Dear Doctor: Our dad is 67 years old and just got a diagnosis of mild cognitive impairment. His doctor told us that getting regular exercise can help. I’ve never heard this before. Is there a scientific basis, or is the idea just for dad to stay healthy?

Dear Reader: Mild cognitive impairment, also referred to as MCI, is a worsening of the skills we use to learn, reason and remember. It affects up to one-fifth of adults over the age of 65. Although, as the name of the condition suggests, the changes to cognition are slight, they are, nonetheless, noticeable. People with mild cognitive impairment are also at increased risk of developing various types of dementia, including Alzheimer’s disease.

An area of study that continues to generate great interest is the beneficial effects exercise may have on cognition and dementia. Research that analyzes years of health and behavior data collected from specific groups of people has found that individuals who exercise regularly can measurably reduce their risk of developing dementia when they age. There is also evidence that these protective effects can carry over to people who continue to exercise in their later years.

A new study, published in November in the journal Alzheimer’s Research and Therapy, found people with MCI who did even a modest amount of exercise each day could be helping to delay the onset of more cognitive decline. Researchers examined health data collected from almost 250,000 people over the course of six years. The majority were between the ages of 65 and 70 and had been diagnosed with mild cognitive impairment. The subjects were divided into four groups: those who never exercised, those who had just begun to exercise, those who had recently quit exercising and those who had exercised prior to their diagnosis and continued to exercise regularly. Each of the groups self-reported the data about their physical activity.

Among the findings was that, when compared to the group that never exercised, those who had exercised prior to and after their diagnosis of MCI reduced their risk of progressing into dementia by 18%. For those study subjects who had begun regular exercise after receiving their diagnosis of MCI, the risk of progressing to dementia decreased by 11%.

When it came to defining physical activity, the researchers set the bar pretty low. They classified it as 10 or more minutes of moderate or vigorous exercise done more than one day per week. Not that surprisingly, they also found that exercising longer and more often conferred increased benefits. The scientists surmised exercise may have protective effects because it raises the levels of certain proteins in the brain, which help with neuron development and maintenance. They also suggested a link to the increase of blood flow to the brain during exercise. When physical activity ceased, so did the positive cognitive effects it conferred.

As with all studies with self-reported data, the conclusions rely on the accuracy of the participants’ record-keeping. Still, the physical and mental health benefits of regular exercise are well known. An exercise program tailored to your dad’s health and abilities could be helpful.

(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 again, dear readers, and welcome to the first winter edition of our monthly letters column. To those of you who have been sending us questions via the U.S. mail, we’re happy to report that those letters have finally been retrieved. We’ll begin answering soon. But first, we want to address some of the questions we’re getting regarding the coronavirus vaccine.

-- A licensed registered nurse who is in line to get the vaccine soon had a good question: “Today is the first day of the COVID-19 vaccine being administered,” she wrote. “I am scheduled for my second SHINGRIX (against shingles) shot this coming Friday. Should there be a lapse between the two vaccines, or does anybody know?”

The answer to your question isn’t yet clear. But let’s take a look at the common side effects of the coronavirus vaccine, which are pain at the injection site, fatigue, headache, muscle pain, chills, joint pain and mild fever. Some of these overlap with side effects of the SHINGRIX vaccine. In order to differentiate between the two vaccines, and to understand which is the one causing any side effects that you may experience, our recommendation is to separate the two injections by at least a few days.

-- Several of you have written with questions about getting vaccinated when there are existing allergies. “Can a person who is allergic to penicillin and aspirin take the vaccine safely?” a reader asked. When it comes to an allergy to penicillin, or to aspirin or other non-steroidal anti-inflammatories (NSAIDs), the data collected during the clinical trials for the vaccines doesn’t report either as a reason to avoid the vaccine. However, The Centers for Disease Control and Prevention recommends that anyone who is allergic or hypersensitive to any of the components of the vaccine should not receive it. Your doctor, or the vaccine provider, can help you with that information.

Everyone who gets the vaccine should be monitored on-site for at least 15 minutes post-injection. Individuals with a history of severe allergic reactions to any other vaccines, or to other injectable therapies, should consult with their doctors before getting the vaccine. CDC guidelines state that people with a history of severe allergic reactions that are not related to vaccines or injectable medications, such as to foods, pets, venom, or environmental or latex allergies, may still get vaccinated.

When getting the coronavirus vaccine, be sure to disclose any existing allergies; whether you have a fever, are immunocompromised or are on a medicine that affects your immune system; are pregnant, planning to become pregnant or are breastfeeding; and whether you are on a blood thinner or have a bleeding disorder. And if you have already received another COVID-19 vaccine, it’s important to disclose that as well.

-- A reader who is worried about a possible adverse reaction to the vaccine wonders how she will be safe while getting her shot. The answer is that the CDC has asked all vaccination providers to have on hand the appropriate medications and equipment to deal with a possible allergic reaction. This includes epinephrine, antihistamines, stethoscopes, blood pressure cuffs and timing devices to check your pulse.

(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: It seems like a coronavirus test you can do at home would be really helpful. Then people who don’t have symptoms could know that they should quarantine, and maybe that would help stop the spread. Is there anything like that on the horizon?

Dear Reader: Not only are home coronavirus tests already a reality, the U.S. Food and Drug Administration has just issued an emergency use authorization for the first rapid coronavirus self-test that will be available without a prescription. This test, called the Ellume COVID-19 Home Test, got the nod from the FDA on Dec. 15, 2020. It joins the Lucira COVID-19 All-In-One Test Kit, a prescription-only home test, which the FDA approved last November. It is expected to become available in 2021, and will reportedly sell for about $30. Both tests utilize a nasal swab.

The over-the-counter home test has been authorized for self-use by people who are 16 years and older. Those individuals may then administer the test to people under the age of 16, including to children as young as 2 years old. The reason for the age limitations is to assure that the person is able to accurately perform the multiple steps needed to complete the test.

Although not as accurate as lab-based tests, Ellume’s test still got high marks. In a clinical study of almost 200 people, the test detected 95% of the infections found by the lab-based test. Another advantage of the new test, in addition to not requiring a prescription, is that it can be used by people who do not have symptoms of COVID-19. However, in asymptomatic cases, studies showed that the rate of accuracy dropped to 91%.

If you do take a home test and get a positive result, it’s time to self-quarantine. Mild-to-moderate symptoms of COVID-19 can be managed at home. However, if breathing becomes compromised, it’s important to seek immediate medical care.

While the increasing availability of home coronavirus tests is a big step forward in controlling the spread of the virus, it’s important to note that they are just one part of a multi-prong approach. It’s still important to wear a good mask whenever you’re outside of the home, particularly when you’re indoors. Remember that your mask not only protects others from your exhaled breath, but it also offers a degree of protection to you as well. Continue to avoid gatherings of people outside of your core group, maintain social distancing when in public, and remain vigilant about hand-washing and keeping high-touch surfaces clean.

It’s only when taken together that these precautions offer the best protection. A great metaphor that we heard recently is to think of each precaution as a slice of Swiss cheese. When you look at them one at a time, the slices of cheese have holes. But when you pile the slices up on top of each other, they act together to form a barrier. Each coronavirus precaution has its weakness, but they don’t all have the same weakness. So, by adhering to all of the precautions, you’re compensating for the various shortcomings and giving yourself the best chance at avoiding infection.

(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.)