How to be Super Healthy

Eat these foods. Take these pills. Then backs and relax. Your immune system will do the rest.

There was a time not so long ago when people didn't worry much about their immune systems-back when most of us didn't even know we had one. But these days, judging by thc number of immunity-enhancing products flooding thc market, more and more of us are fretting about the state of our defenses against disease. Books like Boost Your Immune System Now! and Supercharge Your Immunity have crowded onto bookstore shelves. Health food stores sell dozens of supplements that purport to boost immunity, from echinacea and ginseng to fancy formulas like Immune-Plus. One concoction, enticingly called Life Extension Mix, claims to contain no less than 56 ingredients that improve immune function, from vitamin A to zinc.

It was AIDS, of course, that made us all aware of the importance of our body's fighting forces. Now, in this era when taking control of our health has become a defining feature of the good life, we think we should be able to make our immune systems invulnerable. Every sore throat becomes a spur to lessen stress or pop the latest pill, every acquaintance's skin cancer or pneumonia a nudge to healthier habits.

But is it really possible to boost the immune system enough to make a noticeable difference in your health? Fifteen years ago scientists generally scoffed at the notion. The immune system was pictured as impervious to influences short of severe malnutrition or a lethal virus like AIDS. Fierce immune warriors with names like natural killer cells and killer T cells were believed to operate entirely on their own, independent of other systems of the body. The notion that seemingly minor influences could affect the battle--a stressful week, a less-than-perfect diet--seemed preposterous.

In recent years, though, researchers have discovered that the immune system is far more intricately linked to the rest of the body, and far more sensitive to fluctuations in our physical and mental states, than anyone had guessed. The battle-hardened fighters, it turns out, have a vulnerable side.

That may sound worrisome, especially in a stressful world where bypassing life's ups and downs is about as realistic as avoiding the freeway. But for anyone looking for new motivation to make healthy changes, there's a big upside, scientists say. Many of the small things we can do for ourselves, like getting a good night's sleep, eating better, or taking time to slow down and relax, can be extremely effective at keeping our defenses from dipping. Even simpler measures may work, too. There's new evidence that popping the right vitamin could go a long way toward keeping immunity strong as we age. And taking certain botanicals may give a flagging immune system a jump-start.

Much of the credit for this new picture of immunity belongs to Edwin Blalock, an immunologist at the University of Alabama at Birmingham. In the early 1980s, he made a curious discovery. Immune cells, he found, can exchange chemical signals with the brain and the endocrine system, which oversees hormone-producing glands in the body. In short order, researchers learned that the brain and the central nervous system can also send and receive signals once thought to be used only by immune cells. "We used to think these systems were completely independent of one another," says Blalock. "Now we know they speak the same language."

In fact, Blalock thinks, the immune system is beginning to look like a sensory organ. "It's really like a sixth sense." Consider what happens when, say, a cold virus enters the body. Even smaller than a living cell, a virus is little more than a strand of DNA or RNA that contains instructions for replicating itself. None of our classic senses can detect it-we can't see, feel, hear, taste, or smell it. But viruses are fiendishly clever saboteurs that can quickly run rampant. Attaching itself to a healthy cell, the germ injects its instructions into the cell and commandeers it. Like a mad scientist bent on cloning himself and taking over the world, the virus turns the cell's machinery to the task of replicating thousands of viruses, which then fan out to infect nearby cells. If the cold bugs are left unchecked, we soon get hit by a runny nose and scratchy throat.

Luckily, a strong immune system is up to the challenge. Unlike most of the body's other major systems, the immune system doesn't reside in a single organ or group of organs, says Steven Mizel, a professor of microbiology and immunology at Wake Forest University School of Medicine in Winston-Salem, North Carolina. Sentry cells are woven throughout our skin, where they detect invaders and then escort them out of the body via the branching network of the lymph system. Lungs and mucous membranes, too, teem with immune cells that gobble up suspicious characters like flu bugs or air pollutants. And T cells throughout the body are equipped to read the precise fingerprints on cell walls that distinguish our own tissue from everything from salmonella bacteria to that fast-multiplying cold virus.

