PREVENTION June 2008 Best Brain Boosters After 55 Eight really easy ways tokeep your mind sharp, healthy and focused

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Sure, you blank on a name now and then, and sometimes you can’t remember where you put your keys. But that doesn’t mean your steel-trap mind is doomed to turn into a colander as you get older. “You can build up your brain, just like a muscle,” says Stephen Kritchevsky, PhD, director of the Sticht Center on Aging at Wake Forest University Baptist Medical Center in Winston-Salem, N.C. Researchers haven’t yet found a way to prevent all age-related decline and Alzheimer’s disease, but they have uncovered plenty of defenses against the mental missteps we all experience. Just doing a few simple things, like ordering the fish special or tidying up your house, can yield big results. Read on for new strategies that can help you keep your brain nimble, your memory sharp, and your keys always in the place you know you left them.

Test Your Hearing
If you’re one of the 31 million Americans experiencing hearing problems, your memory may be suffering, as well. New research from Brandeis University shows that people with mild-to-moderate hearing loss may need to expend so much cognitive energy to hear what’s being said that they’re unable to remember it afterwards. Other research has shown that older people with hearing loss have trouble comprehending more complex sentences, especially when they’re spoken quickly. “As we age, our brains change in the way they perceive and encode information,” explains Mike Merzenich, PhD, a professor at the University of California San Francisco. Hearing is an increasingly important part of that process, so it’s imperative to keep yours healthy.
Try This: Have your hearing tested every 3 years after age 50. And prevent further hearing loss by turning down the volume on your television and stereo. If you use an MP player, make sure that you set it to no higher than 80% of the maximum.

Keep Your BMI Below 25
Being overweight can significantly impact brain function as you age, and several studies have tied a high Body Mass Index (BMI) to poor cognitive function in middle-aged and older adults (a BMI of between 18.5 and 25 is considered healthy). In memory recall tests, people with a BMI of 20 remembered an average of nine out of 16 words, while people with a BMI of 30 remembered just seven. A higher BMI was also associated with more pronounced cognitive decline over that study’s five-year period. And it’s not just very heavy people who should be concerned: In another study, researchers found that people with BMIs between 25 and 30 at midlife were twice as likely as people at a healthy weight of developing Alzheimer’s or another form of dementia (people with a BMI of 30 or higher were three to five times more susceptible).

Try This: You can determine your BMI at prevention.com/bmicalculator. If your BMI is over 25, make it your mission to lose 5 to 7% of your body weight. Try cutting 250 calories a day from your diet and burning an extra 250 calories through exercise.

Eat Salad Every Day
According to a new study conducted at Chicago’s Rush University and published last year in the journal Neurology, people who consume about three servings of vegetables a day reduce their cognitive decline by roughly 40 percent, making them the mental equals of people five years younger. Green leafy vegetables seemed to have the strongest effect, and researchers theorized that it might be due to the veggies’ vitamin E. Earlier research shows that vitamins B12 and folate, also found in leafy greens, may have similar brain-boosting power.
Try This: Add Vitamin E-rich spinach, almonds, or sunflower seeds to your bowl for an ever smarter salad.

Pay (Better) Attention
As you get older, your brain becomes less efficient at sifting through different sources of information. This means it categorizes everything — what you see and what you hear, for example — into one big message. Known as sensory integration, this tendency can make it harder to block out distractions and focus on what’s important, like a story you’re telling or a task you’re trying to accomplish. The answer, says Kritchevsky, could be exercises that force you to focus on a single task while ignoring everything else. In a recent study, participants were asked to perform a visual test — pick out certain letters among an array of them — while ignoring superfluous sounds. Those who had completed an attention-training course had higher scores, and brain scans revealed that they were better able to recruit the grey matter required for the test (the visual cortices of their brains) and temporarily turn off the non-essential auditory regions. The key is not so much what you do as how much attention you give it — meaning if it’s something you can do it on auto-pilot, it doesn’t count. It’s only when you actively focus on one activity that you train your brain to perform better.
Try This: Play word games and puzzles like Sudoku, which demand your attention and build your concentration — and thus can help reduce that sensory hodgepodge and keep your thinking sharp. Or go to prevention.com/brainfitness to find more brain-boosting games.

