Q: About 30 years ago, I got shingles from my hip to my knee. A doctor told me to get a bottle of original Listerine and rub it on often. It took about a week or two, but the Listerine got rid of that terrible pain. I didn’t develop blisters.

A: Shingles is a painful rash that may occur many years after a person suffers chickenpox. This infection is caused by a herpes virus called varicella zoster. Antiviral drugs such as acyclovir, famciclovir or valacyclovir may speed healing if taken early enough.

Sixteen years ago, another reader shared a similar story: “What is the miracle of Listerine? Twenty years ago I got shingles. I had a blistery rash, and it really hurt.

“My doctor told me to keep rubbing Listerine on it. The itching stopped, the rash disappeared and the pain went away for good.”

We have no idea why Listerine might be helpful against shingles pain. We could find no research in the medical literature, though some doctors seem to know about this home remedy.

If you find such quirky approaches intriguing, you may be interested in our book “The People’s Pharmacy Quick & Handy Home Remedies.” Look for it in your library or at www.PeoplesPharmacy.com.

Q: I often see suggestions that certain foods could be effective against dementia. Are there any studies with results on this?

A: There is in fact some scientific data that supports a produce-rich diet to reduce dementia risk. One of the most recent was published last month in the American Journal of Clinical Nutrition (April 22, 2020). The scientists used data from a very long-running study, the Framingham Offspring Cohort. People who consumed diets with the most plant compounds called flavonoids had the lowest risk of developing Alzheimer’s disease or other dementias.

Where do you find flavonoids? Fruits and vegetables are the best sources. Americans get a lot of their flavonoids from apples, pears and oranges. Tea and cocoa are also good sources, along with blueberries, strawberries and red wine (in moderation).

Diets with lots of vegetables and fruits and very little processed food have also done well in studies of heart disease. You might recognize this as the backbone of a Mediterranean diet or the DASH (Dietary Approaches to Stop Hypertension) regimen. Both have been the subject of randomized controlled trials. So far as we can tell, both your heart and your brain will benefit if you fill your plate with colorful berries, fruits and veggies.

Q: I recently read your article about hangovers. I’ll bet you were flooded with hangover remedies. My favorite is Gatorade. Drink it after you stop drinking alcohol (before going to bed). If you are too out of it to remember to do that, drink a bottle when you wake up. I hear that Pedialyte works the same way. Of course, nothing works quite like moderation.

A: Your last suggestion is stellar. Gatorade and Pedialyte both would provide electrolytes, but a study published in BMJ Nutrition, Prevention & Health (April 30, 2020) reported that dehydration and electrolyte depletion did not appear to contribute substantially to hangover symptoms. The authors found that a solution containing extracts of ginger root, Ginkgo biloba, willow, prickly pear fruit and acerola berry was helpful, however.