Once immune cells sense a healthy cell has been invaded, they move in for the kill, unleashing a furious attack worthy of Star Wars. Killer T cells attach themselves to infected cells and inject a toxin that destroys cell walls. B cells churn out antibodies, lobster-shaped molecules that glom onto invaders and keep them from latching onto healthy cells. Meanwhile, the brain may trigger a fever, which is thought to boost the activity of immune cells. If the invasion is a serious one, the endocrine system will instruct the body to turn down the sex drive, probably to free up energy for defense. Once the skirmish is won, memory T and B cells stick around, primed to attack the same enemy if it invades again.

That's the war scenario. But most of the time, Blalock now thinks, immune cells are just checking out how we're doing, maintaining the inner status quo, helping the brain and the hormone-producing endocrine system keep tabs. If they sense a surge in stress hormones, for instance, immune cells may report back to the brain, which can send appropriate messages to the endocrine glands to keep the level in check.

It's part of their job description, in other words, to be exquisitely sensitive to even the smallest alterations. This may explain why the stress of an unhappy marriage, the cumulative effect of a bad diet, even a string of sleepless nights can dampen their power. And when immune cells are not functioning as well as usual, they can leave us more vulnerable, too.

"We're really just beginning to understand the complex interactions of these systems and the chemical language that they use," says Blalock. When scientists fully master that language, the ad copy for products promising to supercharge your immunity may not be so farfetched. One day, for instance, it may be possible to take a pill containing the precise chemical mix that puts the immune system on high alert.

In the meantime, we've put together a simple prescription to keep your immune system humming. It's backed by the latest research and packaged into an easy-to-follow plan. Some of it you already know you should be doing. (Now you'll just have a new reason to do it.) But other parts have surprised scientists-and are likely to surprise you, too.

Troublemakers That Steal Your Vitality
Immunity-threatening forces are everywhere in our environment; to maintain healthy defenses, here's what to sidestep.

Cigarette smoke and smog
In addition to its other evils, cigarette smoke can wreak havoc on the immune cells lining the lungs. T cells regularly exposed to smoke gradually become less responsive to invading microbes.

Airborne pollutants found in smog also can hobble the body's defenses, increasing the levels of damaging free radicals in the lungs and impairing the ability of macrophage cells to engulf and destroy inhaled pollutants and dust. Short of moving, it's hard to avoid smog. But if you exercise outdoors, schedule your workouts in the morning, when smog levels are typically lower.

Exposure to sun, whether or not it's enough to give you a burn, can damage immune cells in the skin. And the effect of UV radiation reaches immune cells beyond the burned area. A sunburn on your shoulders, in other words, can weaken immune responsiveness to a cut on your big toe. Sunscreens provide only limited protection to immune cells. For a more complete defense, wear a hat and a long-sleeved shirt, too--or avoid the midday sun altogether.

Toxic chemicals
A variety of pesticides and herbicides, which often leach into water supplies, have been shown to weaken immune cells. An inline water filter can provide some protection. In your own garden, choose nontoxic weed and bug killers. And consider buying organic produce. It carries fewer residues, but more important, creating demand for it encourages farmers to lessen chemical use.

Natural Immune Boosters: 3 That Work
Among the slew of potions vying for space on store shelves, these safe and inexpensive pills offer real benefits to the immune system.

Vitamin E
The best-credentialed remedy
Of all the pills touted for improving the body's immunity, vitamin E has the best record. At Tufts University, Simin Nibkin Meydani divided volunteers into two groups: One received vitamin E supplements, the other a placebo. After 235 days, those who had taken E showed a stronger immune response when their skin was challenged with an irritant. The vitamin E takers also experienced 30 percent fewer infections--the gold standard for evidence. The study looked at volunteers over age 65, when immunity typically declines sharply; no one has studied the effect of vitamin E on younger people. But according to Ranjit Kumar Chandra, a researcher at Memorial University of Newfoundland, even a well-balanced diet barely provides the current Recommended Daily Allowance for vitamin E, so taking a daily supplement may be important at any age to ensure you're getting enough.