Order the Fish
A Norwegian study found that older people who eat any type of fish — fatty fish, lean fish, even fish sticks — score significantly better on memory, visual conception and other cognitive tests than those who skip the seafood. And while earlier research has focused on the impact of Omega 3 fatty acids, the jury is still out on what components of fish have the most brain-boosting power, says David Smith, FMedSci, Professor Emeritus of Pharmacology at the University of Oxford and one of the study’s co-authors. “The fact that we found that lean white fish was as good as fatty fish suggests that it is more than the Omega-3s. Fish are rich in other substances that might be important, such as niacin and taurine.”
Try This: Eat two fish dishes every week. If you’re not a seafood fan, experiment with mild, non-fishy-tasting varieties such as tilapia, scallops, or shrimp.

Check Your Blood Sugar
A new study shows that women with chronically elevated blood sugar have an increased risk of mild cognitive impairment or dementia — even if they’re not diabetics. “There are at least ten possible explanations for this effect,” says Elizabeth Barrett-Connor, MD, a professor at the University of California San Diego School of Medicine and co-author of the study. Perpetually high blood sugar may cause brain or blood vessel damage; there’s also a possible connection between the insulin-degrading enzyme in glucose and the development of Alzheimer's. In fact, adult diabetics can experience a measurable decline in memory function immediately after eating a meal that includes simple carbohydrates, which can cause a spike in insulin levels. If you’re not a diabetic, have your blood sugar checked regularly. And if you are, be especially careful to keep your insulin levels under control.
Try This: Take a 30-minute walk. Muscles must burn glucose for fuel, and that stabilizes blood sugar levels. Eat four to six small meals a day. This also keeps your blood sugar on an even keel.

Make like a Boy Scout
Being conscientious — a self-disciplined, scrupulous, dependable individual — will win you lots of friends (and promotions) and probably preserve your mental capabilities, too. Researchers recently found that conscientious people, those who were goal-orientated and able to control their impulses, showed less cognitive decline and Alzheimer’s disease symptoms. The researchers noted that conscientiousness often accompanies personality traits like resilience and healthy coping, both of which seem to protect people from chronic psychological stress, which has been tied to dementia.
Try This: To nurture conscientiousness, make it a habit to spend 20 minutes a day tidying up the house, suggests Brent Roberts, PhD, a psychology professor at the University of Illinois at Urbana-Champaign.

Eat for Lower BP
High blood pressure puts you at higher-than-normal risk for mental decline. A recent study found that people who developed hypertension in their 40s or 50s were 40 percent more likely to develop some type of cognitive impairment later in life, and were 70 percent more likely to develop what’s known as non-amnestic, or vascular, cognitive impairment. “We know that the brain naturally shrinks with age, but hypertension can speed the process,” Kritchevsky says. Scientists aren’t sure of the exact mechanism, but theorize that high blood pressure might inhibit blood flow or cause damage to the blood vessels in the brain. Other research shows that hypertensive people must use more brain tissue (and thus require more coordinated blood flow) in order to perform the same memory tasks that people with normal blood pressure can do.
Try This: Consume at least three servings of calcium-rich foods daily. Doing so slashes your risk of developing hypertension.

GLAMOUR May 2003 What Really Happens to Your Body When…

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… You’ve got butterflies in your stomach
Feeling worried? You may instinctively react by taking more shallow, frequent breaths. This creates tension in the muscles in your upper gastrointestinal tract, which can irritate your stomach. If you’re very upset, those muscles can start to “flutter,” making you feel a little queasy. In fact, studies have shown that many people seeking treatment for nausea are actually suffering from anxiety, not indigestion. And the queasy feeling generally passes as soon as the worry does.

