Cold and flu viruses are all around us all the time. In the winter, close overheated rooms inside and wet cold weather outside conspire to make these viruses easier to catch.
There are valid ways to reduce your exposure to cold and flu viruses, but focusing excessively on these techniques could render one obsessive-compulsive. Cold and flu viruses spread mainly via the hands, so anywhere lots of hands touch is bound to be contaminated. Think public restrooms, public transportation, stores, restaurants, ATM keypads, money, and library books: the list is endless. Even inside the cleanest home, germs abound. One widely distributed study found far more disease-causing microorganisms on kitchen faucets than on toilet seats. Frequent hand-washing certainly protects against infection. But unless you closet yourself away, Howard Hughes style, there's no way to avoid cold and flu viruses.
What you can do is strengthen your body's defenses against them. Our immune systems are constantly at work, protecting our bodies against invaders. When we get sick with an infectious illness, it's less a comment on the virulence of the "bug" and more a comment on a breakdown of our immune system.
Emotional stress and fatigue lower our defenses. The neurotransmitters that affect our emotions have receptors all over the body, not just in the brain. Interestingly, grandma was also right about "catching a chill." While cold weather does not cause illness per se, lowered body temperature renders people more susceptible to infection. Cold elsewhere in the body (especially the feet) constricts blood vessels in the nose, shutting off the supply of white blood cells needed to fight off invading germs.
During stressful times, it's especially important to pay close attention to your diet. Most vitamins and minerals play some role in strengthening the immune system, so that old boring chestnut, a balanced diet of whole foods, still comes into play here. Vitamin C plays an especially important role, strengthening the immune system in many capacities. As is true with most nutrients, vitamin C is best absorbed in its natural state, from food. Citrus fruits, broccoli, brussel sprouts, and peppers are the best sources, but all fruits and vegetables contribute some vitamin C, along with valuable phytochemicals and fiber. However, it is difficult to consume all the vitamin C one needs to fight the stresses of the modern world from diet alone. Recommendations for optimal vitamin C intake vary widely. I recommend a 1000 mg supplement daily, increasing that to 2000-3000 mg in times of unusual stress. The body will excrete any vitamin C it doesn't need.
Zinc is another general immune system strengthener. Good food sources include whole grains, lean beef, shellfish (especially oysters), and milk. Supplements over 50 mg/day actually suppress the immune system. However, zinc lozenges, sucked on every two hours at the first sign of a cold, may decrease the severity of the symptoms.
Garlic also enhances the immune system, but you need to eat the equivalent of half a clove of raw garlic per day to get the benefits. If you feel like preserving your breath, try aged garlic extract (600mg/day).
Chili peppers are potent antibacterials (a good reason to eat salsa in Mexico). They also appear to protect against viral illnesses, but whether this is a result of the hot pepper compound (capsaicin) their high vitamin C levels, or some unknown factor is unclear. Certainly, eating hot peppers will clear your sinuses when they are congested. Horseradish (including Japanese wasabi) has the same effect.
Echinacea, a member of the daisy family, increases the production of white blood cells. Whether it actually prevents infection or shortens the duration of a cold remains a matter of debate. People with allergies to the daisy family or who have autoimmune disorders such as lupus, MS, or HIV should not take Echinacea. Astragalus, a traditional Chinese medicine, also strengthens white blood cells. Elderberry extract (a vitamin C rich relative of blueberries) also helps in some cases.
People have known about the infection-fighting properties of chicken soup for a long time. Ancient Greek and Egyptian treatises recommended chicken soup to treat respiratory disorders, and the 12th century physician and scholar Moses Maimonides wrote that chicken soup alleviated symptoms of colds, flu, and asthma. Modern research bears this out. During a respiratory infection membranes of the nose, throat, and sinuses swell, more as a reaction to the invader than as part of the disease process itself. Chicken soup temporarily blocks the movement of inflammation-causing white blood cells into the membranes as well as reducing congestion via steam. Vegetable rich soup appears to be more potent.
Probiotics are small microorganisms that help maintain the normal balance of microflora in the intestine. A healthy array of the 400-some "good" bacteria in the intestine are needed to keep bad invaders at bay. Probiotics are known to protect against gastrointestinal illness, bladder and vaginal yeast infections, but it appears they may protect against respiratory infections as well. The body is a holistic system: what affects one part of the body has a ripple effect elsewhere. A study in Sweden, (admittedly funded by lactobacillus supplement producers) showed that workers who took this probiotic took less than half the sick days than those who did not. Optimally, you should get your probiotics from whole foods rather than supplements. Unpasteurized yogurt is especially effective, and raw milk cheese also has the same effect. Cider vinegar and brewers yeast fit the probiotic definition - so do pickled foods. In an interesting study, scientists fed kimchee pickles to 13 birds with avian flu and found that 11 recovered! In Korea, where kimchee pickles have traditionally been valued for their health benefits, farmers routinely add the kimchee bacterium to animal feed.
If, despite your best efforts, you come down with a cold or flu this winter, try and take it easy. These illnesses are most infectious during their first 48 hours and coming to work only spreads the germs around. Continue your same nutritional program, perhaps increasing your intake of vitamin C and adding some Echinacea and zinc lozenges. Rest and drink plenty of fluid, which clears your body of toxins and congestion. Avoid drugstore decongestants. They might make you feel minimally better, but they mask symptoms without doing anything to boost your immune system.
Wendy Gordon is a writer and restaurant reviewer who lives in Portland, Oregon. She has a Masters Degree in Clinical Nutrition from the University of Chicago, and is on the Board of Directors of Food Front Grocery, a co-op in Portland.