Supporting Peak Immunity for Respiratory Health

An interview with Roger Seheult:

Roger Seheult, MD, is a pulmonologist and sleep specialist at Beaver Medical Group in Banning, California. He is certified in internal medicine, pulmonary diseases, critical care medicine, and sleep medicine through the American Board of Internal Medicine. He is also an associate clinical professor at the University of California, Riverside School of Medicine and an assistant clinical professor at the School of Medicine and Allied Health at Loma Linda University.

Dr. Seheult has a passion for demystifying complex medical concepts. He is the cofounder of MedCram, an online medical education platform.[End bio]

Some of the most common health struggles during the fall and winter months involve immune and pulmonary health. Consequently, many people take a greater interest in being proactive about their health at this time of year. Healthcare practitioners can assist these patients by making recommendations based on the strongest research and science.

In this interview with Element Senior Writer Sarah Cook, ND, Roger Seheult, MD, discusses studies focused on nutrition in relation to pulmonary and immune health. You’ll also learn what pivotal moment caused this conventionally trained physician to take an interest in natural and integrative healthcare options.

SARAH COOK: As a physician with four board certifications, what does clinical practice look like for you?

ROGER SEHEULT: The combination of being a critical care physician, pulmonologist, and sleep doctor essentially amounts to my clinical life being set to repeat on a three-week cycle. The first week is all critical care in the intensive care unit (ICU). The second week is in the clinic, seeing patients who have problems with their lungs, like chronic obstructive pulmonary disease (COPD), asthma, pulmonary nodules, etc. I also see patients with sleep apnea. The third week is dedicated to reading sleep studies. I look at the studies to determine which patients have sleep apnea or other sleep disorders.

COOK: Could you tell me more about your work with MedCram?

SEHEULT: It all started because I teach and supervise physician assistant students at Loma Linda University. Every month or so, we get a new set of students. One of my students suggested I offer teaching on a YouTube channel. It made a lot of sense because I found myself repeating the same concepts with each new round of students. The other thing that made sense about recording my lessons was that my students could watch the fundamentals, and then we could build upon that on clinical rotations. Now, the YouTube channel and the MedCram website has grown to more than 700,000 subscribers. Our goal has always been to teach other clinicians, but the videos explain things in such a simple way that we’ve also attracted a following of educated laypeople who want to understand their conditions or treatments better.

COOK: With your conventional medical background, how did you become interested in nutrition?

SEHEULT: It’s a very deep question. Six months ago, I never would’ve imagined I’d be speaking with you about nutrition, but when I dug into the research, what I found really opened my eyes.

I’m a sleep doctor and had no idea there was evidence that getting seven to eight hours of sleep or more per day reduced your chances of getting the common cold. That research came out of the University of Pittsburgh in 2015. I also had never known that getting a good night’s sleep could improve your response to the influenza vaccine.

I began to see that there are potentially a lot of things that might support immune function without side effects—like getting outside in nature or eating berries.

It gets a bit philosophical, but I started to look at how we managed infectious disease 100 years ago, before penicillin and other antibiotics. This was the era of John Harvey Kellogg. There were sanitariums where people received hydrotherapy and got fresh air. I found journal articles reporting that people in the sanitariums had lower mortality rates from the flu than those in the army hospitals.

I started to explore the world of nutrition and supplementation and was impressed with what I’ve found. The gold standard for making recommendations in medicine is the randomized, controlled trial, but until we have that, we may as well focus on improving nutrition and use substances that are accessible and low-risk—as long as they have a potential for benefit.

COOK: Are there supplements you recommend?

SEHEULT: I can tell you the supplements I’ve decided to take because of my research. I don’t recommend these as prevention or treatment, but merely to help ensure the immune system is at the top of its game.

The supplements I’m taking are vitamin D, vitamin C, n-acetylcysteine (NAC), quercetin, and zinc. I also get plenty of sleep, get outside in nature, and take an alternating hot-and-cold shower every day after work.

COOK: Let’s talk about some of the reasons behind taking these supplements. Why does vitamin D make the list?

SEHEULT: Vitamin D is one of the most difficult vitamins to explain because its actions are so diverse. Really, it’s a fat-soluble hormone that’s able to pass into cells and directly affect the transcription of DNA. Vitamin D supports the production of antimicrobial peptides in the respiratory epithelium and also promotes a healthy inflammatory response.

A recent study out of Ireland, The Irish Longitudinal Study on Ageing (TILDA), showed vitamin D supplementation could support upper respiratory health. The lead researcher, Professor Rose Anne Kenny, says that even though we don’t have data from a randomized, controlled trial, this is strong circumstantial evidence. She is a world health expert who highly recommends that all adults should supplement with vitamin D daily.

There was also a 2017 meta-analysis in the British Medical Journal, which asked whether vitamin D could support upper-respiratory tract health. The answer was yes. There were two important findings from that analysis. First was that vitamin D is best taken daily rather than as a weekly or monthly bolus. Second was that even modest amounts (as little as 200 IU, or 5 mcg, per day) could help.

The key with vitamin D is taking enough, but not too much. It’s rare to reach toxic levels but theoretically possible. You should always measure serum levels of vitamin D and supplement until they’re optimized.

COOK: What about vitamin C?

SEHEULT: Most of the data we have about vitamin C relates to intravenous vitamin C (IVC) used in the ICU setting.

Dr. Paul Marik’s group at the Eastern Virginia Medical School showed that IVC is potentially helpful in septic shock. There is also some interesting data on IVC from the CITRIS-ALI Study. A 2019 meta-analysis in Nutrients reported that IVC might shorten the length of stay in the ICU.

We have less data on oral vitamin C, but we know it’s an important water-soluble antioxidant. I take it as a supplement and also eat a big bowl of fruit every morning for the naturally occurring vitamin C.

COOK: You also mentioned NAC. What are some of its mechanisms?

SEHEULT: NAC works mainly because, as a reducing agent, it replenishes glutathione. It’s the antioxidant effect that helps to reduce total oxidative stress, and support detoxification and immune health.

Of course, glutathione is only one of many antioxidant systems in the body. NAC also supports superoxide dismutase, which requires manganese, copper, and zinc. There’s also the xanthine oxidase system and the glucose-6-hydrogenase system. The more we can do to support these systems, like eating berries and fruits, the better.

There’s also another important mechanism of NAC. its chemical ability to break the disulfide bonds of crosslinked mucus gels. It turns out this mechanism also translates to an ability for NAC to support healthy hemostasis and healthy circulation.

COOK: The last nutrients on your list are quercetin and zinc. Tell me more about them.

SEHEULT: Quercetin and zinc go hand in hand because of early in vitro data..

Zinc is ionic and can’t penetrate across cell membranes. It can only enter through a specific channel, called a zinc ionophore.

We have great data from the test tube to show this. When you put cells in a high concentration of zinc, nothing happens. But when you put the cells in with zinc and an ionophore, zinc enters the cells.

As it turns out, quercetin is a zinc ionophore. Quercetin is naturally occurring in onions, capers, and other vegetables. I also take it as a supplement.

I take a zinc supplement, but no more than 40 mg of elemental zinc daily. The risk in taking too much zinc is that it can drop your copper levels, so you need to be cognizant of that.

COOK: Do you have any final thoughts about using supplements for immune support?

SEHEULT: I have one word of caution. Even the most benign substance is not inert. We’ve seen that with grapefruit juice, which interacts with countless medications. Vitamins and minerals might interact with each other or with medications. Always check for nutrient-drug interactions whenever making any recommendations for supplementation.