… You’ve got a broken heart
The initial stress of a breakup can cause the release of hormones, such as adrenaline, that increase your heart rate, tighten the muscles around your rib cage and constrict your breathing — which is why, in the days afterward, you may feel as if your chest is literally being crushed, explains Edward Bruce Bynum, Ph.D., director of behavioral medicine at the University of Massachusetts Health Services in Amherst. In fact, research in the Netherlands shows that about 30 percent of patients who see a cardiologist for the first time with complaints of chest pain are really feeling anxious or depressed.
When you’re feeling broken-hearted, the best way to pick yourself up emotionally and physically is to focus on – yes— moving on. “If you ruminate on the pain and withdraw from others,” says Bynum, “you’re unconsciously telling your body to remain in crisis mode – and feel terrible longer.”

… You’re on pins and needles
“You often get this sensation when you’re anticipating an important event,. such as a big date or a job interview,” says James Overholser, Ph.D., a professor of psychology at Case Western Reserve University in Cleveland. The anxiety causes a slight decrease in blood flow to your extremities, leading to numbness. “It’s the same tingly feeling you get when your foot falls asleep,” adds Bynum. And it typically passes as soon as the anticipated event is over.

… Your blood is boiling
“When you’re mad, high levels of the stress hormone adrenaline surge through your body, rushing extra blood and several other hormones to the vessels near the surface of your skin.,” says Bynum. “This can actually raise your body temperature slightly.” Your heart might also start to beat faster, leaving you a little sweaty and out of breath. Happily, you won’t be hot under the collar forever – only as long as you’re feeling angry.

BOSTON magazine February 2001 Baby Steps Boston gives birth to new advances in prenatal care

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Pregnancy is a time of anticipation. And for many parents, it's also a time of worry, mostly over the health of the unborn child. But Boston's medical establishment is on the cutting edge of advances that can allay expectant parents’ fears over the congenital abnormalities and diseases that can be passed down to new generations. No test yet exists to screen for all problems, but there are a few specific exams that parents can now utilize. For example, a new procedure to check for Down syndrome is being tried at the New England Medical Center, part of a national study sponsored by the National Institutes of Health.

Down syndrome is a congenital disorder caused by a chromosome abnormality that can result in mental retardation, heart defects, and an increased incidence of acute leukemia, among other complications. The new process allows women to be examined at a much earlier point in their pregnancies with what is hoped to be greater accuracy than ever before, using both a first-trimester ultrasound and a maternal blood test to search for signs that a fetus may carry Down syndrome. It also is designed to reduce the need for women to undergo a stressful amniocentesis procedure.

The first-trimester ultrasound examines the skin thickness on the baby's neck, the point where developmental abnormalities linked to Down syndrome can be detected. Later on, a second-trimester test is done on the mother's blood, screening for Down syndrome-related chemicals, many of which are not considered in the standard blood tests used at most hospitals. The combination of these two tests hopefully will allow for earlier detection of Down syndrome, says Sabrina Craigo, an assistant professor of obstetrics and gynecology at Tufts School of Medicine and director of the division of maternal/fetal medicine at New England Medical Center.

Another new procedure at NEMC involves multiple pregnancies, which are especially common in this area now that Massachusetts and Rhode Island, insurance companies are covering infertility treatments. The test screens embryos for a variety of health problems before they are implanted into the woman's uterus – in fact, it can be performed when the fetuses still consist of only a few cells, says Craigo – thus preventing potential life-threatening complications for a woman carrying a fetus with significant health problems.

Of course, all of these procedures are part of the growing trend in medicine of using genetic information to fight – and even prevent – disease. “Right now, we are learning more and more about the relationship between genetics and disease, and the potential benefit of that knowledge is simply enormous,” says Cynthia Fisher, president and founder of ViaCell, a Boston-based cellular pharmaceuticals company.

One division of ViaCell, ViaCord, provides a service known as cord-blood banking, which allows parents to collect and store blood from a baby's umbilical cord immediately after delivery. Cord blood contains a unique type of tissue called stem cells, which have the ability to treat disease in both the child from which they are taken and in members of the child's immediate family.

