Dear Doctor: A relative of mine was recently diagnosed with Parkinson’s disease. I read recently that exercise can help slow the progression, so I want to suggest it to him, but I don’t know if it’s actually true.

Dear Reader: Although Parkinson’s disease is a progressive neurologic disorder that increasingly limits a person’s ability to move, a robust body of research points to the benefits of exercise for people with the condition. Symptoms of Parkinson’s, which typically appear gradually, can include tremors, poor balance, slowed body movement and stiffness. Most cases are diagnosed in people 60 and over. At this time, an estimated 1 million Americans have been diagnosed with Parkinson’s. With thousands of baby boomers turning 65 each day, the number of Parkinson’s diagnoses is expected to spike.

Older studies have shown that a variety of exercises help with a range of issues common to Parkinson’s, including balance, flexibility, strength and motor coordination. For example, the slow, sustained movements of tai chi and yoga help improve gait and balance, while aerobic exercise enhances endurance, agility and coordination. But when it comes to actually slowing the progress of the disease, we think you’re referring to a study conducted by researchers at Northwestern University’s Feinberg School of Medicine. The results were published in JAMA Neurology in December 2017.

This study, which researchers say is the first of its kind, explored the potential benefit of high-intensity exercise for patients with early-stage Parkinson’s disease. Previously, high-intensity exercise was not considered appropriate for Parkinson’s patients. Each of the 128 patients enrolled in the study had early-stage disease and had not yet begun taking any medications. This was done to eliminate response to medication as a variable in the study.

The participants were divided into three groups and had their baseline physical condition evaluated according to a Parkinson’s disease scale. During the six-month study, one group of patients exercised three times per week at high intensity, which was defined as 80% to 85% of maximum heart rate. A second group exercised three times per week at medium intensity, or 60% to 65% of maximum heart rate. The third group, which served as the control, did not exercise.

After six months, participants were re-evaluated on the Parkinson's disease scale, which ranges from 0 to 108. The lower the number, the less severe the symptoms. For those who did high-intensity exercise, the group’s baseline reading of 20 remained unchanged. For the patients who exercised at moderate intensity, their baseline reading of 20 increased by 1.5 points. For the control group, which did no exercise, their baseline reading of 20 increased to 23. As the researchers point out, that 3-point increase translates to a 15% increase in primary signs of the disease. Not only is this statistically significant, it results in a lower quality of life for patients.

If you share this study with your relative, please urge them to check with their doctor before starting any kind of exercise program. Decisions best made with a physician’s help include which specific exercises to take part in, which to avoid, and intensity and duration.

(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: A good friend of mine is into this new thing called resistive breath training. She says it helps runners build endurance, and she even bought a breathing gadget to practice it. Does it really help?

Dear Reader: Resistive breath training, also known as inspiratory muscle strength training (IMST), is a type of resistance training for the muscles we use to breathe. It can be accomplished through a series of controlled breathing exercises or, as your friend is planning, with a hand-held device. Known as an inspiratory muscle trainer, this type of device typically consists of a mouthpiece through which the person breathes and some sort of adjustable valve that creates varying degrees of resistance for the exerciser to work against.

While IMST may not be familiar to you and your friend, it’s not actually a new technique. Resistive breath training was developed many decades ago to help people with various breathing problems, including COPD, asthma and the after-effects of bronchitis. It is also used to help people to successfully withdraw from mechanically assisted breathing.

In a study dating back to 1979, researchers found that IMST helped patients living with severe COPD to achieve improved breath control, as well as improved expectoration, the ejection of phlegm and mucus from throats and lungs. Subsequent studies continued to find benefits in the practice.

It’s possible that your friend’s interest in IMST arises from a spate of news reports about preliminary findings by researchers from the University of Colorado, which were presented last month at the annual Experimental Biology conference.

The seed for the experiments was planted several years ago, when researchers from the University of Arizona looked into IMST as a way to help individuals living with obstructive sleep apnea. This is a potentially serious disorder in which muscles in the throat relax enough during sleep to completely block airways. In addition to confirming that by increasing resistance, the length of each IMST session could be shortened, the Arizona researchers saw a surprising side effect. After six weeks of therapy, systolic blood pressure in the study participants dropped significantly. Systolic blood pressure -- that’s the top number in a blood pressure reading -- is the pressure in the blood vessels during a heartbeat. (The bottom number is the pressure in the blood vessels between heartbeats.) High blood pressure is one of the major risk factors for cardiovascular disease, which is the leading cause of death in the United States.

The results of the Arizona research spurred scientists at the University of Colorado to build upon the findings. In their own series of experiments, which are ongoing, the Colorado researchers saw the same significant drop in blood pressure in participants who performed IMST. They also recorded improvements to large-artery function. The IMST group also saw improvement in cognitive function and in endurance and heart-lung efficiency while exercising on a treadmill. Neither of those changes were seen in a control group, which used a breathing device that delivered only low resistance.

These results are impressive, but, as the researchers themselves point out, they are preliminary. The researchers stress, and we agree, that anyone considering IMST should first check with their doctor.

(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 back to our monthly letters column. Let’s dive in!

-- We had several questions regarding how E. coli is finding its way into romaine lettuce, and whether thorough washing can render suspect batches of leafy greens safe again.

To the first question, the answer is that there are numerous potential entry points in the food chain between farm and table. Contamination of E. coli can come from wild birds or animals, fertilizer, irrigation water and the many humans who handle our food as it moves through the stages of production. Each situation in each new outbreak is unique.

As to whether you can successfully wash E. coli out of your lettuce, the answer is no. Even after a sustained and powerful washing, enough of the microscopic toxins will remain in the countless nooks, crannies and crevices of the lettuce -- or other vegetables -- to get someone sick. The advice is to not only throw all suspect produce away, but to use bleach to clean the shelf or drawer it sat in.

-- After a column about the spike in STDs in young people, we heard from a reader regarding the HPV vaccine for older adults. Human papillomavirus, one of the most common sexually transmitted infections, can lead to cancer or genital warts. “News reports keep saying that teenagers should get the HPV vaccine,” the reader wrote. “But what about those of us over 30? Heck, I’m over 60 -- and I worry. Back in the day, we didn’t know about the risks of oral sex. We thought it was safe. Could you explain the risks -- and what we should do now?”

Gardasil, the HPV vaccine, was originally recommended for young people between ages 9 and 26 years. The rationale was that the optimal time for HPV immunization is prior to an individual’s first sexual contact. After age 26, there is an increased likelihood of prior exposure to HPV, which reduces the potential benefit of the vaccine. However, for anyone with no prior sexual exposure, or with a single sexually monogamous relationship, the risk of prior HPV exposure may be low enough to recommend the vaccine. The good news is that in October 2018, the FDA approved Gardasil for people aged 27 to 45. We hope that insurance coverage will soon follow.

-- After a column about an extreme reaction to a food allergen, a registered nurse from Wisconsin asked us to remind everyone of the lifesaving potential of the EpiPen. “I am an allergy nurse and feel there were missed opportunities to educate the public,” she wrote. “People with food allergies should avoid those allergens AND be prepared to promptly treat, if necessary, with injectable epinephrine.”

We’ve said it before and we’ll happily say it again -- if you have a food allergy, please always carry an EpiPen or other form of injectable epinephrine. It can save your life.

Thank you, as always, for your thoughts, comments and -- we’re always so touched -- kind words. We’ve had a lot of clinical questions lately, so just a reminder that unfortunately we can’t offer diagnoses or give second opinions. See you with more letters 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.)