Dear Doctor: Many doctors in my area recommend CoQ10 in conjunction with statin drugs to reduce or eliminate muscle pain. It has worked for my wife, and we have heard lots of anecdotal evidence from friends who use it. What's the evidence behind the use of CoQ10 with statins?

Dear Reader: First, let's take a look at statins. These drugs have been repeatedly shown to lower cholesterol levels -- leading to decreased rates of atherosclerosis, heart attacks and strokes -- but they can have side effects. The most common side effect I've seen among my patients is muscle pain, which is the reason that most people stop these very beneficial drugs.

Now let's look at CoQ10. This coenzyme is needed for energy production within muscle cells. Some studies have shown that statins decrease the concentration of CoQ10 in both muscle tissue and in the bloodstream. The hypothesis is that, if you decrease the CoQ10 levels, you reduce the production of energy in muscle cells and they won't function as well, leading to muscle aches, weakness or inflammation.

In extremely severe cases -- I've seen this in very few of my patients -- statins can lead to the death of muscle cells, and a decrease in muscular CoQ10 may be one of the reasons. Massive cell death can also lead to acute kidney failure, but fortunately, in most cases, after stopping the statin and getting intravenous fluids, the patient's symptoms will quickly improve.

As for whether taking CoQ10 can prevent the side effects of statins, the studies of CoQ10 supplementation with statins are small and not conclusive. A 2007 study in the American Journal of Cardiology showed a 40 percent decrease in pain among statin users who took 100 milligrams of CoQ10 daily versus those who took 400 international units (IU) of vitamin E daily. However, there were only 18 people in the group that took CoQ10, so it's difficult to make an overarching conclusion about CoQ10's benefits. Other small studies have not shown any benefit from supplementation.

A combined analysis of six studies published in 2015 in Mayo Clinical Proceedings found a slight decrease in pain among statin users who took CoQ10, but the decrease was not clinically significant. The authors concluded that a larger study was needed.

Based on these studies, and the lack of a large study to evaluate CoQ10, it would be difficult to recommend CoQ10 to prevent muscle pain. However, judging by some of my patients' experiences and by your wife, some statin users have found significant pain relief with CoQ10.

My general thought on the matter is, if you have muscle symptoms with a statin, you should probably change the type of statin you're getting. Some types, such as rosuvastatin and pravastatin, don't concentrate in the muscles as much as others, causing fewer muscle problems. Switching to them may have benefit. Taking 100 milligrams of CoQ10 may also have benefit, but again, a large trial will be necessary to further evaluate this.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: I'm just about to turn 60, which -- from what I've read -- is when balance begins to become an issue. What can I do to stay steady on my feet?

Dear Reader: Although good balance is important to all of us who face the world on two legs, it's particularly vital to our well-being as we age. Unlike a child, who's likely to bounce right back up and laugh, or an adult, who comes away with a bump or a bruise, a fall for a senior citizen is a serious health risk.

According to the Centers for Disease Control and Prevention, one-fourth of people over 65 have a fall each year. In 20 percent of those falls, the outcome is a serious injury, including head trauma. At least 2 million elderly people per year visit the emergency room due to injuries from a fall. Close to 300,000 of them wind up in the hospital with a hip fracture.

At its most basic, balance is the ability to evenly distribute your weight and remain in control. We use our ability to balance when we stand, sit, walk, run and perform an infinite range of physical tasks. To achieve and maintain balance, our bodies use a complex set of systems that include muscle strength, sensory input like sight and touch, and a cluster of mechanisms in the inner ear that help with motion, equilibrium and spatial orientation.

To prevent a fall, start by reducing your risk. If you wear glasses, make sure your prescription is up-to-date. If you're on any medication, talk to your doctor about possible side effects that could affect balance.

At home, eliminate tripping hazards like uneven floors, loose rugs, stray power cords and clutter on floors. Be sure your home, both inside and out, is well lit. Install grab bars and non-skid mats in the bathroom. Keep a flashlight by your bed for nighttime emergencies.

Staying fit and flexible makes a big difference. When you get out of a chair, try rising without using your hands. Practice standing on one foot -- balance begets balance. Walking backward, which can be a surprising challenge, can help you become more spatially aware.

