Smith: For someone who's never had PT, what can they expect?
Steven Lounsbury, DPT: So physical therapy is not a one-size-fits-all generic treatment. There is no magic pill to it. Every physical therapy session that you would receive through somewhere like Upstate is led by a licensed doctor of physical therapy. . We are a doctorate level profession who goes through a long course of schooling, across a wide domain of different specialties and ways of assessing different systems.
And when you come see a doctor of physical therapy, our treatments involve many different approaches. It's called a multimodal approach. So sometime there is heat, or sometimes there's hands on mobilization or manipulation of the spine or the joints. There's a lot of therapeutic exercise, which is targeted strengthening and stretching of the muscles in the area of the injury.
And quite often what we also look at is not only the immediately affected area, but also adjacent areas or areas near to the injury, because we operate on this concept that one area affects the next one. It's that old song, "The head bone's connected to the neck bone." It's just a lot more complicated than that.
Host Amber Smith: So if a person wants to see a physical therapist, they don't necessarily have to ask their primary care provider. They can just call the physical therapist directly, is that right?
Steven Lounsbury, DPT: In New York State, we operate under a term called direct access, which means that a patient can just walk in from the street and see a doctor of physical therapy for either 30 days or 10 treatment visits, whichever occurs first before they're required to have a script or a referral from their primary care doctor or an orthopedic doctor.
Unfortunately, at Upstate we are unable to do that, per our accrediting body guidelines. We do require that script or referral.
Host Amber Smith: This is Upstate's "HealthLink on Air" with your host, Amber Smith. I'm talking with Dr. Steve Lounsbury. He's a doctor of physical therapy specializing in strength and conditioning, and we're talking about the role of physical therapy to treat low back pain.
Is everyone a candidate for physical therapy, or is there any person who would not be a good candidate for physical therapy?
Steven Lounsbury, DPT: That's a good question to bring up and a good moment to talk about what we would call red flags in the medical community. These are signs or symptoms that might suggest you need further medical assessment rather than treatment from a physical therapist.
They might suggest some more serious underlying pathology or other condition that might be explaining why your back pain is persistent. And those could be multiple. We won't dive into all of them today. But the red flags that I'm usually looking for is something more systemic, like fevers and chills, a change in sensation in the region of your groin, what we usually call a saddle area, if you were sitting on the saddle of a horse, any kind of sudden unexplained weight loss recently, especially if it was unintentional, pain at nighttime or at rest that does not change with a change in position, a failure to improve over the course of about one month, and there are many more. We could keep going for a while. But there are certain red flags like that that would say to either your primary care doctor or if you are being seen by a physical therapist, we're trained to recognize those to say, PT might not be the most effective treatment at this moment, and you should seek further medical attention.
Host Amber Smith: So it sounds like you look at like the whole patient, not just where their pain is, but you look at them as a whole person and try to figure out what else might be going on.
Steven Lounsbury, DPT: Absolutely.
Host Amber Smith: So are the exercises that you prescribe, are they meant to relieve the pain or prevent further injury?
Steven Lounsbury, DPT: Yes, to both. And the approach to treatment changes slightly depending on the individual patient in front of you. And I think this is where the nuance of what physical therapy is as an art and a science kind of meets in the middle to say that if we've had pain for only a couple of weeks, my goal is to help you get completely out of that pain, to eliminate it entirely, and then to prevent it recurring in the future or happening again.
However, if this is something that's been going on for a couple of decades, you've lived with chronic back pain for 20 plus years, we know per all the research that we've done that the pain is unlikely to ever go away entirely at that point. There are changes in the brain that mean you're more sensitive to that pain now, and it's likely to be lasting.
But what we can do is take you from, let's use our typical numeric rating scale of zero to 10, 10 being the worst pain you've ever felt, and zero being no problem. If I have a patient who's had 20-plus years of back pain and they come in at an eight out of 10, well, I would see success if we could bring them down to a 2 or 3 out of 10, knowing that the pain is still there, but we've given them ways to manage that on their own and be more active, accomplish what they might want to do.
Host Amber Smith: So when a person comes for physical therapy, they're going to be active, right? I'm just wondering, do they need to dress like they're going to a gym?
Steven Lounsbury, DPT: Yes. That is typically something that we do run into on occasion. We know it is tough because quite often you are coming to physical therapy from work or from picking up your kids or from anything else. It does make it harder, depending on, especially if we're looking at your low back, if you're wearing clothing that doesn't allow us access to at least visualize your low back or see it, and we are pretty good about draping with towels and stuff like that to maintain a patient's modesty, of course. But it is nice to have exercise clothes. It allows you greater freedom of movement.