A simple fix for an imperfect diet
In a 12-month study with 96 older volunteers, Chandra found that a daily multivitamin-type supplement boosts the number and responsiveness of natural killer cells and certain T cells isolated in blood samples. And that, in turn, seems to make a real difference in health. Volunteers taking the supplement produced more antibodies more quickly and reported fewer infections.

Still the one when a cold strikes
This herb got some bad press last year when a study in which people took it twice daily for 12 weeks found no benefit. But in one German study, people who took echinacea had significantly milder flu-like symptoms .ban those who took a placebo. Other scientists found echinacea takers suffered 36 percent fewer respiratory infections. Echinacea works best when taken at the first sign of a cold; Germany's Commission E, which regulates herbal supplements, recommends taking it for no longer than eight weeks.

3 More With Real Promise
The scientific research on these remedies is still preliminary, but so far the evidence looks good.

The root of a stronger immunity?
At the University of Southern California's School of Pharmacy, researchers found that certain molecules in ginseng spur the body's production of immune-stimulating chemicals like interferon. Chinese researchers from Peking Union Medical College reported last year that ginseng may inhibit the growth of tumors, perhaps by boosting the killing power of immune cells. So far, however, there's no direct evidence in humans that ginseng increases the odds of warding off infections.

Tip of the iceberg of Chinese herbs
In traditional Chinese medicine, dozens of herbs are prized for their potential to strengthen the body's abilities to fight disease. Now researchers are beginning to test their power, and there's tantalizing evidence that some may help. Researchers at the University of Texas M.D. Anderson Cancer Center in Houston discovered that astragalus restored immune function in mice given a powerful immunity-suppressing drug. And in a 1997 study at Hiroshima University School of Medicine, astragalus and another herb, oldenlandia, spurred antibody-producing B cells to multiply in test tubes. Given recent reports warning of contamination of some herbal preparations, however, it's probably wisest to get your herbs through an expert in Chinese medicine.

Medicinal Mushrooms
New Western support for Eastern beliefs
Traditional healers in Asia often turn to mushrooms to bolster the body's resistance to infection. According to a report this year from the University of Haifa in Israel, some 200 species have been found to slow the growth of tumors in petri dishes. Mushrooms also may increase the activity of immune cells that respond to infections, such as killer T cells. At Tufts University in Boston, older mice fed polysaccharides from the mushroom Coriolus showed a more vigorous immune response to foreign substances on their skin. As a result of such findings, researchers have been investigating the potential of nearly a dozen medicinal mushrooms to enhance immunity.

What's Behind the Buzz?
You're certain to hear more and more "scientific evidence" about products that purport to boost immunity. But next time you read an ad or hear the latest from a friend, find out more about the research behind the hype. "Believe me, there's an awful lot of nonsense out there," warns immunologist Steven Mizel. A substance called germanium sesquioxide is still touted as an enhancer of immunity-though the FDA warned in 1997 that it could harm the liver and kidneys. Other products get hyped on the strength of a few preliminary test-tube or animal studies.

Since immune cells are everywhere within us, it's not possible to take a snapshot of the entire system, as with an X-ray. So scientists have to piece together varying types of evidence, some weightier than others. They can test immune cells in a dish, but giving cells in a test tube a sip of herbal tea is very different from drinking some yourself. More convincing is research examining how immune cells in the body respond, as when researchers draw blood before and after a workout. Best of all are studies measuring how well a person's immune system heals a cut, routs germs, or produces antibodies to a vaccine.

