Dear Doctor: My husband and I are pretty strict about screen time with our kids. I read about a new study that indicates that screen time actually changes a child’s brain. Is this true? How much screen time is OK?

Dear Reader: As parents ourselves, we share your struggle when it comes to limiting screen time. But considering how we adults often struggle to put down the phone or step away from the computer, it’s not surprising that our kids face the same challenges.

Screens are so instantly absorbing, it’s all too easy to hand a fussy baby or toddler a phone while juggling several other tasks. And with so much social interaction now shifted to the online world, tweens and teens can feel cut off from their peers without screen access. Add in the increasing amount of schoolwork now done on computers and online, and it can feel like a screen-centric life is all but inevitable.

A recent study supports a growing body of research that suggests it’s time to rethink our acceptance of screens. Published last November in the journal JAMA Pediatrics, it found a link between screen time and a drop in language and literacy skills among young children. Not only that, brain scans found that kids who spent a lot of time in front of a screen experienced certain changes to the physical structures of their brains.

The researchers began by assessing the cognitive abilities of 47 children between the ages of 3 and 5. They also gathered detailed information about screen habits from the children’s parents. MRI scans of the children’s brains revealed that those who exceeded the recommended one hour of screen time per day had lower levels of development and organization in brain tissues known as white matter. White matter is made up of long nerve fibers surrounded by fatty protective tissues, and it plays a key role in language development and cognitive skills.

The children with higher screen time and structural brain changes also had poorer outcomes on tests measuring language and literacy skills. This all sounds dire, so it’s important to note that this was a small study with a narrow scope. The authors noted that the question of screen time for children deserves further study.

As for how much screen time is OK, that’s the big question right now. According to updated guidelines from the American Academy of Pediatrics, children younger than 18 months should have no screen time at all, other than video chatting with parental supervision. For children between ages 2 and 5, the AAP recommends a maximum of one hour of high-quality programming per day, watched with a parent present to explain what they are seeing. After age 6, the advice is consistent limits that maximize physical and mental health, as well as face time with family and friends.

It’s important that as parents, we lead by example and step away from our own screens.

(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: Our grandfather won’t use his hearing aid because he doesn’t like how it makes things sound. However, I recently read that using a hearing aid reduces the risk of dementia. How can we get him to use one?

Dear Reader: Your grandfather isn’t alone in his reluctance to use a hearing aid. Many people with hearing loss wait as long as 10 years before finally agreeing to seek help. Meanwhile, poor hearing hinders their ability to communicate and interact with family, friends and the world at large. This leads to isolation and depression, and as a growing body of research shows, also increases the risk of cognitive decline.

A study published in the Journal of the American Geriatrics Society last fall found that when older adults with hearing loss used a hearing aid within three years of their diagnosis, they had measurably better outcomes in several important health categories than those who didn’t correct their hearing. Those who used a hearing aid had lower rates of dementia and depression, as well as fewer injuries due to falls.

The researchers examined eight years of insurance data for almost 115,000 women and men over age 66 who were diagnosed with hearing loss. They found that the risk of a dementia diagnosis, including Alzheimer’s disease, was 18% lower among the hearing aid users. The risk of becoming injured in a fall dropped 11%, and the risk of depression was also 11% lower. Their findings are consistent with previous research that established a clear connection between even mild uncorrected hearing loss and an increased risk of dementia and depression.

The next step in the research is to pinpoint how and why uncorrected hearing loss is tied to dementia and cognitive decline. One theory is that hearing loss leads to structural changes in the brain, which in turn affect memory. Another ties it to the profound social isolation that hearing loss can cause.

Meanwhile, your efforts to persuade your grandfather to use a hearing aid aren’t unusual. The insurance data used in the study revealed that, among those diagnosed with hearing loss, an average of only 12% went on to get hearing aids.

We think it’s encouraging that your grandfather already owns a device. He has shown himself to be open to improving his hearing and may just need a bit of help to get on the right track. Try talking to him about what, specifically, he doesn’t like about his current hearing aid. Then if you have the time, do some research about the current technology and offer to help find a replacement.

Shopping for a hearing aid can be confusing and, with hearing loss, daunting. There are several types, with different fits and placements. Be sure your grandfather is using a reputable audiologist who can help him to find the perfect device. It’s possible that with ongoing support, your grandfather may be willing to give hearing aids another try.

(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: What’s the difference between a cold and the flu, and how do you know which one you’ve got? Why can’t antibiotics help?

Dear Reader: Whether it’s a cold or the flu, the reason you are feeling awful is because you’ve been infected by a virus. More than 200 different types of viruses can cause a cold, and the most common is the rhinovirus, the culprit behind up to half of all colds. The flu, as its name suggests, is caused by the influenza virus. Of the four known types of influenza virus, labeled A, B, C and D, the seasonal epidemics we prepare for each winter are caused by influenzas A or B.

When the immune system senses that a cold or flu virus has entered the body, it goes to war. This includes using every weapon at its disposal to attack and destroy the intruders. Unfortunately, this causes the physical symptoms that make having a cold or the flu so miserable. These include sore throat, runny nose, chest congestion, coughing, sneezing, fever, headache, body aches and fatigue. Some people may also experience diarrhea or vomiting.

The symptoms of a cold and the flu are often similar, but the potential outcomes are different. A cold is a milder illness that rarely leads to serious health problems. The flu, by contrast, is more severe than a cold. It can also lead to serious complications, some of them life-threatening. These include viral or bacterial pneumonia, inflammation of the heart or the brain, and sepsis, a response to infection that is so extreme, it can lead to death. The flu can also worsen chronic medical conditions, such as asthma, diabetes and heart disease.

The only reliable way to differentiate between a cold and the flu is with a special test performed on cells and fluids swiped from the inside of the nose or the back of the throat. Two quick tests can be performed in the doctor’s office. These are the rapid influenza diagnostic test, or RIDT, which detects proteins associated with the influenza virus, and the rapid molecular assay, which identifies viral genetic material. Each test takes about 15 minutes, but neither is infallible. More accurate tests, which can return results in several hours, must be performed in specialized labs.

There is no cure for either the cold or the flu at this time. Antibiotics don’t work against them because they kill bacteria, and as we discussed, both the flu and a cold are caused by viruses. Your doctor may offer to treat you with a class of drugs known as antivirals, including Tamiflu, Relenza, Flumadine and Xofluza, a newer drug approved by the Food and Drug Administration in 2018. Antivirals won’t cure you, but when taken soon enough after infection -- about two days -- they may lessen the severity of symptoms and shorten the duration of illness by a few days.

As always, we recommend getting the flu vaccine every year. It’s not too late!

(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.)