“Stem cells are incredible,” says Fisher. “They are naïve, meaning they can adapt to many different roles within the human body.” When transplanted, stem cells can morph into marrow, blood, and even bone cells, meaning they can help the body fight almost any kind of disease. “They have what's called a homing mechanism, which tells them to head to the part of the body where they're needed,” she says. Once there, the cells reproduce at an astonishing rate – in fact, cord blood can grow to equal more than ten times the volume of another material that might be used to treat the same condition. Thus, doctors can use 1/10 the amount stem cells vs. what they'd need in a standard transplant procedure.

The implications of stem cell research are huge. Cord-blood banking could put an end to the grueling ordeal of having bone marrow harvested for transplantation. And because the cells are taken from a newborn's umbilical cord, now obsolete, there's no risk or pain involved. And because they can be stored for many years, stem cells retain their ability to treat genetic diseases like leukemia, which might develop years down the road in the baby or other family members. And this isn't science fiction. ViaCord already has undertaken six stem cell transplants, all of which involved siblings of the donor. In one case, an eight-year-old Boston girl, who was undergoing chemotherapy and radiation to treat sickle cell anemia, got a dose of her baby brother's cord blood. She now is free of the disease.

While these treatments still aren't widely available, they are gaining acceptance. Parents who opt to have their baby's cord blood harvested pay $1500, plus $95 per year in storage fees. Once the blood is collected in the delivery room, it's flown to a ViaCord lab in Cincinnati, where it is processed and frozen. The company has collected more than 6,000 samples so far, which it will store under the parents’ name for 18 years; at that time, it can be transferred to the child, who can decide whether to keep it in cold storage.

NEW WOMAN December 1999 Natural Cold and Flu Remedies That Work Five top alternative-health experts reveal which all-natural remedies they recommend — and use themselves

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When you make your drugstore run for antihistamines, decongestants and Kleenex to prepare for the upcoming cold and flu season, you might want to consider stopping at the health food store, too. More and more studies are showing that natural remedies — including good old-fashioned chicken soup — can treat these viruses and even prevent you from getting sick in the first place.

But how can natural remedies possibly fight colds and flu when scientists have spent decades and millions trying to formulate drugs to do the job? Alternative-medicine experts say a number of therapies can do a lot to boost your body's immunity, which helps you resist infection and fight off cold and flu bugs. Over-the-counter drugs, on the other hand, merely treat symptoms, which might not be the best way to go: mucus, coughs and sneezes carry away germs, and fevers slow virus reproduction, so suppressing them may actually make it more difficult to stay healthy. But if you're wary of choosing among the many herbs and elixirs you've seen, relax. We asked five leading alternative-health experts to tell us their favorite natural remedies for colds and flu. Here's what we learned:

Andrew Weil, MD, is one of the country's most prominent natural-medicine experts. He's director of the Program in Integrative Medicine at the University of Arizona and author of the bestseller 8 Weeks to Optimum Health. Dr. Weil's first recommendation: Take 200 mg of vitamin C daily. And during cold and flu season, he suggests an antioxidant cocktail that includes vitamin C plus 400 to 800 IU of vitamin E (400 if you're under 40; 800 if your over 40); 200 to 300 mcg of selenium; and 25,000 IU of a carotenoid supplement with both alpha- and beta-carotene.
If you're on the verge of getting sick, Dr. Weil advises eating raw garlic for its immune-boosting chemicals. To prevent dragon breath, crush the garlic, then mix it with a tablespoon of applesauce and swallow without chewing. "I'd also take several doses of liquid echinacea throughout the day," he says. Mixing it into a small amount of tea or water will make the herb easier to swallow.

Beyond supplements and herbs, Dr. Weil recommends keeping stress in check. Research has shown that tension can actually increase the likelihood that you'll get sick. One simple, inexpensive outlet: writing regularly in a journal. A study found that writing about pent-up emotions helps reduce stress and, therefore, illness. Sit in a quiet place once a day and write for 20 minutes; don't worry about your spelling or even making sense — the only goal is to relieve your frustrations.

