DR. WALLACE: My grandma reads a lot of magazines, newspapers and books on various topics. She then likes to give me advice on subjects she's recently learned something new about.

Well, guess what she just came up with? The other day, Granny told me that she read somewhere that you can grow new brain cells and that I should do everything in my power to make my body be in the right condition for this to happen. Is that true that I can add more and more brain cells?

If so, I sure wish I had started a bit sooner, since I've always been roughly a C+ student in school. — Sign Me Up for More Brains, via email

SIGN ME UP: Your brain has control over your muscles — directing you to know how to hit a ball, play the piano or open up a box. Research shows that when you exercise, your muscles take charge. When you're active, they send chemical signals telling your brain, "It's time to grow." Physical activity has multiple brain benefits, encouraging the birth and growth of new brain cells and the extension of blood vessels that supply oxygen and sugar to brain cells.

Regular exercise boosts levels of brain-derived chemicals that are responsible for new brain cells. After a few months of workouts, people who exercise regularly often see improved memory and usually perform much better on various memory tests.

In contrast, without regular exercise, the neurons might be less likely to make new connections with other brain cells.

At any age, exercise makes you feel more alert and have an easier time remembering things; so yes, I'll side with your smart granny on this one and I'll encourage you to exercise regularly. I'm sure you, granny and I would all like to see you earning regular B's in school with an occasional "A" tossed in as well, so please give serious consideration to regular physical activity.

I CLEAN MY DOLLARS

DR. WALLACE: I'm kind of paranoid about money being dirty even going to the 7-Eleven convenience store and getting change after I buy my snacks. The clerk gives me money back that has been handled by other people all day, and this sure gives me a big blast of anxiety.

During this pandemic, my fears have gotten so bad that I've been washing my money in the washing machine at home with my clothes. Sometimes the bills fade a bit, and I was wondering if my washing them might change the authenticity of the paper bills? — Fear of Currency, via email

FEAR OF CURRENCY: Putting a dollar or other bills in the washing machine will probably not ruin it. The Bureau of Engraving and Printing likely completed many tests to ensure this wouldn't happen.

Generally, if you forget a bill in a pocket and it goes through the washing machine and dryer, it works out OK. However, it might eventually damage the security features.

I do have a suggestion for you. First of all, after you touch cash, wash your hands before touching your face. Secondly, perhaps you could look into using a prepaid debit card to make your future purchases so that you won't have to handle cash at least until this terrible pandemic finally subsides. Experts say that catching COVID-19 from currency is quite unlikely, but I understand and respect your fears nonetheless.

Dr. Robert Wallace welcomes questions from readers. Although he is unable to reply to all of them individually, he will answer as many as possible in this column. Email him at [email protected]. To find out more about Dr. Robert Wallace and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

Photo credit: geralt at Pixabay