Dear Doctor: Can asthma medications really reduce the risk of Parkinson’s disease? It runs in my family, so should I start taking the medications as a preventive?

Dear Reader: A few years ago, research published in the journal Science revealed a surprising property of several drugs, including those that contain compounds known as beta-2 adrenergic agonists. These are found in drugs like salbutamol, also known as albuterol, a bronchodilator used to help open the airways of people with asthma and other respiratory diseases.

The stated goal of the research was to identify any existing drugs or compounds that could diminish or eliminate the presence of alpha-synuclein, a protein that accumulates in the brains of people with Parkinson’s disease. To that end, the team of researchers cultured human nerve cells in the lab and exposed them to more than 1,100 different medications, dietary supplements and vitamins. In the course of their testing, they identified several compounds that interfered with the production of that protein. These included asthma medications that contain beta-2 adrenergic agonists. This suggested that certain asthma meds may have potential in the management of Parkinson’s disease.

Parkinson’s disease is a progressive neurological disorder that affects the areas of the brain that control movement and balance. An estimated 1 million Americans are currently living with the disease. The disease develops gradually and is most often diagnosed in later years, at around age 60 or older. Symptoms can include tremors, slowed movement, muscle stiffness or rigidity, difficulty standing, poor balance, difficulty walking, changes to speech and vocal expression, changes to handwriting and in some cases, loss of cognitive function.

Although it is known that the symptoms of Parkinson’s are linked to changes in the brain that cause certain cells and tissues to malfunction and die, the reason this happens is not yet known. However, scientists have observed a buildup of protein clumps, known as Lewy bodies, in the brains of Parkinson’s patients. It’s because Lewy bodies consist mainly of alpha-synuclein that the researchers we’re discussing began their search for compounds to interfere with that specific protein.

Once the researchers isolated the drugs that interfere with alpha-synuclein, they needed a way to identify asthma patients and their health outcomes. They found what they needed in a database in Norway, which tracks all prescription medications. The researchers selected a group of 600,000 individuals who had used the asthma drug that we in the United States know as albuterol. When they looked at the incidence of Parkinson’s disease among all individuals in the drug database over the course of an 11-year period, it turned out that people who had used albuterol were 30 percent less likely to develop Parkinson’s than those who had never used the asthma medication. Those who used the highest doses of albuterol had half the incidence of Parkinson’s disease, according to the study.

As to your question about using asthma meds as a preventive, the researchers say -- and we wholeheartedly agree -- the answer is no. The origins of Parkinson’s disease are unclear, and the findings from the study are not fully understood. However, this new research is promising and is likely headed to clinical trials. We haven’t heard the last of it.

(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: I read about a study that said smelling junk food you want to quit eating -- hello, pizza and donuts! -- will stop your craving. Is that really true? I want to eat healthier, but some foods are so hard to resist.

Dear Reader: This particular theory hadn’t crossed our radar until we read your letter, but we did a bit of digging and found the study you’re referring to. It was conducted by researchers at the University of South Florida and published at the start of the year in the Journal of Marketing Research.

The study's findings were as you say -- the sustained scent of a tempting snack food had the effect of easing the craving for that snack. That’s somewhat ironic, considering the point of the study was to examine more closely the practice of using ambient scent in public settings as a marketing ploy.

These ambient scents are part of an increasingly common practice in which retailers infuse areas with seductive smells to act as "aroma billboards," as one advertising company put it, to drive food sales. Anyone within sniffing distance of a Cinnabon stand in a mall has directly experienced this technique. Stories about the practice mention chocolate-scented strips placed on vending machines in California that caused the sales of Hershey bars to triple, a grocery store in New York whose bakery sales spiked whenever the scent of fresh-baked bread was pumped through the aisles, and the use of a variety of hidden scent machines throughout Disney properties to encourage spending. The practice is used in nonfood-related marketing, too, with a variety of pleasant scents used to make shoppers subliminally happy in order to loosen their purse strings.

According to the study you asked about, it turns out there’s an important catch when it comes to the scent-driven marketing of food: The researchers found that whether or not a scent triggered a craving was directly related to the amount of time someone spent smelling it. The tests were conducted in several sites, including a grocery store and a middle school cafeteria.

Researchers used a hidden nebulizer, which is a device that broadcasts scent. Individuals were exposed to alternating pairs of scents, one of a healthful food, and one of a junk food item. The scent of strawberries was paired with the aroma of chocolate chip cookies, and the scent of apples was paired with that of pizza. A quick whiff of a cookie -- 30 seconds or less -- often led to the cookie being selected rather than the strawberry. But when the cookie scent lingered for 2 minutes or more, the cookie lost its allure, and participants chose to eat the strawberry instead. The apple-pizza combo had the same time-dependent results. The takeaway is that by inhaling the scent of a tempting food long enough, you’ll move past craving it and arrive at the point where the scent itself has satisfied the craving.

A final word -- this was a single experiment on a complex subject, and scientists, including the researchers, agree further study is needed to fully understand the results.

(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: I read that a girl went blind in one eye after playing video games on her phone for an entire day. Is this even possible? Should I be worried about my kids, who are video game addicts?

Dear Reader: You’re referring to a news story from China that made headlines a few years ago. The woman in question, who was 21 at the time, reportedly spent an entire day playing an online video game and suddenly lost the vision in her right eye.

Doctors diagnosed her with retinal artery occlusion, a blockage in the main vessel that supplies blood to the retina. The retina is the layer of light-sensitive tissues at the back of the eye that translate the energy from incoming light into impulses. These impulses then travel via the optic nerve to the brain, where they are interpreted as visual images.

When the retinal artery becomes blocked, oxygen-rich blood can’t reach the retina. This can result in cell death and vision loss. The speed at which the cells of the retina die and the extent of the damage depends on the degree of arterial blockage and how long it lasts.

Retinal artery occlusion usually occurs in people 60 and older, and it is slightly more common in men. The cause of the blockage is usually a blood clot or an embolus, which is a bit of foreign matter in the bloodstream, such as an air bubble or a bit of fatty deposit. Risk factors for the condition include high blood pressure, diabetes, heart arrhythmias, carotid artery disease, the use of oral contraceptives, faulty heart valves and blood platelet abnormalities, to name just a few. It is not known which specific risk factors applied to the woman in the story.

At this time, there are no reliable treatments for retinal artery occlusion. Most involve procedures to somehow dilate the affected artery, dislodge the blockage and restore normal blood flow.

Regarding the claim that the young woman’s marathon gaming session caused the arterial blockage, there turns out to be a bit more to the story. With an estimated 2.3 billion-with-a-B people worldwide regularly playing online games, addiction has become a serious concern. In China, authorities have identified online gaming addiction as a public health crisis. Stories of gamers forgetting to eat, skipping school, getting fired from work and even wearing disposable diapers in the pursuit of their online gaming passions abound.

The patient in the news story had been playing a hugely popular game known as Honor of Kings. The parent company claims to have more than 80 million daily active users, and 200 million players per month. Some observers believe that, despite the lack of an established medical connection between extreme eye strain and retinal artery occlusion, authorities have used the patient’s medical emergency as a vivid cautionary tale to fellow gamers.

When it comes to your own kids, it’s highly unlikely that their gaming habits will physically blind them. However, any time a single activity takes precedence over daily activities and other life interests, we believe there is cause for concern.

(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.)