Christiane Northrup, MD, is a clinical assistant professor of obstetrics and gynecology at the University of Vermont College of Medicine and a frequent speaker on women's health issues. Her best-selling book, Women's Bodies, Women's Wisdom, focuses on integrating Western and Eastern approaches to health. "The minute I feel a cold coming on, I grab the zinc," says Dr. Northrup. Choose homeopathically prepared zinc lozenges, she says, and don't chew them; sucking allows for better absorption. Dr. Northrup also swears by vitamin C. (Opt for ascorbic acid, which does a better job of stopping cold symptoms than ascorbate.)

This cold and flu season, Dr. Northrup says she's also got a new weapon — an herb called Kan Jang (Andrographis paniculata), which in clinical trials cut patients' chances of getting a cold in half. "I'm taking 300 mg a day throughout the cold season," she says. Keep in mind, however, that conclusive studies have not yet proven the herb's effectiveness.
What should you do if all your illness-fighting attempts fail? After all, sometimes you get sick a matter what you try. "When that happens to me," says Dr. Northrup, "I figure that my body just wants me to rest, so I get into bed, pull the covers over my head, and go to sleep."

Mark Blumenthal is the founder and executive director of the American Botanical Council, a not-for-profit organization that studies plant-based medicine in Austin, Texas. At the top of Blumenthal's list is echinacea, which you should take at the first sign of cold symptoms (for dosage, consult the product package). "Several studies have shown that echinacea can reduce the duration and severity of cold symptoms by 30 to 40 percent," he says. Just don't take it all winter long in the hope that it will act as a preventive — it won't.

What's unique about echinacea is that all the parts of the plant — roots, leaves and flowers — and all three of the herb's species (Echinacea purpurea, E. angustifolia and E. pallida) are effective symptom relievers. "When I first feel a scratchy throat coming on, I take two to three droppersfull of liquid extract (made from the purpurea and angustifolia species) every few hours," says Blumenthal. "By the next day the scratching this is gone." Another remedy he recommends taking at the onset of symptoms is the Chinese herbal astragalus (Astragalus membranaceus), also an immune-system stimulant. Use the liquid form of the herb and carefully follow the label instructions for dosage.

If you still get sick, Blumenthal advises drinking lots of water and taking hot baths spiked with herbal oils like menthol, peppermint, or wintergreen (dilute a few drops of the oil in a tablespoon of olive oil before adding it to your bath). A steamy soak will relieve congestion and, according to some theories, detoxify your body by encouraging perspiration and muscle relaxation.

Harriet Beinfield is an acupuncturist in San Francisco and co-author of Between Heaven and Earth: A Guide to Chinese Medicine. For flu-related chills, she says, make a batch of chicken soup using ginger, scallions and rice noodles, all of which are considered healing because they're warming, explains Beinfield. "The soup helps to increase circulation and supports your body's chi, or life force. This gets rid of an infection more quickly." Make sure that whatever you drink is warm, too. "Think of your digestion as a furnace," she says. "If you make it hard for the furnace to work by drinking lots of cold fluids, you'll just put more stress on your system."

Acupuncture and acupressure can also be used to treat colds. Healers in traditional Chinese medicine believe that stimulating specific pressure points adjusts the circulation of chi so that health is restored. For a cold, use your fingers to find the acupressure point on the top of your hand in the fleshy hollow between your thumb and index finger. Press firmly on the most sensitive spot there, making a tiny circle and maintaining pressure for as long as it feels good. Do as often as you can throughout the day.

James A. Duke, PhD, a premiere authority on medicinal plants, is the author of The Green Pharmacy and Dr. Duke's Essential Herbs. "When colds and flu are going around," says Duke, "I drink lots of spicy soups and teas made with ginger, hot peppers, garlic, and lemon juice, which have been shown to have an antimicrobial effect, meaning they can kill infection-causing germs." For a bad cough, he suggests brewing a comforting tea made by steeping anise, fennel, peppermint, or thyme. And licorice, he says, can help soothe sore throats: "You can find licorice in cough drops, although I sometimes just chew on the root," says Duke. Another effective herb is elderberry (Sambucus nigra), which is said to battle viral infections and even eliminate symptoms in as little as 24 hours. It's sold as a liquid remedy and can help get rid of a cold that's already established itself.

