DEAR DR. ROACH: I’m a 75-year-old man. I keep my cellphone in my left shirt pocket every day. Recently, my left nipple has become very sore. I asked my general physician about it, and he wasn’t concerned. I’m concerned that the electromagnetic field from the phone may be an issue. Is there any research on this, and should I have this checked more carefully? — T.W.

ANSWER: Your physician was correct. Cellphones cannot produce frequencies with enough energy to damage tissues. It’s much more likely that the mechanical rubbing of the phone on your chest is causing the soreness. Just ask marathon runners, both men and women, about nipple soreness. It’s often called “runner’s nipple.” (There are specialized products to protect the nipple, or they use good ol’ bandages over the nipple while running. It’s all mechanical, even with a soft shirt.)

Put your phone in a different place, not because of the electromagnetic field but to keep it from rubbing against you.

DEAR DR. ROACH: My dentist recommends chewing gum after each meal to help clean my teeth. Most gum contains aspartame, xylitol and other chemicals. Do you think this is a good idea? — J.S.

ANSWER: Your best bet to clean your teeth after meals is brushing and flossing your teeth. But if you can’t do this, sugar-free chewing gum does get rid of food particles, stimulates saliva flow, reduces bacteria, and reduces the risk of cavities from as low as 8% to as high as 40%.

Aspartame and xylitol are artificial sweeteners that don’t promote tooth decay. Xylitol in particular helps stop the growth of bacteria. Aspartame is one of the most studied chemicals ever, and the small amounts of it in chewing gum have almost no health risks. Sugar alcohols like xylitol and mannitol can cause diarrhea in sensitive people when taken in high-enough doses, but this is usually due to sugar-free (“diet”) beverages, cookies or pastries.

Remember that everything you eat, drink, touch or breathe is made of chemicals. Even if they have long or difficult-to-pronounce names, they still may be helpful or even necessary for your health and well-being if taken the right way at the right dose and concentration.

DEAR DR. ROACH: I am a 72-year-old male who was diagnosed with Type 2 diabetes about 30 years ago. I’ve been insulin-dependent for about 20 years now. I also have benign prostatic hyperplasia, and four months ago, I had a prostatic artery embolization. Prior to the procedure, I was catheterized for four months while awaiting an appointment with an interventional radiologist. The procedure seems to have improved my urinary symptoms.

However, since the procedure and the removal of the catheter, I’ve experienced incontinence and must now wear overnight protective underwear at bedtime. Over the past year, my urologist has tried several medications like finasteride, vibegron and trospium, but nothing has worked to reduce my nighttime incontinence. Are there other treatments or therapies I could pursue to improve my nighttime incontinence? — J.B.

ANSWER: Incontinence after a prolonged catheterization is very common. Your urologist has tried three common classes of medication. Vibegron is a beta-3 agonist, and trospium is an antimuscarininc agent; both are used for overactive bladders. Finasteride reduces prostate size over the span of months.

Your urologist has much more information than I do, and you need to go back and ask them this very question. However, I also recommend that you ask them about pelvic floor muscle training and bladder-training exercises, as these are important components of treatment for post-catheter incontinence that you haven’t mentioned trying. Biofeedback and electrical stimulation are additional options.