Dear Doctor: It seems as though we're hearing more and more about inflammation and how it causes disease. What is inflammation and how does it work? And is it really possible that what you eat makes a difference?

Dear Reader: You've asked some pretty big questions, so we're going to answer them in two parts. In this column, we'll explore inflammation itself. We'll address whether what you eat can have an effect on inflammation (spoiler alert -- yes) in our next column.

First of all, you're correct that there's been an increase in awareness about the concept of inflammation in the last few years. At its most basic, it's the body's localized response to injury or infection. When you catch a cold, scrape your knee or get a sunburn, inflammation is the cause of the swelling, heat, pain and redness that follow. And while it sounds simple, the pathways and mechanisms of inflammation, as well as the many ways it can act upon the body, are really quite complex.

The human body is perpetually on guard for anything that may harm it. This includes physical injury to skin, bone, organs or tissues, or potentially dangerous invaders such as bacteria, viruses, pathogens or other harmful stimuli. When damage is detected, the body's immune system rallies. Many different types of immune cells "wake up" and begin to release a variety of substances, each of which causes a rapid series of protective responses. This is part of a process known as acute inflammation.

Blood vessels expand so they can quickly send additional blood to the injured area. They will also temporarily become more permeable, so as to flood the site of damage with specialized chemicals produced by white bloods cells, which are our first line of defense against infection. These responses are what cause the injured area to turn red, feel hot and become swollen.

Some of the substances released in the immune response will also cause surrounding nerves to send pain signals to the brain. That causes your attention to be drawn to the site of the injury, which you will then shelter from further damage. For example, when you sprain your ankle, the pain and swelling automatically lead you to favor the injured side.

Without the inflammation response, our wounds and injuries would not heal. However, things can go awry. Sometimes the immune system will issue an inflammation response against otherwise innocuous substances, like pollen, certain foods or pet dander. The result is allergies, which can range from annoying to life-threatening.

Even more challenging is chronic inflammation, an immune response that lasts for months or even years. It happens when the body targets its own cells and tissues, which can result in disease. For example, rheumatoid arthritis is caused when joints throughout the body are permanently inflamed. Psoriasis is a chronic skin disease caused by inflammation. Inflammation of the bowel can cause conditions like Crohn's disease, celiac disease and ulcerative colitis. And inflammation plays a role in cardiovascular disease, heart attack and some cancers.

In our next column, we'll dive into the second half of your question -- can food have an effect on inflammation?

(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've suffered joint pain for years. Being prescribed 15 milligrams of meloxicam has been wonderful. What are your thoughts on meloxicam use?

Dear Reader: Meloxicam (Mobic) is a non-steroidal anti-inflammatory drug (NSAID) that, like all such drugs, inhibits the formation of the enzyme cyclooxygenase (COX). This inhibition leads to a decrease in the production of molecules that boost inflammation and help the blood clot.

There are two forms of the COX enzyme, aptly named COX-1 and COX-2. COX-1 is involved in protecting the lining of the stomach, promoting the blood's clotting ability and aiding kidney function. COX-2 is involved in the inflammatory response in the body. Many of the side effects seen with older NSAIDs such as ibuprofen, naproxen and diclofenac are related to the inhibition of COX-1. The side effects include gastritis or gastric ulcers, blood thinning and kidney damage. Inhibiting COX-2 leads to a decrease in inflammation and a decrease in pain.

Meloxicam at low doses (7.5 milligrams) inhibits COX-2 and not COX-1. That means it can reduce pain and inflammation without irritation of the stomach lining or an increased risk of stomach ulcers. Research has found that serious upper gastrointestinal events at the 7.5 mg dose occur in fewer than 1 in 3,000 people. But note that follow-up studies didn't last more than 60 days, so it's unclear if these rates would hold up over the long term.

Further, at low doses, meloxicam may not trigger the kidney problems that other NSAIDs cause. The rates of heart attacks appear comparable to those of other NSAIDs, with a slight increase in risk at all doses.

