You eat more sweets
'Tis the season for frosted cookies, candy canes, and sugary lattes, but digging into sugar can affect your waistline and your immune system. "There's evidence that sugar consumption lessens our abilities to fight off infections," says Kathryn Boling, MD, a family medicine doctor at Mercy Medical Center in Baltimore. "We put ourselves at increased risk right at the peak of the cold and flu season." While there are ways to boost your immune system naturally, eating simple sugars can halt phagocytosis, a process in which white blood cells attack and engulf viruses and bacteria, by 50 percent. To keep sweets in check, munch on one of these healthy snacks you never need to feel guilty about eating before heading to holiday parties and opt for sugar-free beverages.
You get dehydrated
While cold air doesn't necessarily make you sick, dry winter air can increase your risk of infection. "A virus replicates much more effectively on a dry mucous membrane than it does on a moist mucous membrane, so cold and flu spread like crazy in dry environments," says Dr. Boling. Turn on a humidifier when you go to sleep at night, try these tricks to guarantee you're drinking enough water, and apply moisturizer. "Hydrate inside and out," says Neha Vyas, MD, a family medicine doctor at Cleveland Clinic. "Scratching itchy, dry skin can introduce germs into your body."
You change your sleep schedule
"We go to parties, stay up a little later, and sleep later in the mornings," says Dr. Boling. "That disruption of the sleep routine can be a trigger in people prone to headaches." What's more, the menus at those parties are likely making you succumb to the 8 worst eating habits that affect your sleep. In a University of North Carolina at Chapel Hill study, researchers recruited women being treated for transformed migraine (when occasional migraine progresses to daily migraine). Women randomly assigned healthy sleep habits, such as going to bed at the same time nightly and getting eight hours of sleep, had a 29 percent reduction in headache frequency and 40 percent reduction in headache intensity. Set a reasonable time to hit the sack each night, and stick with it.
You spend more time indoors
This time of year, you may spend extra hours working at your desk to complete projects before vacation, or stay indoors to avoid the cold. "When you're not exposed to sunlight, you tend to sleep more and exercise less, which contribute to a weaker immune system," says Dr. Vyas. Vitamin D levels may also play a role. Vitamin D boosts immune cells' production of microbe-fighting proteins. Adults with low vitamin D levels are likelier to report recently being sick. A Japanese study found that children who took vitamin D pills had a 40 percent lower rate of flu than those who took a placebo. If you're exhibiting the 9 signs you're low on vitamin D, consider popping a vitamin D supplement for an extra immunity boost.
Your tree makes you sneeze
Symptoms that don't improve or worsen over time could be holiday allergies. "Some people are allergic to evergreens," says Dr. Boling. "It may not bother them until they're constantly exposed to the trees during the holidays." Some trees may also harbor microscopic mold spores that trigger sneezing or an itchy nose. If you sniffle around Christmas trees, opt for an artificial tree, or leave a real tree to dry in the garage for a week and shake before bringing it indoors. Don't miss these other surprising ways to stop seasonal allergies in their tracks.
You shop more
Holiday shopping involves handling cash, opening store doors, and using germy ATMs. One British study found that ATMs have nearly the same amount of bacteria that can cause diarrhea and other sicknesses as public toilets. Surprised? Then you need to beware of these everyday items that have more germs than a toilet seat, too. When New York University researchers tested dollar bills, they identified 3,000 types of bacteria, including bacteria that cause gastric ulcers, pneumonia, staph infections, and food poisoning. If possible, keep gloves on when you touch door handles or shopping carts, and wash your hands or use hand sanitizer before you eat lunch at the mall.
You get the holiday blues
It's normal to feel a little lonely amid all the holiday cheer surrounding you. "People who don't have social support systems may watch TV, see families celebrating together, and feel much more isolated and depressed than they do other times of the year," says Dr. Boling. "This causes an increase in the stress hormone cortisol, which suppresses the immune system." If you feel very depressed or are experiencing the hidden warning signs of depression, see a doctor, who may suggest therapy or medication. For a mild case of the blues, try volunteering or reconnecting with friends. It may be just what you need to spark holiday spirit and stay healthy.