WALKING November/December 1999 Sick of Getting Sick? Here are nine ways to increase your odds of staying healthy through the winter

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Your spouse is sneezing. Half your office has called in sick. Americans suffer more than 100 million cases of cold and flu in a typical year. Will the next one be yours? The truth is, whether or not you'll get any type of infection is hard to predict, and colds and flu are the hardest. You can shun all public places, load up on the supplements, and drink herbal tea—alone—till springtime. Or you can try denial: Go about your life as usual, telling everybody that you simply can't get sick, you're far too busy. Either way, the sniffles could start. No wonder we spend $3 billion a year on over-the-counter cold medicines—and read magazine articles on improving our immunity.

Whether or not you get sick with a cold or the flu, exactly how sick you get and how long you stay that way is the product of many factors, says James F. Jones, MD, a senior staff physician at the National Jewish Medical and Research Center and professor at the University of Colorado School of Medicine in Denver. First of all, you have to be exposed to a pathogen—bacteria or viruses, in this case. The most common pattern of transmission goes like this: Someone has a cold, they sneeze or wipe their nose, then shake hands with someone or touch something—like a doorknob or a countertop. Now you take your just-shaken hand or touch that doorknob or countertop, then unconsciously touch your own eyes or nose.

The next consideration is the nature of the bug you've just encountered. Some infectious agents are fairly innocuous, creating almost unnoticeable symptoms, while others will leave you in bed with a raging fever for several days. Then there's the condition of the host (that's you) at the time of exposure. If you're otherwise healthy and your immunity is working as it should, you might meet the germs, have a brief encounter, and send them packing. But if you are not taking proper care of your health, you're a better host -- basically a germ motel with free cable and a neon "Vacancy" sign. Every germ that goes by is going to want to stop and give you all the worst symptoms it can deliver.

But before you rush out to buy the latest supplement promising superhuman immunity, consider the bigger picture. The immune system is incredibly complex, with layer upon layer of specific and nonspecific responses to all sorts of invaders. Immunity is like the defenses of a country, says Edward Chapnick, MD, an infectious diseases specialist at Maimonides Medical Center in Brooklyn, NY You've got the various branches—army, navy, and so on, each defending its own territory in its own way. So staying healthy isn't a question of increasing one action—generating more T-cells, for instance—or even supercharging the entire system. Just as a country can't function if every citizen is in the armed forces, your body couldn't operate with its immunity locked on high.

Nor can you live in a plastic bubble, away from all pathogens, or be immunized against everything infectious, from cold viruses to cancer. But there are some things you can do both to avoid germs and to shore up your immunity by creating optimal overall health. Here are nine rules that can make those colds a little less common.

#1 Don't be too thin
If you're model-skinny, congratulations—and please pass the Sucrets. Women who are maintaining a weight that's too low may be compromising their immunity for two reasons. One, if you're severely restricting fat and/or calories, you're most likely not eating sufficient amounts of food to get the nutrients you need. And two, if you've whittled your body fat down to below the recommended levels, your body may not be able to produce certain immune agents, called complement proteins, which are generated within the fat cells. Even the act of dieting itself has been linked to a decrease in a particular type of immune cells.

None of this is to say that being overweight is a better way to maintain immune health. Obesity is associated with its own type of immune-system inhibition. So what's the answer? Maintaining a healthy weight, says David C. Nieman, a professor of health and exercise science at Appalachian State University who has studied the relationship among exercise, weight, and immunity. If you have pounds to lose, lose them slowly and steadily, and use exercise as well as calorie restriction. Yo-yo dieting and rapid weight loss both are linked to compromised immunity.

#2 Avoid germs, not people
Research shows that strong social ties make for strong immunity. That means staying connected to the outside world despite your fear of the flu.