However, when meloxicam dosage is increased to 15 mg, the medication does inhibit COX-1, leading to a significant increase in the rates of serious upper gastrointestinal events.

One study found that, while the number of events was less than with the NSAID naproxen, the number of events at 15 mg was six times higher than the lower dose of meloxicam (1 in 500 people). Another study showed a greater proportion of people taking 22.5 mg of the drug for 12 weeks had a slight decrease in kidney function. This was not seen at the 15 mg dosage.

Lastly, for people on two types of blood pressure drugs -- ACE-inhibitors and angiotensin receptor blockers -- meloxicam (like other NSAIDs) may make those medications less effective.

In summary, meloxicam works well for pain and swelling. The higher doses do decrease pain more than the 7.5 mg dosage, and the medication is comparable to the NSAID diclofenac for both pain relief and decreasing inflammation. I have frequently recommended the medication for joint inflammation, bone bruises and pain from fractures and tendonitis, and it's worked well for the majority of my patients. For older adults, I lean toward the 7.5 mg dose, but I have recommended 15 mg in more severe cases. Some of the latter group have complained of gastrointestinal discomfort, but this stopped when they discontinued the medication. I rarely give this medication for greater than one month, but have had some patients with severe arthritis who have been on this medication for years.

I don't know how frequently you are using meloxicam, but if you're using it on an as-needed basis, it should be safe. If you're using this medication daily, you should consider its potential for side effects.

(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've been hearing on the news that researchers have discovered that when stress causes a heart attack, it all begins in the brain. How does this work? And is it even possible to control the way our brain responds?

Dear Reader: Before we dive into the details of the intriguing revelations regarding stress and heart health, we'd like to share some soothing news. The same mind-body connection that researchers believe plays a role in heart attack may also offer a measure of protection through techniques like meditation, yoga and mindful relaxation.

Let's start with the known risk factors for cardiovascular disease, which have been front-page news for decades. Obesity, high cholesterol, hypertension, diabetes and smoking -- we doubt any of our readers are surprised by that lineup. And while mental and emotional stress have long been suspected to contribute to heart disease, the exact mechanism has remained a mystery.

Now researchers from Harvard Medical School have identified the part of the brain that plays a significant role in cardiovascular disease. Known as the amygdala, it's a small, almond-shaped area associated with processing emotion. The amygdala receives and interprets input from throughout the brain. When incoming signals point to danger, the amygdala reacts instantly, bypassing conscious choice. It sets the sympathetic nervous system, which regulates the fight-or-flight reflex, into action.

Using imaging techniques to measure brain activity, the researchers could link increased activity in the amygdala to increased production of white blood cells by the bone marrow. This led to inflammation in the arteries, which is a risk factor for heart attack and stroke.

The good news is that by using techniques to reduce the stress response, we not only feel more calm and serene, but the benefits can also extend to cardiovascular health. So be good to your amygdala (and to your heart) and consider some options.

Many workplaces, community centers, university extension programs and senior citizen centers now offer stress-reduction programs. At the very least, they will bring you together with like-minded individuals. Social isolation is associated with increased stress, so simply becoming part of a community with a common goal is a step forward.

Yoga has long been shown to reduce stress and promote physical, emotional and mental well-being. In fact, studies show that individuals who practice yoga regularly have lower levels of certain stress chemicals in their blood than those who don't do yoga. And although many forms of yoga have sprung up over the years -- some of them quite fast-paced and with a mindset that is almost competitive -- we recommend the gentle and measured approach of basic hatha yoga.

Meditation is also quite effective at reducing stress. Again, studies have shown that people who meditate regularly for just as little as 20 minutes per day reduced their blood pressure and reported feeling less stressed than did their non-meditating counterparts.

Tai chi, Pilates and deep breathing are also good for stress reduction. And don't forget the healing power of the natural world. A contemplative walk in the woods or a park will help you leave your worries behind.

(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.)