In response, we send out troops in the form of antibodies (including a regiment actually called "natural killer cells") to defend our native territory.
If the good guys win, our health prevails. If the bad guys win, we're sick.
But the newest way to think about healing (which also, coincidentally, is the oldest way) is how to nurture what's good rather than destroying what's bad -- a matter of plowshares, not swords.
"My conviction is that healing is less about battling illness and more about nourishing life," says David Servan-Schreiber, M.D., Ph.D., author of the best-selling "Anticancer: A New Way of Life."
Servan-Schreiber, a neuroscientist, helped usher in the use of cutting-edge technology to catch images of the brain in the act of thinking, and his expertise around cancer and healing comes from personal as well as clinical experience.
A Surprising Discovery
Eighteen years ago, when a volunteer subject turned out to be a no-show, Servan-Schreiber stepped into an MRI scanner himself -- and discovered his own brain tumor.
Surgery and chemotherapy helped him into remission, but when he asked his oncologist what he could do to help prevent a relapse, his doctor had no answer. So he dedicated himself to learning how diet and lifestyle changes could boost his inner healing resources. (His cancer remains in remission today.)
"We all have natural mechanisms for ongoing healing in our bodies," he explains, and conducting our everyday lives in ways that nurture those mechanisms is a key part of preventing and recovering from illness.
Not to say that conventional medicine doesn't have its place -- especially when it comes to cancer. "You cannot replace chemotherapy with broccoli, jogging, and meditation," he says, "but it's clear that those three things change the way your genes control biology."
Nurturing the body's innate healing abilities through lifestyle choices has long been a cornerstone of disciplines such as Traditional Chinese Medicine, says Maoshing Ni, Ph.D., a 38th-generation doctor of Oriental medicine, cofounder of the Tao of Wellness center in Los Angeles, and the author of "Secrets of Self-Healing" and other books.
"We are trying to avoid waging war," he says. "The idea is to maintain a state of harmony so we don't have to send in the troops."
Even healing from a cut isn't just a matter of isolated tissues knitting back together. As soon as you nick your hand, several systems launch into action: The clotting system of the blood immediately forms a fibrin clot to stop the bleeding. The circulatory and cardiovascular systems start delivering white blood cells to fend off bacteria and protect the wound from infection while also delivering cells called fibroblasts, which lay down collagen to aid in tissue repair.
And the stress response kicks in, controlling the normal operations of the body -- such as inflammation, digestion, and elimination -- to divert resources (like blood flow) toward the crisis.
So not only is healing happening all the time, it's also happening all over the body, which is why you can do more to aid the healing of a cut than slap on a bandage.
Research shows, for example, that good nutrition speeds wound healing and that moderate exercise can aid in circulation (which brings in oxygen and nutrients and washes out toxins).
As a neuroimmunologist, Esther Sternberg, M.D., author of "Healing Spaces: The Science of Place and Well-Being," was well-versed in the biological underpinnings of healing.
She'd spent her career studying the seminal links between stress in the brain, inflammation, and rheumatoid arthritis. And then she developed inflammatory arthritis, a similar condition, herself.
Sternberg blames a taxing combination of stress from long hours in the lab and grief over her mother's death for triggering her own illness. It was only when she accepted an invitation to spend some time at a friend's home in Greece that she learned firsthand the effects of destressing on mind and body.
After just a few days of long walks through the countryside, delicious, fresh Mediterranean food, and plenty of rest, she noticed improvements in her condition that surprised her.
"I was watching some fishermen down on their boats one afternoon, and I felt how connected they were to the rhythms of the sun and the sea," she recalls. "That was the moment when I realized I'd been doing it all wrong. I needed to change my way of living if I was going to continue to get better."
This profound personal experience not only informed her own health, but changed the way she viewed healing. "Every moment of the day, we deal with insults to our emotional, physical, and spiritual selves," she explains.
Those insults can come in the form of cuts and scrapes, viruses, allergens, junk food, muscle strains, anxiety, heartbreak, and more. "If you're healing at the same rate as you're being traumatized," Sternberg says, "you don't even realize it's going on. But as long as you're living, you're healing."
Once considered a radical idea in Western medicine, the mind's power over the body has garnered considerable respect over the past couple of decades, thanks to a growing body of neurological research and new technologies, such as functional MRIs.
Researchers have established that biochemicals, released from the brain during various mood states, affect how well the body repairs itself.
Negative feelings (such as anxiety, fear, and loneliness) have been shown to trigger stress hormones such as cortisol and epinephrine, which inhibit the immune system, while positive feelings (like happiness, love, and peacefulness) can boost our healing ability through feel-good neurotransmitters such as dopamine and oxytocin.