So for men, if you're wearing a dress shirt that's tucked in very tightly, it might be tough to assess how far you can truly move if the shirt is what's limiting you. For females, showing up with either a skirt on or leggings or jeans that might restrict your movement of your lower legs, that might also be an issue. Because like I mentioned, when we look at the low spine, we're also considering the role of the hips, the knees, the feet, and how they play into that.
Host Amber Smith: So for someone with an acute pain injury, how soon might they expect to notice improvement?
Steven Lounsbury, DPT: There are a couple different ways of noticing improvement. One, in terms of pain relief. Hopefully we can achieve something within a session, especially if it is that acute. Most of our treatment that we apply, especially for acute injuries, is focused on quick reduction of that pain. We don't want to let it become something chronic or disabling for the long term. We want to try and get you out of that moment of pain and discomfort as soon as possible. So hopefully within the first session or two, they would start to realize that there is some pain relief.
Building strength takes a little bit longer. That's a matter of weeks as we go. Usually, I would like to tell patients that a clinically meaningful change in their strength -- meaning something they'll notice the difference in their daily life, not just something we could measure with a tool here --will take on average, about six weeks to start to be noticeable to the patient. It is a slow initial curve, and then it speeds up over time.
Host Amber Smith: So your relationship with a patient might last a period of weeks or months typically, is that right?
Steven Lounsbury, DPT: Correct.
Host Amber Smith: Well, we've been talking mostly about acute pain from recent injuries, but you did mention, people with chronic pain. Can they still get some relief? Have you seen that work for people through physical therapy?
Steven Lounsbury, DPT: I certainly have. We have quite a large percentage of our treatment caseload that we see that is chronic back pain. In fact, one of the leading causes of disability worldwide is chronic back pain. It's the six month costly condition in the US.
And one of those things that we try to do, like I mentioned earlier, is focus on not only relieving some amount of pain, but finding ways for them to manage it throughout their day. Some of that might be setting reminders on their phone to be up and be moving for a certain period of time if they sit for work. It might be teaching exercises to maintain mobility every morning, every evening, because if we think about sleep as the longest period of inactivity in our day. Where we're largely in the same position, that's when most people feel worse. It's late at night and first thing at the morning.
Host Amber Smith: Oh, that's a good point. I wanted to ask you about massage. Have you ever seen that helping someone with acute back pain?
Steven Lounsbury, DPT: I certainly have, and it's actually one of those recommended interventions we have within our clinical practice guidelines. We are not massage therapists. That is a separate profession. However, we can utilize soft tissue massage or soft tissue manipulation. It is skills that most physical therapists have been trained in rather extensively. Everybody entering the field has some amount of training in it. You can go on to do continuing education within that area as well. So it is typically one of those treatments we'll apply early on for an acute injury.
Host Amber Smith: Are there stretches or movements that you would recommend that people can do regularly to strengthen their backs and then hopefully prevent injury in the first place?
Steven Lounsbury, DPT: There is no particular movement because it is so patient specific. Speaking in a generic sense, trying to get out of the forward bent posture that most of us spend the day in typing, writing, driving, cooking, cleaning, everything is largely in front of our body. I made a joke when I had a community presentation last night that we don't often dice an onion or fold laundry behind our back. So most of us spend the day very forward and rounded with our shoulders. Our chin creeps forward. So working on bringing ourselves up out of that position helps to relieve some of the back pain that comes just from being in one position for too long.
Host Amber Smith: Well, that's really good to know. Thank you so much for making time for this interview, Dr. Lounsbury.
Steven Lounsbury, DPT: Thank you very much for having me.
Host Amber Smith: My guest has been doctor of physical therapy, Steven Lounsbury from Upstate Medical University. I'm Amber Smith for Upstate's "HealthLink on Air."
Next on Upstate's "HealthLink on Air," how artificial sweeteners can cause liver cancer.
From Upstate Medical University in Syracuse, New York, I'm Amber Smith. This is "HealthLink on Air." Commonly used sweeteners can cause cancer of the liver, according to research conducted recently at Upstate. I'm talking with the lead author of that study, Dr. Andras Perl. He's a SUNY (State University of New York) Distinguished Professor and also the division chief of rheumatology at Upstate. Welcome to "HealthLink on Air," Dr. Perl.