The trick is to take reasonable precautions without cloistering yourself. Staying far afield of anyone who's coughing, sneezing, or otherwise emitting virus-filled droplets will dramatically reduce your chances of infection. So if someone's got an active infection, keep your interactions to phone calls until she's feeling better. When strangers are involved, remember that it's hand-to-hand transmission that's your biggest concern. And that includes hand-to-inanimate-object-to-hand transactions, too. When you take public transportation, leave on your gloves (or use a handkerchief) to avoid touching surfaces like handrails and hanging straps. When you use a public restroom, keep a paper towel to use when you open the door, then pitch it as you leave. At home, keep your own drinking glass in the bathroom and at the table, and be sure to toss the toothbrush regularly. The most important bit of advice: Wash your hands as often as you can, especially as you're preparing food, which can be contaminated just as easily as any other object.

#3 Sniff out hidden stressors
You can start by eliminating the obvious things, like cigarette smoke (active and passive), full-boil arguments with the kids, and sleepless nights. All of these have been linked to immunity suppression, says Michael F. Roizen, MD, professor of medicine at the University of Chicago School of Medicine and author of Real Age: Are You as Young as You Can Be? (Cliff Street Books, 1999). Now you're ready to look for the less obvious things.

Start with your choice of headgear. Your mother may have nagged you about wearing a hat in the winter, and you might think that being all grown up means you can skip the cap. Wrong. Having a cold head won't give you a cold, but allowing your body temperature to drop (something that happens quite easily when you walk around bareheaded this time of year) can make your body more accommodating to viruses. "Respiratory viruses replicate better when the body temperature is lower than normal," says Jones. "Why do you think they call them ‘colds’?" This isn't just a theory: In a recent study that tracked patients recovering from surgery, those who were allowed to get chilled developed more infections than those who were bundled up. Now here's a surprising stressor: sunshine. We've known for some time that UV light contributes to cancer. But now, researchers are finding that sunlight—even in doses too small to create a sunburn—can suppress immunity throughout your body. One theory is that sunlight generates free radicals, which essentially eat up the body's supply of disease-fighting antioxidants. With your antioxidants depleted, you're ripe for any type of infection.

#4 Don't sneeze at vegetables
Yes, you've heard it before, but researchers keep astonishing us with how healthful vegetables are. Veggies contain a vast array of micronutrients that can affect immunity They also contain phytochemicals (plant-based nutrients) that appear to help your body's defenses. Among the most promising: onions and garlic, which contain allicin, a chemical that appears to help ward off infections. Other winners: dark and brightly colored vegetables, which contain carotenoids, plus lots of citrus fruits for the vitamin C.

The goal is to eat a variety of foods, says Susan Adams, MS, RD, a spokeswoman for the American Dietetic Association and a nutrition educator in Seattle. "You can make a big difference in your overall health and in your immunity by making sure you get plenty of fruits and vegetables in your diet," she says. They provide a rich source of antioxidants, including vitamins A, C, and E, plus the minerals zinc and selenium.

#5 Be vitamin savvy
While researchers are nowhere near the point of giving a precise prescription of every nutrient known to fend off the flu, it's clear that many vitamins affect immunity. Among the best researched in terms of a direct link to immune function: C and E. Though C may not be the cold cure-all it's been touted to be (see "Prevention Myths," below), it certainly can help you avoid getting sick. You can take up to 2,000 milligrams of C a day, says Roizen, but many practitioners suggest you stick to 200 to 500 milligrams a day. "There's only so much your body can absorb, so you'll just excrete the excess." You also can take up to 4,000 IU a day of vitamin E, but you should be careful with E. Along with vitamins A and D, E is a fat-soluble vitamin that's are stored in the cells when consumed at levels higher than the body can absorb. Thus, these nutrients can build up to toxic levels (research shows that taking too much vitamin A can actually suppress immunity).

To ensure you're getting the right amounts of your vitamins, take a multi, says David Schardt, an associate nutritionist with the Center for Science in the Public Interest, a Washington, DC, watchdog group. Studies show that taking a daily multi can help some people stave off an infection. Research is still sketchy in this area, he says, but a multivitamin is probably good insurance that you are getting all the nutrients you need—and not overdoing it on any one.