The research shows that this isn't all light and fairy dust, either: A study from Pittsburgh's Carnegie Mellon University suggests that positive emotions may aid in warding off the common cold. When 334 quarantined volunteers were infected with a cold virus, those who tended to experience positive emotions (feeling content and relaxed) were more likely to resist infection and avoid developing symptoms than those who tended toward depression, hostility, and anxiety.
Research shows that depression, which affects cortisol levels, can worsen outcomes in patients with cancer and heart disease, while loneliness and social isolation have been linked to weakened immune systems, high blood pressure, and faster progression of Alzheimer's disease.
And a new study from the University of Kentucky has found a correlation between optimism and a process called cell-mediated immunity, which helps prevent viral infections.
Explaining the Placebo Effect
There's perhaps no better proof of the impact of mind over matter than the placebo effect. Studies suggest that it accounts for around 30 percent of the response to any medical intervention and yet has been traditionally dismissed by researchers as some kind of magical thinking. In fact, it's a powerful example of the connection between thoughts, beliefs, and physical healing.
"The placebo effect is not a sham," Sternberg says. "It's evidence that the brain plays a very important role in healing." When we expect a pill or treatment to help us, Sternberg explains, the brain shifts gears, "releasing endorphins and other chemicals that support the immune system in its job."
The great news about healing is that our minds and bodies know intrinsically how to do it -- if only we'd allow them.
"Unfortunately, in the past 60 years or so, we've developed a number of habits that get in the way of our natural healing mechanism," Servan-Schreiber says. Our diet, for instance, has shifted away from whole foods and toward processed nutrient-deficient, low-fiber, high-sugar foods that trigger cellular inflammation, which, he says, "makes it hard for our body's natural defenses to take hold" -- and easier for cancer and other diseases to gain control. Reduced immune function is also associated with a sedentary lifestyle and increased isolation and depression.
"It's not a single stressor that makes you sick," Sternberg says. It's the cumulative effect of many stressors on the body, mind, and spirit that wear you down and make you vulnerable. We consulted a range of experts for their healing strategies and have come up with six key lifestyle changes to keep your self-healing systems vital -- and intact.
1. Ease Stress with Pleasure
When people tell Sternberg that they don't have time to get a massage or sit in the park for lunch, she asks, "Do you have time to be sick?" Relaxation and pleasure are healing states of mind, she says, and if we don't visit them regularly, we compromise the body's ability to recover from its daily traumas.
Anything you can do to reduce your stress response will pay off on the healing front: A 2010 study on post-traumatic stress disorder (PTSD), headed by Columbia University's Mailman School of Public Health, suggests that severe stress can alter one's genetics and affect the body's immune function for years to come. PTSD has long been associated with compromised physical health, including diabetes and heart disease.
Seek out stimulation. Admiring a work of art, listening to music, or tending a garden aren't just extracurriculars but part of a comprehensive health-insurance plan. Sternberg says doing things you enjoy triggers the brain to release feel-good chemicals.
Make love. Not only is sex a fine idea in general, it also replenishes stress-relieving hormones and, according to researchers at Wilkes University in Pennsylvania, beefs up the immune system by increasing levels of the antibody IgA, which protects against colds and other infections. Of 111 subjects, those who reported having sex once or twice a week had higher levels of IgA in their saliva than those who abstained, had sex less than once a week, or had it three times or more. (So there can be too much of a good thing!)
2. Find Something to Believe In
Research indicates that people who have a spiritual faith of some kind are better equipped to deal with illness. A recent study from the University of Miami shows that patients with HIV who described themselves as "spiritual" (meaning they have a sense of peace, faith in God, or a compassionate view of others) showed a higher count of AIDS-fighting CD4 immunity cells and a lower viral load.
A 2006 University of Michigan School of Public Health study headed by sociologist Neal Krause, Ph.D., tracked the health of more than 1,300 older adults across the country, and found that people who believe their lives have meaning live longer.
3. Talk It Out
It's true: Hostility is bad for your health. Studies show it can raise levels of cytokines, behavior-regulating proteins in the immune system that are associated with arthritis, osteoporosis, and other conditions.
A 2005 study from Ohio State University looked at the effect of marital discord on simple wound healing in 42 married couples. Researchers found that couples who "demonstrated consistently higher levels of hostile behaviors" healed 40 percent more slowly from their lab-inflicted blister wounds than the more harmonious couples. When the subjects attended a structured interaction to help moderate conflict, their wound healing improved.