Andras Perl, MD, PhD: Thank you Amber. It's nice to be with you.
Host Amber Smith: You and your colleagues published your research in the journal Nature Metabolism, and I wonder what the response has been like from other scientists. Is this the first paper to show that sugar substitutes can cause liver cancer?
Andras Perl, MD, PhD: This is the first paper, and we were, ourselves, surprised how effectively we could block the development of cancer by eliminating the sugar from the blood and other tissues of these mice. But this also has relevance for human subjects.
Host Amber Smith: Have scientists suspected this connection for a while, and have they been looking for proof of this, or is this something brand new?
Andras Perl, MD, PhD: This is brand new. I have been suspecting this for a long time, and we uncovered many, many years ago that these sugar alcohols accumulate in mice and human subjects that lack this enzyme. And we uncovered that this human subject developed liver disease.
First, we found it in mice, that 50% of mice that lacked the enzyme had liver cancer. And subsequently, human subjects, mainly children, were found to develop a very aggressive liver tumors who had this enzyme deficiency, but nobody directly linked the accumulation of the sugar alcohols to cancer.
We also uncovered another enzyme called aldose reductase is highly overexpressed. We did know that aldose reductase generates the alcohol from the sugars that accumulate in the absence of transaldolase. So we published a paper on the subject that transaldolase deficient mice developed liver cancer in 2009, which was 14 years ago. And in this paper we showed that sugar alcohols accumulate in these mice, and this other enzyme, aldose reductase, is also overproduced in the mice. And later on, human subjects were found that also lacked transaldolase and developed liver cancer, but they were unsure whether the accumulation of the alcohols was actually driving the cancer.
We suspected that the overactivity of another enzyme was contributing to the accumulation of the sugar alcohols. So then, to find out whether this other enzyme contributed to the development of cancer, we generated mice that lacked both enzymes, both aldose reductase and transaldolase, and those mice did not develop cancer, and they did not accumulate sugar alcohols.
So this other enzyme, aldose reductase, converts the sugars that accumulate in the absence of transaldolase. The other enzyme converts them to sugar alcohol, and that apparently is highly carcinogenic. That's what we discovered in mice, but this also applies to humans because humans who lack transaldolase also accumulate these sugar alcohols to the same degree as mice do.
Host Amber Smith: I want to ask you some more specific questions about your work, but when a finding like this comes out and is published in a prestigious journal like this, do scientists congratulate one another, or are you more competitive?
Andras Perl, MD, PhD: That's a good question. I did get a few congratulations, but not too many, but maybe others expected this to happen, or I don't know what they think. The question is actually interesting.
Host Amber Smith: Well, please tell us more about how your study was designed. What sweeteners did you focus on?
Andras Perl, MD, PhD: We did not focus on sweeteners specifically. We knew that these alcohols accumulated in these mice. And, we suspected that the generation of the alcohols was mediated by the other enzyme aldose reductase, which was over-produced.
And we thought that these, the accumulation of the sugar alcohols contribute to the disease, but we didn't know if it was contributing to the cirrhosis that prevents cancer or it was also contributing to cancer. We only found this out when aldose reductase was inactivated, and the mice no longer made the alcohols and they no longer developed cancer.
So that indicated to us that these alcohols actually, the sugar alcohols, induced cancer. Subsequently, we also treated cells in vitro cancer cells, and we found that they highly over-proliferate if you treat them with sugar alcohols in vitro. So the sugar alcohols themselves induced cancer cell proliferation. We also used inhibitors of aldose reductase, not just genetically inactivated it, but treated cancer cells with drugs that can inhibit this enzyme and they inhibit the proliferation of cancer cells.
So we do know that not only genetic inactivation of the enzyme can prevent cancer, but very, very likely inhibiting the enzyme with drugs can also inhibit cancer formation.
Host Amber Smith: So these two enzymes that you keep mentioning -- the transaldolase and the aldose reductase -- do healthy people have both of these enzymes in ample supply?
Andras Perl, MD, PhD: Yes. Normal people have both of these enzymes in ample supply, and one can imagine that through the generation of sugar alcohols, aldose reductase could contribute to cancer formation.
On the other hand, transaldolase protects from cancer, so individuals who lack transaldolase develop liver cirrhosis and cancer. So this enzyme protects from liver disease.
