Ask the Doctors

Dear Doctor: I’m in my 70s, and I work about 35 hours a week doing shipping, cleaning and light lifting. I’ve stopped visiting the gym because I’m too tired after work. My back hurts, and I’ve had heart issues recently, leaving me with a pacemaker and defibrillator. Are the 10,000 steps I walk at work each day enough exercise?

Dear Reader: The 10,000 steps you are logging each day are to be celebrated at any age. Add in a physically active job and your wish to stay connected to your work community, and we think you are making many good choices. The interactions of a workplace offer purpose and camaraderie. And the health benefits of human connection -- particularly among the elderly -- are well-documented. These include a reduced risk of cardiovascular problems, inflammatory issues and cognitive decline.

In discussing the scope and rigor of exercise with our older patients, we encourage them to listen to their bodies. They themselves are the best teachers when it comes to what types of exercise to take part in, and how much to do. Our approach is to break physical exercise into four basic categories -- endurance, resistance, flexibility and balance. In terms of plain old numbers, the American Academy of Family Physicians recommends at least 2.5 hours of moderate aerobic exercise spread out over the course of a week. This is exercise that raises the resting heart rate, such as brisk walking.

Your work, which in addition to those 10,000 daily steps has some strenuous elements, is contributing to that recommendation. However, to balance things out, you might consider adding resistance exercises, like lifting free weights. Resistance exercise helps prevent osteoporosis and frailty, builds and maintains muscle mass, improves balance and improves mood and cognition.

Flexibility exercises such as yoga or tai chi are also an important element of regular exercise, and they also help with balance. Senior and community centers often offer these and other flexibility classes targeted to older bodies. Just be sure to let the instructors know about any physical problems you have, including the back issues you mentioned in your letter.

You wrote of having heart problems in the recent past. Since you have both a pacemaker and a defibrillator, we strongly recommend that you see your primary care physician to discuss your current and any future exercise regimens. While moderate exercise with either of those devices is generally considered safe, certain adjustments may need to be made to accommodate the implanted devices.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My boyfriend laughs when I turn down the car stereo when I’m trying to find a new address, but I’ve seen his dad do the same thing when he’s changing lanes on the freeway. Why does the quiet make you feel like you can see better?

Dear Reader: Your boyfriend may have fun teasing you, but we’d be surprised if there haven’t been similar instances in his own life.

The scenarios you describe, which require you to evaluate incoming data and make split-second decisions, suck up a lot of mental energy. Researchers refer to this as “cognitive load.” Eliminating a distraction such as sound can help with concentration by reducing the cognitive load. That’s because, much like a computer, our brain’s capacity to engage in multiple tasks is finite.

To understand why, it helps to appreciate the complexities of the human brain. It’s made up of three major parts -- the cerebrum, cerebellum and brainstem. The largest and topmost part is the cerebrum, which is divided into left and right hemispheres. It deals with learning, emotions, reasoning and fine motor skills, and it interprets the flood of data from the five senses. Tucked beneath is the much smaller cerebellum, which oversees muscle movement, balance and posture. Acting as a relay center between the two and the spinal cord is the brainstem, which also oversees the staying-alive stuff we don’t think about but can’t live without. This includes breath, heartbeat, swallowing, sleep cycles and temperature control.

The three areas of the brain, plus the spinal cord, make up the central nervous system. It regulates movement, thought and emotion. It’s why you’re able to find that new address. But while it seems as though we can concentrate on multiple things at once, the brain handles tasks sequentially. It’s just making the switch so swiftly, in mere nanoseconds, that it feels like we’re multi-tasking. Once you’re hunting for a street sign, though, or gauging car lengths in fast-moving traffic, all of the collecting and interpreting of data by the central nervous system reaches critical mass. That cognitive load we talked about earlier gets to be too great. Turning down the radio removes enough incoming data to make it easier to concentrate.

A small study in Sweden looked into this phenomenon several years ago. Researchers had each of 32 participants perform an easy visual task and a challenging visual task. They were also instructed to ignore the audio -- a random sequence of sounds -- that was playing. The subsequent MRI tests revealed that when participants concentrated on a visual task, there was a decrease in the responsiveness of the auditory nerves. Basically, the brain itself was turning down the volume.

The takeaway here is that when our inner mute button can’t adequately remove the auditory distraction, our brain kicks in and we decide to turn down the car stereo. We’re adjusting our environment so the most important task -- finding the address or safely merging onto the freeway -- has a better chance of getting accomplished.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello dear readers, and welcome to the first letters column of autumn. Are we alone in wondering how summer flew by so quickly? Here at Ask the Doctors headquarters, you’ve kept our mailboxes full, so we’re diving in.

-- We got a lot of mail after a column about hemorrhoids, with writers ranging in age from a new mother in her 20s to older adults. The common theme in their advice to fellow hemorrhoid sufferers? Moisture.

A woman in her 70s, writing from Oklahoma, finds relief in the tub. “One way I've found to keep hemorrhoids from being so painful is to take warm baths,” she writes. “For me, this works much better than any medicine I have found.”

A man in South Carolina, who has struggled for decades with the maddening itch, says his doctor suggested a bidet. “I ordered one that attaches to the toilet for about $40,” he writes. “I have not had any itching since, so it’s worth a try!”

-- A reader with dentures wonders about the potential health effects of the adhesive that keeps the devices in place. “I sometimes have to use the adhesive twice a day in order to eat meals, or else I wind up biting the insides of my bottom lip,” she writes. “Is daily ingestion of denture adhesive harmful?”

Some denture adhesives contain zinc, a mineral that our bodies need for good health. However, an excess of zinc over time can cause health problems, including nerve damage, often in the hands and feet. There have been some reports of zinc toxicity among denture wearers, but in those cases the person used two or more tubes of a zinc-based adhesive per week. According to product instructions, a single tube is meant to last seven to eight weeks.

In this particular case, it’s possible that the dentures no longer fit properly, which can happen due to bone shrinkage. We recommend seeing your dentist. Your existing dentures may need to be relined, or you may need to be fitted for new ones.

-- In response to a column about Lyme disease, a reader asks whether tests have improved since 1996, the year she had a run-in with a deer tick. The answer is yes, today’s tests are more accurate. However, it takes several weeks for antibodies to Lyme disease bacteria to develop, so it’s possible to get a false negative if one is tested too soon. It takes four to six weeks after infection for the Lyme test to show an accurate positive result.

-- We’ll close with a thought from a reader in Pennsylvania who thought something was missing in a recent column about mindfulness and meditation:

“As a former geriatric nurse, I have often seen patients calmed by prayer, a Bible reading and a Scripture quote as they face a serious operation or death,” she wrote. “I think this deserves to be mentioned in reference to the calming and beneficial effect it promotes.”

As always, thank you for your thoughts, kind words and ideas. We look forward to hearing from you, and will see you for another letters column next month.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)