#6 Curb the carbs
Although we all know that exercising demands eating plenty of carbohydrates, eating a diet that's disproportionately heavy on carbs can suppress immunity significantly. Researchers theorize that it's not the carbohydrates themselves that hurt, but the lack of other food types that they replace. There is a clear link between sufficient dietary protein and healthy immunity, and although the general American public shouldn't worry (most of us get twice the protein we need, says Adams), people who eat restricted diets in an effort to lose weight might be cutting themselves short. A healthful daily portion of protein for most women is so to 65 grams a day, says Adams. An egg or an ounce of meat each has seven grams, so it's not hard to get that much every day.

Too many carbs also can mean too little fat. While dietary fat has earned much of its bad reputation, it's still an essential part of any diet. So avoid the saturated fats (in animal products and certain vegetable oils, such as coconut), but keep the polyunsaturated and monounsaturated fats. Olive oil, for example, has myriad health benefits, including improved immune function. Eating enough fat is also essential to allow absorption of fat-soluble vitamins, including cold-fighting vitamin E.

#7 Mind your minerals
Several trace minerals—namely iron, calcium, magnesium, and zinc—have been identified as important to healthy immune functioning.

But taking fistfuls of mineral supplements isn't the answer. As with vitamins, more is definitely not better. For one thing, minerals are notoriously high-maintenance: They have an affinity for certain nutrients and an aversion for others, and it may seem that you need a Ph.D. to figure out which to take and at what time and with what food (and what other nutrients). Example: You should take calcium and magnesium in a ratio of three to one, but you'll have to remember to take your calcium at a time when you're not taking your iron, because it will decrease the iron's absorption. If you take your iron with vitamin C (or wash it down with a glass of orange juice), that will increase its absorption. Magnesium and calcium are a special concern for a lot of people, especially for those who drink more than five cans of soda per day. Some sodas contain a type of phosphorous that can upset the balance of magnesium in the body.

Because minerals are essential for good health, says Adams, the best approach is the most basic: Eat a wide variety of foods, including vegetables, to get the minerals you need. And take a multi with the RDA of the major minerals for good measure. Getting enough iron is especially important for women with heavy menstrual periods, since they may be losing excessive amounts every month.

#8 Work out wisely
Great news for walkers: Ours seems to be the best exercise for keeping immunity high. "We've studied women of all ages, from their 20s to their 70s, and found that those who walk briskly for 40 to 45 minutes a day five days a week, have roughly half the sick days as women who don't walk," says Nieman. The activity appears to increase the number of immune cells circulating in the body. "The immune cells are like cops hanging out at the station," he says. "If they aren't patrolling the streets, then the crooks will have a field day. Walking seems to get the cells out there, like cops on the beat."

But that doesn't mean the more exercise, the better. If you overdo it—the threshold seems to be about 90 minutes, Nieman says—then you'll get the opposite effect, with stress hormone levels going up and circulating immune cells going down. The effect lasts for several hours after the workout. Does this mean you should never exercise longer than 45 minutes? No, says Nieman, who is himself a marathon runner. But be aware that your workouts might be putting a burden on your immune system, and shore up in other areas.

#9 Monitor your mood
Clinical depression and its many cousins, including seasonal affective disorder and the milder, more intermittent bouts of depression that often go undiagnosed, can impair immune function. Chronic stress also can hinder your body's defenses. One recent study found that people with financial worries—and without adequate coping skills—are twice as likely to develop periodontal disease (go figure). "Stress seems to cause a systemic effect," says Robert J. Genco, DDS, Ph.D., chair of the oral biology department at the State University of New York at Buffalo and the study's lead author. "We adjusted for the fact that people under stress might not be taking care of themselves the way they would normally—brushing and flossing, for example," he says. "But stress was still an issue in the people who developed gum disease."

The key, he says, is to recognize stress and to develop coping methods to defuse your worries.
A proven stress-reducer—if perhaps an unusual way to fight colds—is sex. And as long as you know what your partner's exposure has been, research shows that sexual contact isn't as big a risk factor in spreading cold germs as shaking hands. In fact, research has proven that regular intercourse can even improve immune function. So don't shun intimacy. Winters are long and cold enough as it is.