And we also uncover that this enzyme also protects from Tylenol-induced liver failure, which is the leading cause of acute liver failure in humans. We found in another study that people who develop liver failure due to Tylenol overdose, a great percentage of them lack transaldolase, at least, one allele of the enzyme is mutated in those individuals. So this enzyme deficiency also predisposes to Tylenol-induced liver failure, and inactivation of aldose reductase also protects from Tylenol-induced liver failure in mice. So we can presume that in human subjects who develop liver failure due to Tylenol overdose, inhibiting aldose reductase may also be helpful.
Host Amber Smith: This is Upstate's "Health link on Air," with your host Amber Smith. I'm talking with physician scientist Dr. Andras Perl. He's a SUNY Distinguished Professor who led research recently showing how an ingredient in sweeteners can cause liver cancer.
So what do these sugar alcohols do that leads to cancer of the liver? And I know that it involves the enzyme as well.
Andras Perl, MD, PhD: So sugar alcohols, we don't know exactly how they cause cancer, to answer your question flatly, but we have some suspicions what they might do.
Sugar alcohols create osmotic pressure in the cell. When the cells are exposed to alcohols rather than sugars, they cannot be metabolized, not as readily as sugars, and the alcohols themselves cause osmotic pressure that turn on genes that mediate cell proliferation.
So one of these genes are called "junk," or JNK. So these genes promote DNA replication and cancer proliferation. So I think the osmotic pressure that they create is what drives carcinogenesis. This is a very crude answer, and much more details need to be discovered.
Host Amber Smith: Would this only be a concern in the case of that JNK gene?
Andras Perl, MD, PhD: So this "junk" gene, or JNK, is involved in most cancers. So it is possible that activation of these genes, through osmotic pressure, contributes to many forms of cancer. In fact, in our paper we showed that inhibiting aldose reductase also blocks the proliferation of breast cancer cells. So this mechanism of enhanced carcinogenesis by sugar alcohols may not be limited to liver cancer.
Our model was limited to liver cancer, but this mechanism may apply to other forms of carcinogenesis.
Host Amber Smith: And the sugar alcohols we're talking about are found in sorbitol and erythritol?
Andras Perl, MD, PhD: So sorbitol and erythritol are sugar alcohols, and these accumulate in the absence of transaldolase. There is one additional alcohol that we detected highly, which is highly accumulated, called sedoheptulose, which means that it has seven carbons that make up the sugar. Carbon is coal. The main ingredient of coal is carbon. That's an atom. And the sedoheptulose has seven. The sorbitol molecule has six carbons. Erythritol has four carbons. And these carbons are actually formulated in our body by a pathway called the pentose phosphate pathway. And that's where these two enzymes are functioning in our body. The aldose reductase and the transaldolase are a part of this pathway that generates sugars that contain various numbers of carbon atoms. So the erythritol, which is used as a sweetener very commonly, or sorbitol, have four or six carbons.
Host Amber Smith: So these sweeteners, which are on the market and are in different products now, do you think the FDA (Food and Drug Administration) needs to reconsider whether these products containing these should be sold?
Andras Perl, MD, PhD: Absolutely. So the reason that they found them to be safe is that they cannot be detected in normal individuals. But they have not been measured in a tumor environment, so nobody knows to what degree they are available in tumor environment. And from our study, it's very clear that a very high level of them drives cancer.
Whether or not consuming these sugar alcohols can achieve that concentration anywhere in our human body is a matter of further discovery. It's unknown whether these concentrations that we detected in our transaldolase-deficient mice can occur in human beings who just consume these sweeteners. But, one can assume if somebody has a predisposition, that will be greatly enhanced by consuming these alcohols. So whoever is drinking these sugar alcohols is taking on a greater risk of cancer development.
Host Amber Smith: Well, compared with artificial sweeteners, does regular sugar, does that pose a threat to the liver the same way?
Andras Perl, MD, PhD: The quick answer is yes. It turns out that sugars, especially refined sugars like glucose, for example, support cell proliferation in a much more robust and potentially toxic way than other carbohydrates or, for example, fat.
Fat can be burned much more effectively through mitochondria than sugars, which tend to preferentially go into glycolysis, which is, a pathway more commonly used by cancer cells. Sugars in general are not healthy, and they support -- at least in the liver -- potentially abnormal growth.
On the other hand, we do need sugar for the brain to work. Our brain cells depend on sugar. That's the main source of energy for brain cells. So, deprivation of humans from sugar or sources of sugar is probably not something that we should aim for. But limiting sugar might be helpful in general, especially thinking about liver cancer.
