Dear Doctor: I've had back pain since my 20s and have gotten to the point where I can't use aspirin or other pain relievers because they tear up my stomach. My sister-in-law wants me to try meditation, which sounds a little nutty. Do you think it can help?

Dear Reader: The power of the mind over the body is a concept that has been explored, questioned, promoted and ridiculed for centuries, if not millennia. However, the latest studies on the subject offer intriguing insights. Researchers are uncovering evidence that techniques such as meditation and mindfulness can be an effective means of dealing with pain. This is good news for the estimated 11 percent of Americans who live with chronic pain.

Several recent studies have focused on meditation and mindfulness techniques to alleviate lower back pain, with some surprising results. Not only did researchers add to the growing body of evidence that mind-based techniques can be effective, but they also discovered that the relief from pain comes via unexpected pathways.

One study involved 342 adults between the ages of 20 and 70 who had lower back pain for three or more months, a length of time for it to be considered chronic. None of the individuals could attribute the onset of their pain to a particular cause, such as injury, overuse or disease.

The participants were divided into three treatment groups -- one that followed the traditional medical approach of rest, activity modification, heat or ice, and over-the-counter pain relievers. A second group learned a technique called cognitive behavioral therapy, or CBT, which addresses thought and behavior. The third group was taught something the researchers called "mindfulness-based stress reduction," which included several types of meditation as well as gentle yoga practice.

Six months later, 61 percent of each mind-based treatment group reported improved physical function. About 45 percent of them said they had less back pain. That was measurably better than the group assigned to traditional medical practices. In that group, 44 percent reported improved function, and 27 percent said they had less pain.

While the results may not be extraordinary, they are significant. And as acceptance of this novel pain relief pathway grows, the hope is that continued research will lead to greater understanding and to new techniques that are even more effective.

Speaking of understanding, the results of a study published in the Journal of Neuroscience last year also offered a few surprises.

When you hurt yourself -- stub your toe or scrape your knee -- your body responds with a flood of natural opioid compounds that make the resulting pain more bearable. But for the participants in this study, researchers blocked that pain relief pathway. Yet patients involved in meditation still reported feeling less pain in response to unpleasant stimuli than those who did not meditate. This led researchers to conclude the pain relief mechanism of meditation occurs independent of the opioid receptors in the brain.

Bottom line: Your sister-in-law has a point regarding meditation. With a bit of research, you can find a class or program in your area. And if you do follow through, please let us know how it goes.

(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. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Ever since the news about lead in the drinking water in Flint, Michigan, I've wondered about the water in my own home. I live in Oklahoma, and our house was built in 1988. Should I be worried?

Dear Reader: You've asked a timely question that, unfortunately, has a complex answer. Let's start with why the presence of lead in our environment -- whether in the water, air or soil, or in the products we use or come into contact with -- is of grave concern.

Lead is a highly toxic metal that has a detrimental effect on virtually every system in the human body. Children, with their developing brains and nervous systems, are particularly vulnerable to the effects of lead. The amount of lead that an adult can tolerate with minimum ill effect can cause significant damage to a child. The challenge is that until it becomes acute, lead poisoning virtually has no symptoms.

Lead causes anemia, hypertension and damages the kidneys and the reproductive system. Even low blood levels of lead affect the development of the brain and nervous system. In children it can result in lower IQ, hearing problems and behavioral changes like reduced attention span. The neurological damage caused by lead is believed to be irreversible.

Exposure to lead is bio-accumulative. That means the lead you ingest stays in the body and, as exposure continues, blood levels increase. And although the health crisis in Flint has put the spotlight on lead in water, the presence of lead-based paint in older homes poses the most common risk. It's a topic we've addressed in a previous column.

As for your situation, there is some good news. In 1986, two years before your home was built, the Safe Drinking Water Act significantly reduced the amount of lead permitted for use in plumbing fixtures, including pipes and solder. However, it wasn't until 2014 that the most stringent regulations regarding the use of lead in water delivery systems went into effect.

You will also want to find out whether your water supplier is in compliance with federal lead contamination regulations. Federal law requires regular testing for contaminants. The results are published in a document called the Consumer Confidence Report. Ask for a copy. Should you wish to test your own water, the Environmental Protection Agency has a list of certified labs on its website. Most home improvement stores also sell water-testing kits.

If you believe your water supply is contaminated with lead, the EPA suggests the following:

-- Flush your pipes for 30 seconds to two minutes before using water for drinking or cooking.

-- Use only cold water for drinking or cooking. Hot water may contain higher levels of lead.

-- According to the EPA, it is safe to bathe or shower in water that contains lead, as it is not absorbed through the skin.

-- Consider installing a water filtration device that is certified to remove lead.

We recommend a visit to www.epa.gov, where you'll find a wealth of information and resources.

(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. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I love swimming and doing water exercises in the pool. The problem is that I tend to get painful cramps in my legs and feet. Is there anything I can do to avoid them? Does my age (I'm 69) have anything to do with this?

Dear Reader: Muscle cramps in the legs -- the calf and thigh, as well as the feet -- are a fact of life for some of us who exercise. And while there are many theories as to why they occur (many of them presented quite forcefully as fact), the truth is, we don't really know the cause. It does appear that cramps, or muscle spasms, can become more common as we age. That's particularly true of leg cramps that occur at night, during sleep. For others, as you have discovered, they can intrude into the activities of daily life.

What's happening is that, due to a nerve malfunction, the muscle fibers suddenly contract and don't release. Unless you've ever lived through a muscle spasm (sometimes it's called a charley horse), you can't understand just how helpless you feel and how painful it is. And while the spasm itself typically ends relatively quickly, that area of the muscle may feel tender for a day or so.

If you decide to check in with your family doctor regarding the onset of these muscle spasms, he or she will most likely begin with a physical examination of the area involved. Your doctor will also collect the information needed to rule out any underlying disease or condition that could be the cause of the spasms. This includes diabetes, kidney disease, heavy drinking or alcoholism, and peripheral artery disease. The latter, which Dr. Ashley covered in a recent column, is a condition in which certain arteries, including those in the legs, become narrow. Pregnant women are also prone to muscle cramps, particularly in the final months before delivery.

Other factors in persistent leg cramps can include a pinched nerve, flat feet, muscle fatigue from overuse and an imbalance of essential minerals such as calcium and magnesium. Muscle cramps can also be a side effect of certain medications, such as diuretics and statins.

We see two potential factors associated with muscle spasms in your situation. One is muscle overuse, and the other is cold temperature. Do the cramps occur in the later stages of your workouts? If so, try taking a break before you reach that danger zone. Hop out of the pool, get something to drink, warm up your legs with a quick walk. Do some stretches and massage the muscles before getting back into the pool.

Another area of agreement around muscle spasms is the importance of potassium, calcium and magnesium in neural health. Dark leafy greens are a good source of magnesium. Potassium-rich foods include sweet potatoes, bananas, broccoli, halibut, cantaloupe and orange juice.

When a cramp does occur, gently massage the affected area and gradually stretch the muscle. It's possible for a cramp to last up to a minute or more, so be patient. And if the cramps are severe enough to interfere with daily life, please do get in touch with your doctor.

(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. Owing to the volume of mail, personal replies cannot be provided.)