Ask the Doctors

Dear Doctors: I take medication for Type 2 diabetes. I also enjoy horehound candy. I recently ate three candies after taking my medication and experienced a sharp drop in blood sugar. Afterwards, I read that white horehound is attributed to lowering blood sugar. Do you know if this is true?

Dear Reader: White horehound is the common name for a flowering herb in the mint family. Its use as a candy flavoring, and also as a medicinal aide, dates back to ancient Egypt. Often referred to simply as horehound, the botanical name is Marrubium vulgare, a mix of Latin and Hebrew. Vulgare means common in Latin, and Marrubium is believed to derive from the Hebrew words for bitter juice. Botanists suspect the “hore” portion of the name may come from the white fuzz that covers the stems of the plant, which looks like hoarfrost. And just to clear up any possible confusion, there is a plant in the same family known as black horehound. Its botanical name is Ballota nigra. However, it is not the plant you are asking about.

Horehound is quite fragrant, with a pungent and bitter flavor. It is also highly bioactive. Thanks to its complex chemical composition, the herb has antioxidant, anti-inflammatory, expectorant and antimicrobial properties. It has been used to thin mucus secretions in the respiratory tract, stimulate appetite, reduce gas and bloating, manage swelling, ease breathing and help fight off topical and parasitic infections. If you read the labels of cough syrups and lozenges that advertise themselves as an expectorant, you may find horehound in some of the ingredient lists.

More recently, research has begun to look at the possible effects of horehound on blood glucose. A study conducted in 2012 that investigated that question yielded mixed results. But subsequent reviews of the data suggest the herb may, in fact, lead to a drop in blood glucose. The researchers pointed out the inherent difficulties in assessing herbal products, which contain a wide array of bioactive ingredients. They suggested that, by broadening the scope of the analysis of the data, an effect on blood sugar could be seen.

A definitive answer regarding how white horehound may affect blood sugar levels requires further study. However, the initial data, along with a body of anecdotal evidence, suggest that the herb may, indeed, have a hypoglycemic effect. That means people like yourself, who are living with Type 2 diabetes, should be aware of that possibility. Medications for Type 2 diabetes work to lower blood sugar. Using a product that contains white horehound, whether it is a candy or a cough syrup or lozenge, may complicate blood sugar control.

We think it would be wise for you to reach out to your health care provider and tell them of your experience with the horehound candy. If they are not familiar with this potential side effect of the herb, ask them to research it. It is possible you will receive guidance for a safe way to indulge in the treat. But you should also be prepared for the idea that you will have to limit horehound candy, or possibly eliminate it from your diet.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I suffered extensive fatigue that I had attributed to a COVID-19 infection. Then a lung culture found something called mycobacterium avium complex. Would you kindly consider discussing this? I realize it’s not a common illness, but for that reason it can go undetected and undiagnosed.

Dear Reader: Mycobacterium avium complex refers to a group of bacteria that are naturally present in the soil, water and dust all around us. Also known as MAC, these microbes are harmless to the majority of people. But when someone is living with a chronic lung disease or a weakened immune system, inhaling the bacteria can lead to an infection. When this occurs, it is known as MAC lung disease. Unlike tuberculosis, which is also a bacterial lung infection, MAC lung disease is not contagious.

MAC lung disease can affect the lungs in two different ways. One, known as nodular bronchiectatic, causes tiny knots to develop within the smaller airways and air sacs of the lungs. Over time, the resulting inflammation leads to scarring in the tissues of the lungs. This makes it difficult to naturally clear mucus, which, in turn, increases the risk of developing a respiratory infection. The other, more aggressive form of MAC is known as fibrocavitary disease. This is when damage to the lung tissue leads to the development of pits, or even holes, in the lung tissue.

Symptoms of both forms of MAC lung disease include the pervasive fatigue that you experienced. This is due to the extra work your body is doing to try to fight off the infection, and to the damage to the lung tissue itself. Additional symptoms can include a chronic cough that can be dry or may produce mucus; shortness of breath; a sensation of heaviness or pain in the chest or lungs; a low-grade fever that is not associated with another illness; unintentional weight loss; a decrease in appetite; and night sweats. If coughing brings up mucus or sputum, it is possible that it may be tinged with blood.

Diagnosis begins with a physical exam, a medical history and a detailed description of symptoms. When MAC lung disease is suspected, sputum cultures can identify the presence of bacteria. These bacteria are common, so repeated cultures may be required to confirm a persistent infection. Scans, such as a CT or an X-ray, can reveal physical changes to the lungs. A bronchoscopy, which uses a flexible scope to examine the lungs, can confirm a diagnosis.

Treatment depends on each person’s specific symptoms, current physical health and medical history. When symptoms are mild, the condition may be closely monitored but not actively treated. This is known as watchful waiting. Some people are prescribed therapies to help clear mucus -- and bacteria -- from the lungs. When needed, antibiotics are prescribed. This therapy often lasts for a year or more. And due to the challenges of antibiotic resistance, it typically requires the use of multiple antibiotics.

To ease symptoms, your doctor has likely urged to you to eat a healthful diet, avoid tobacco, do breathing exercises and get vaccinated for flu and COVID-19. We hope you follow through.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello, dear readers, and welcome to the monthly letters column. We are well into the third month of the new year, and for some of us -- the data say it’s probably most of us -- the resolutions we made on Jan. 1 have already fallen by the wayside. We have been hearing from readers asking for encouragement, and have also had readers sharing tips that are helping them stay on course. We’ll have a resolution reset column coming soon. And now, onward to the mail.

-- A column about how research shows the gut microbiome gradually recovers after the use of antibiotics has caused a reader a bit of confusion. “This column says that probiotics can delay recovery after antibiotics, but it also says taking fermented foods with live cultures is helpful,” he wrote. “Are these live cultures not considered probiotics? Please clarify what is meant by ‘probiotics.’”

When you take antibiotics, both the pathogen that made you sick and the beneficial bacteria living in the gut are killed off. After treatment, it takes a month or two for the microbial colonies of the gut microbiome to be restored. Probiotic supplements, which you can buy at drug and grocery stores, and fermented foods both contain probiotics. However, supplements contain high amounts of a limited variety of microbes, and because the gut is basically a clean slate after antibiotic treatment, taking a supplement can lead to an off-balance colonization of the gut. Researchers have found that this actually slows down the natural recolonization of the gut. Fermented foods also contain probiotics, but in a wider variety and smaller numbers. Eating them creates a gentler and more natural path to recolonizing the gut with your unique microbial profile.

-- We get a lot of letters about toenail fungus, a common infection that is notoriously difficult to cure. We recently heard from a reader who has been struggling with it for several months. “Last fall, I started getting a yellow and crumbling nail on the big toe of my right foot. I used Vicks VapoRub every day and soaked with tea tree oil, and it went away,” he wrote. “About a month after I stopped treating it, the yellow color started coming back. Why did that happen?”

Unfortunately, the scenario described is quite common. It is possible to manage a toenail fungus infection with topical treatments so that the appearance of the nail improves or even returns to normal. However, the chances the infection has been eradicated are small. Topical treatments can’t adequately penetrate the tough nail to completely kill off the fungus. Oral anti-fungal medications, while more effective, are not always completely successful. If you do wish to try that route, your doctor can prescribe the medication, explain the possible side effects and guide you through the treatment.

We are hearing from a lot of new readers, so it’s time for a reminder that we can’t look at medical records, comment on medications or treatments or offer a second opinion. And, as always, thank you for your letters. We love hearing from you.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)