Host Amber Smith: Now your work on this particular study was done in laboratory mice, so I wonder is it going to be replicated in humans at some point?
Andras Perl, MD, PhD: Some of some aspects of this work has been conducted in humans. So, others have measured the sugar alcohols in patients who lack transaldolase, and they highly accumulate. They also accumulate in human subjects who develop liver cancer and lack transaldolase. So very clearly this is present in subjects who have liver cancer and transaldolase deficiency.
Nobody has studied the expression of aldose reductase in these individuals. However, aldose reductase is known to be overexpressed in all kinds of liver cancers, including those where transaldolase is not deficient.
So the overexpression of aldose reductase is very clearly a driver of liver cancer outside the deficiency of transaldolase. So inhibiting aldose reductase could be a very general mechanism of blocking liver cancer in general. And if we believe that that inhibits cancer, the mechanism of that involves diminished production of super alcohols.
So I must say that sugar alcohols drive liver cancer in general, probably outside transaldolase deficiency.
Host Amber Smith: After seeing these results, have you and your colleagues removed things from your diet that contain added sweeteners?
Andras Perl, MD, PhD: Actually, one of my technicians in the lab -- his name is Joshua Lewis, and he greatly contributed to this work because he is genotyping these mice -- told me last week that he actually tried to lose weight. He actually is relying on sugar alcohols. And he has many friends that he's chatting with on the internet, and they use sugar alcohols for achieving weight control, which may work at this potential cost. So I believe that he will be removing this from his diet.
I personally have not used sugar alcohols, not, at least, knowingly. But I believe that people should cut this out of their diet now.
Well, Dr. Perl, thank you so much for making time for sharing this with us.
Thank you so much for having me, Amber. Thank you.
Host Amber Smith: My guest has been Dr. Andras Perl. He's a SUNY Distinguished Professor and the division chief of rheumatology at Upstate. He also teaches and does research in biochemistry and molecular biology and microbiology and immunology. I'm Amber Smith for Upstate's "Health Link on Air."
And now, Deirdre Neilen, editor of Upstate Medical University's literary and visual arts journal, The Healing Muse, with this week's selection.
Deirdre Neilen, PhD: Grief comes to us all and never in just one guise. Clare Bercot Zwerling is a poet in Texas. Here is one version of grief she calls "The Waiting."
After you left
my arms lost their power
the space between shoulder and hand
was all air
I couldn't drive
or push a shopping cart
or comb my hair
but I held the baby extra tight
The shriek that ruled my insides
flung me outdoors
away from the beehives of
from laughter and frivolous talk
from music stuck as I was
to that train raging down my track
no tears no roar no prayer
no breath held or given
no sinking to the knees
could bring you back
In the evenings I lay
curled beneath a thin blanket of night
waiting for that distant light
of everything absent
waiting for the angel
to spread her comfort --
this is why
and this is why
Donna L. Emerson, who lives and writes in both New York and California, sends us another version of grief, no less powerful.
Here is "In the Blue Room."
Wound tight and tired, he sat us down
around his Formica kitchen table,
as if for a meeting of his board:
ready to announce his funeral plans.
He spoke with such authority
I almost didn't register the sheer white terror
behind his glassy blue eyes.
Then, tucking him in after his first surgery,
alone in that blue-cold room, no nurse nearby,
he whispered, fingers reaching my wrist,
I think I'm going to beat this thing, honey!
The doctor would tell him the next day
what he had just told me,
of the oat cell cancer
and three months to live.
But Dad's boy-hope bloomed like a balloon
that glowing night
bouncing about his room for the last time.
Dad, it's good to see you happy.
We'll take this one step at a time.
We squeezed hands. I'd never tucked
my father into bed before. I folded each
corner, the way he taught me, military style,
pulled the cloth as high as it could go,
firm against his big chest, lingering over cotton.
Host Amber Smith: This has been Upstate's "HealthLink on Air," brought to you each week by Upstate Medical University in Syracuse, New York. Next week on "HealthLink on Air," rates of eating disorders are soaring among adolescents.
If you missed any of today's show or for more information on a variety of health, science and medical topics, visit our website at healthlinkonair.org.
Upstate's "HealthLink on Air" is produced by Jim Howe with sound engineering by Bill Broeckel.
This is your host, Amber Smith, thanking you for listening.