Dear Doctor: I recently read that blocking follicle-stimulating hormone can combat post-menopausal bone loss and weight gain in women. Please tell me how to go about blocking that hormone!

Dear Reader: Talk to women who have hit the age of 45 and beyond, and they pretty much agree that maintaining their weight, let alone losing weight, seems much harder than when they were younger. Now a series of studies have put follicle-stimulating hormone, or FSH, into the spotlight.

Produced by the pituitary gland, FSH plays a role in the release of eggs in women and the production of sperm in men. When a woman approaches menopause, the time at which her ovaries cease functioning, her blood levels of estrogen drop and FSH spikes. At this same stage of life, women begin to experience bone loss.

A professor at a medical school in New York City was intrigued by the fact that, even when estrogen levels held steady, bone loss continued to occur. As a result, he began to wonder whether FSH levels might play a role in the effects of menopause. Although he was studying the role of FSH in bone loss, he was startled when fat levels and weight gain were affected as well.

In a series of experiments using mice whose ovaries had been removed, researchers administered an antibody to block FSH. Without ovaries to produce estrogen, which prevents bone loss, the mice should have experienced a drop in bone mass. Researchers were surprised to find that not only did the bone mass of the mice hold steady, they also began to lose fat.

A colleague at another medical center was persuaded to try the same experiment and got the same results. They also advanced their understanding of how and why the mice, despite being forced into menopause, experienced weight loss.

To get into the details, we first need to talk about two types of adipose tissue -- white and brown fat. Unlike white fat, whose job is to store energy for future use, brown fat is loaded with mitochondria, tiny structures within our cells that burn energy and give off heat.

As babies and children, we have plenty of brown fat. By the time we hit adulthood, only small amounts of brown fat remain. In the case of the FSH-deprived mice, their levels of brown fat rose. This caused their metabolism to rev up, burn calories and lose weight.

Considering that women typically gain anywhere from 5 to 15 pounds or more as a result of menopause, with much of it around the abdomen, it's easy to see why these results have sparked widespread interest. But as the researchers themselves point out, it can be a long leap to translate results from mice to human beings. Only time and further studies will tell.

(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: Are some people just not meant to fly? I get severe ear pain when my plane is descending. I've tried chewing gum and repeated swallowing, and I never fly with a sinus condition. Unfortunately, I have clogged-up ears for several weeks afterward. Any suggestions?

Dear Reader: First, let's look at the cause of ear pain when we fly. Initially, we experience a decrease in outside pressure as we ascend into the sky. This decrease causes less external pressure upon the eardrums. Thus, the air behind the eardrums (in the middle ear) pushes them outward.

Airplane cabins are pressurized to minimize this decrease in pressure, and the body does its part as well. For starters, the middle ear equilibrates some of the pressure difference within it by removing the air through the Eustachian tubes, where it is released into the back of the nose and expelled into the environment. Part of that excess air in the middle ear is absorbed by its mucous membranes.

But, as we descend, the external pressure on our ears begins to increase again to that of the landing altitude. This pressure pushes the eardrums inward. Again, the Eustachian tubes are important because they allow the external air to enter through the back of the nose and balance the pressure between both sides of the eardrums.

If a person has significant nasal congestion, the Eustachian tubes can be blocked, meaning the middle ear can't equilibrate on descent. Thus, the outside pressure pushes in on the eardrums, stretching them inward. As you know, this causes significant pain and, in some people, a swelling of the middle ear and a rupture of the eardrum. Infants and toddlers, whose Eustachian tubes are more susceptible to closure, will let you know how these changes in pressure affect them.

Chewing gum and swallowing can help some people by opening up the Eustachian tubes; so too can closing off the nose with the fingers and exhaling forcefully to help bring air into the middle ear. You can even purchase devices that help place air into the nose while swallowing, so as to open the Eustachian tubes.

This advice doesn't pertain to you, of course. It's possible you have chronic nasal congestion caused by allergies or environmental irritants. If that's the case, you have several straightforward options.

Nasal steroids, for starters, can decrease the nasal swelling and increase the ability of the Eustachian tubes to stay open. Because it may take five to six days before you notice an improvement in swelling, I would recommend that you take one of these drugs for three weeks prior to flying. The allergy and asthma drug Montelukast -- taken for a week before flying -- also may help reduce nasal congestion from allergies, benefitting the Eustachian tubes. Then there are over-the-counter nasal decongestants like Afrin, which also can be used to decrease nasal swelling and keep the Eustachian tubes open. There are no good studies on their use for this purpose, but I often recommend using them two hours prior to landing. You can also try -- and this is my recommendation -- a combination of all three.

Before you do, however, my suggestion is for you to ask your doctor why your Eustachian tubes become blocked with air travel. He or she can best guide your next steps. It's unlikely that you simply "weren't meant to fly."

(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 Reader: In our last column, we explored some of the links between sleep deficit and Alzheimer's disease. This was in response to a question from a reader who was worried that his poor sleep patterns, which are becoming more pronounced with age, might put him at risk.

As we said, poor sleep doesn't portend an Alzheimer's diagnosis. But it does have health effects that can range from serious to grave. In the short term, lack of sleep affects learning, mood, memory and coordination. In the long term, chronic sleep deprivation is implicated in diseases like diabetes, obesity, cancer and heart disease.

Experts in the field agree that a healthful night's sleep lasts about eight hours. It is made up of the dream state of REM (rapid eye movement) sleep and several levels of a deeper state known as non-REM sleep. Not only do we need all these phases of sleep for optimal mental and physical health, but we also need them in adequate quantities. There are no shortcuts. And due to the nature of sleep and its effect on the brain and body, it's not actually possible to make up for missed sleep.

The good news is you can take steps to ensure a better night's sleep, but the challenge is following the rules consistently. As we have seen in our own practice, where some sleep-challenged patients can't find the time or impetus to follow through, this can be easier said than done.

Watch the caffeine. From the moment you open your eyes in the morning, a chemical called adenosine is prepping your body for its next sleep cycle. It builds up throughout the day and attaches to receptors in the brain, which then send signals that eventually cause you to feel drowsy. Caffeine blocks those adenosine receptors, so a crucial part of the sleep cycle gets blocked.

While a morning cup of coffee probably won't throw things too far out of whack, caffeine in the afternoon or into the evening can be detrimental to sleep. Alcohol also disrupts sleep. If you're serious about sleeping better, switch to non-caffeinated beverages after breakfast, and skip the nightcap.

Make your life sleep-friendly. Start by putting the screens away at least an hour (some experts say three hours) before bed. Phones, tablets, computers and video games emit so-called "blue" light that disrupts sleep. To our brain and eyes, this light says it's morning. We need the natural light of evening, dusk and then night to signal our internal clocks that it's time to shut down.

Keep your bedroom dark and quiet. Blackout curtains, a sleep mask and earplugs can help overcome disturbances from outside or inside the house. Also, research shows we sleep best in a cool room, from 60 to 68 degrees Fahrenheit.

Set a sleep schedule. Go to bed at the same time each night and get up at the same time each morning. Keep the momentum going on weekends as well.

We know that enacting these changes can be challenging, but keep in mind that good-quality sleep is vital to our physical and emotional well-being. It's worth the effort and the follow-through.