If you do your homework and aren't impressed by the results, remember: Stick to the basics, and you're most of the way home.

FIRST THING FIRST Four Essential Steps to Stronger Immunity
Before you reach for a fancy immunity-boosting formula at the health food store, take care of the basics. The following strategies insure the most critical elements of a robust immune system.

1 Eat, drink...
A balanced diet is the single most important factor in maintaining a healthy immune system. According to Simin Nibkin Meydani, professor of nutrition and immunology at Tufts University, deficiencies in any of more than a dozen nutrients--including zinc, vitamin A, and vitamin E--can weaken immune cells. The best advice: Eat fruits and vegetables like leafy greens, oranges, and tomatoes. All are rich in antioxidants that protect immune cells from damage and keep blood vessels elastic, That's right, blood vessels. You might not think of the cardiovascular system as crucial to immunity, but its vessels are the highways immune cells trayel. And go easy on fat. Too much of it not only clogs arteries, but can make it harder for T cells and natural killer cells to fight invading germs. Be sure to drink plenty of water, too. Even mild dehydration can weaken immune cells that line the mouth and sinuses.

2 ... and be merry
An astonishing string of studies over the past several years has shown that your state of mind is a huge factor in determining how well your body staves off illness and heals wounds. When medical students were given a small cut on their skin during the stress of exams, for instance, it took them 40 percent longer to heal than another group of students who were on summer vacation. The immune systems of people undergoing stress of all kinds--from caring for a sick relative to arguing with a spouse--are much slower to produce antibodies when they receive flu or hepatitis B vaccinations.

You can't eliminate stress, of course, says psychologist John Cacioppo of the University of Chicago. But finding ways to deal with it can keep your immune system from becoming run-down. Experiment with deep breathing, meditation, massage, and yoga till you find a form of relaxation that works for you. And don't underestimate the power of time with loved ones; it's a proven way to dampen the immune-weakening effects of stress.

3 Run wild
By now we've all heard that moderate exercise can boost immunity--and that strenuous workouts can cause immune defenses to dip. The latest evidence confirms the value of modest exercise, but hints that vigorous activity may not be so worrisome after all.

Exercise immunologist David Nieman started middle-aged women on a program of brisk walking for 45 minutes a day, five days a week, for three months. The walkers were half as likely as nonexercisers to get colds or the flu. By increasing heart rate and blood flow, Nieman thinks exercise nudges more immune cells into the bloodstream, increasing the likelihood that they'll spot and destroy invaders. In another study, triathletes given a vaccination right after a race responded as strongly as sedentary people, suggesting that the drop-off in blood immune markers seen in earlier studies may not always translate into a greater risk of getting sick.

Just to be safe, here's something you can do if you love a sweat-popping workout: Reach for a sports drink. One reason intense exercise seems to depress immunity (at least temporarily) is that it uses up glucose, an important fuel for immune cells. In a series of 1997 studies, scientists found that drinking a carbohydrate-rich sports drink or fruit beverage before, during, and after a strenuous workout helps replace glucose, keeping immune cell activity from slumping.

4 If you snooze, you can't lose
Burn your candle at both ends and your immune system may begin to flicker. In one study, volunteers kept awake for 40 hours saw their natural killer cell function steadily fall. In another, missing just half a night's sleep caused a significant decline in the activity of these cells, as measured in blood samples. There's no direct evidence that missing out on sleep now and then substantially increases the likelihood of getting sick, says psychiatrist Ruth Benca, a professor at the University of Wisconsin-Madison. But sleepless nights can make people feel more irritable, and that may worsen the immunity-suppressing effects of stress, It's been estimated the average American sleeps 20 percent less today than a century ago. If you're jolted out of a comfortable slumber every morning by your alarm clock, chances are you're shortchanging the sandman. Try going to bed early enough that you awaken on your own.

PHOTOS (COLOR): Going superhealthy


By Peter Jaret

Peter Jaret is a contributing editor.

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