Yoga and tai chi have both been shown to help with balance. Slow and graceful, these exercises not only help to maintain balance, they can improve it. Weight-bearing exercises to strengthen the arms, back and legs are effective as well.

Many community centers offer a wide range of exercise classes specifically tailored to people who are older. It's a great way to get fit and meet people with whom you can exercise in the future.

And in case you have any doubt that now is a great time to start working on balance, an intriguing new study backs you up. When researchers analyzed 775 participants between the ages of 30 and 90 over the course of several years, they discovered that the decline in balance actually begins during your 50s.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)

Dear Doctor: Because I had an ulcer, three years ago a doctor wrote me a prescription for Prilosec and told me I had to take it for the rest of my life. But lately, articles in the newspaper have seemed to contradict his thinking, suggesting that Prilosec and similar medicines can cause heart problems. What's your opinion?

Dear Reader: Prilosec is one of many proton pump inhibitors (PPIs) that include Prevacid, Aciphex, Protonix, Nexium and Dexilant. These drugs work by blocking the formation of hydrogen chloride in the stomach. This very strong acid is necessary to break down proteins so that they can be absorbed by the small intestine.

I don't know the specifics about the causes of your stomach ulcer -- the size, the depth, whether it was a bleeding ulcer or caused by aspirin or other anti-inflammatory medications -- but I do agree with your doctor that a proton pump inhibitor would be necessary for the healing of the ulcer. These drugs decrease the acidity of your upper gastrointestinal tract, allowing for an ulcer to heal. The normal duration for treatment is from two to 12 weeks.

In some circumstances, a PPI needs to be continued indefinitely, such as when an ulcer doesn't heal, when an older patient has an ulcer that's larger than 2 centimeters, or when a patient has three or more ulcers per year. People with recurrent acid reflux also need to be on prolonged courses of proton pump inhibitors.

While there are benefits to these medications, there also are downsides. Any drug that changes the normal physiological process of the body can have unintended consequences, and PPIs are no exception. With prolonged use, the decreased formation of hydrogen chloride in the stomach can decrease calcium absorption and bone strengthening, increasing the risk of osteoporosis. Prolonged use can also reduce the absorption of magnesium and B12, and increase the risk of intestinal infections, such as those caused by Clostridium difficile, leading to severe diarrhea.

As for your specific question about proton pump inhibitors and heart disease, a 2014 study published in the International Journal of Cardiology compared more than 126,000 people who took PPIs with an equal number who didn't. After 120 days, researchers found a 58 percent increase in the risk of heart attacks among those who took them. The biggest problem with this study is that the authors couldn't assess whether those in the study smoked cigarettes, were obese or had a family history of heart disease.

A 2015 study published in the journal PLOS One analyzed large amounts of data both from people who used PPIs for gastroesophageal reflux and those who didn't. In this study, researchers found a 16 percent increase in the rate of heart attacks among those who took PPIs. The authors didn't find this risk in those taking acid-reducing histamine-2 blockers, such as Zantac, Pepcid or Tagamet. The authors, however, did note that people who take proton pump inhibitors may be sicker patients to begin with and thus may have an increased risk of having a heart attack.

Then there was a 2016 study in The American Journal of Medicine that focused on people taking Prilosec with two blood thinners after having either angina or a heart attack. After 110 days, researchers found no increase in the risk of heart attacks.

Finally, an analysis of 11 studies -- with a total of more than 84,000 patients -- looked at use of proton pump inhibitors in people taking the blood thinner Plavix after having an angioplasty. The authors found a 37 percent increase in the rate of heart events among those taking the proton pump inhibitor Clopidogrel with Plavix and those taking just Plavix, but they found no difference in death rates. The findings suggest that PPIs decrease the ability of a blood thinner, like Plavix, to work.

Overall, it's clear we need better studies of the potential link between proton pump inhibitors and heart disease.

Your worry about taking Prilosec for the rest of your life is understandable, but you're probably on the drug for a good reason. Just know that there can be long-term side effects, and be aware of them. You can also ask your doctor to keep you apprised of any new research on long-term use of PPIs.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095.)