Don't bite your tongue. A 10-year study published in Psychosomatic Medicine found that wives who silenced themselves during arguments with their husbands were four times more likely to die during that period than women who spoke their minds; they were also more likely to suffer from depression and irritable bowel syndrome. Learning conflict resolution skills can help self-silencers to speak up. If you aren't ready to express your problems aloud, get those emotions out some other way: Write them down or even have a private venting session.
"Sleep and immune health are inextricably linked," says sleep expert Rubin Naiman, Ph.D., author of the new audio book "The Yoga of Sleep." Many of the body's major restorative functions --tissue repair, muscle growth, protein synthesis -- happen mostly or exclusively during sleep, and studies have linked sleep deprivation with lowered immune ability and increased obesity and inflammation, all of which are risk factors for heart disease, cancer, and stroke. A 2008 UCLA study found that just one night of interrupted sleep triggered the cellular-inflammation process associated with cardiovascular disease, arthritis, and more. Everyone's sleep needs vary, but most adults require between seven and nine hours per night.
Change your attitude about sleep. "People who sleep well love sleep," Naiman explains. The key then, he says, is falling in love with it. Create a few pleasurable bedtime rituals (take a hot bath with lavender oil, turn off electronics). Skip the nightly glass of Pinot, though, as alcohol before bed tends to increase wakefulness during the night.
Breathe before bed. Naiman recommends the 4-7-8 breathing exercise to induce relaxation. Lying in bed, breathe in through the nose for a count of 4, then hold the breath for 7, and slowly exhale through the mouth for 8. Repeat 3 times.
Say "Om." A regular daily yoga practice may also reduce stress and encourage better sleep. One new study shows that cancer survivors who practiced gentle yoga twice a week reported a 22 percent improvement in sleep quality and cut their use of sleep medication by an average of 21 percent.
5. Eat Plenty of Healing Foods
Create an inner healing environment by feeding your body nutrients that boost immune function and lower inflammation. Nutritionist and naturopathic doctor Cathy Wong, author of "The Inside-Out Diet," offers her favorites:
Get your fruits and veggies. No surprise here: A range of colorful fruits and vegetables provides you with vitamins and minerals, plus disease- fighting antioxidants. Try apples, oranges, tomatoes, berries, and dark-green vegetables (broccoli, kale, collard greens).
Enhance your immunity. Protein provides the amino acids that are the building blocks of the immune system; lean meat also contains iron, zinc, and vitamins B6 and B12. Try wild salmon and lean turkey and chicken; vegetarian options include beans and legumes (lentils, chickpeas, kidney beans), nuts, and seeds (try sunflower and pumpkin).
Turn down the sugar dial. Opt for foods low in sugar to help reduce inflammation, such as artichokes, oatmeal, brown rice, and beans, which have a high ratio of fiber to sugar. Try a natural sweetener such as stevia, which has a more muted effect on blood-glucose levels than cane sugar or even honey.
Get enough good bugs. he gastrointestinal tract plays a critical role in the immune response because its large surface area comes into contact with so many microorganisms and potential pathogens. Eating fermented foods promotes beneficial bacteria, or probiotics, in the digestive system, crowding out disease-causing bacteria and keeping them out of the bloodstream. Add fermented foods to your diet by eating yogurt, kefir, miso, tempeh, and even (unpasteurized) pickles and sauerkraut.
6. Move It
It's hard to overstate the benefits of being physically fit: Regular moderate exercise promotes circulation, strengthens heart muscles, and increases nutrient delivery and oxygenation of cells -- all of which are critical for healthy immune function. New genetic studies also suggest that exercise helps keep cells healthy by protecting the telomeres, or tips of DNA, that are involved with gene replication. But there's another healing aspect of exercise that Eastern cultures recognize. "In Chinese medicine, exercise is considered an activation of chi, or energy flow, which can, in turn, improve one's ability to fight disease and heal," Ni says.
Keep It short and sweet. For the best results and the least wear and tear on muscles and joints, try working out in frequent, shorter sessions (say, 30 minutes of walking, dancing, yoga, or other mild aerobic exercise three to four times a week) rather than marathon workouts once or twice a week. In terms of immunity, it's just as important not to overdo it: "You'll know you've overexercised if you're exhausted after each workout, get frequent colds and flus, or are always in pain due to your effort," Ni says.
Take it slow. Ni is especially fond of tai chi and qigong -- ancient Chinese practices that combine slow, controlled movements and breathing exercises to encourage the flow of qi. A recent University of Sydney study found that cancer patients who practiced qigong had lower inflammation levels and improved mood -- both factors in healing. And a University of Illinois study of healthy older adults found that those who spent five months doing a combined tai chi and qigong practice responded better to flu vaccines and had more antibodies in blood tests.
© 2014 Martha Stewart Living Omnimedia. All rights reserved.