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. Steal these secrets from people who never get sick.
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, drink lots of 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.”