Boost your immune system

Bolster your bacteria
Immune-boosting secret Probiotics found in yogourt are the good-cop bacteria that can fight the bad-cop bacteria in the battlefield of your GI tract. New research finds that probiotics can reduce the number of colds you have and how sick you get. In one study, employees who took a daily dose of the good bacteria were less likely to skip work due to colds and other common illnesses. How to get it Not all yogourts are teeming with probiotics. Look for brands that contain live cultures such as Lactobacillus acidophilus or Bifidobacterium. Experts recommend eating a 3/4 cup (175 mL) per day.

Wake up to whey protein Immune-boosting secret Whey, a liquid by-product of cheesemaking, contains a protein-rich compound that builds up resistance by destroying the cell membranes of infectious bacteria. How to get it Visit a natural health store (naturally) and buy some. Dissolve a scoop (30 grams) in water or milk or sneak it into a smoothie every day.

Get a daily dose of exercise
Immune-boosting secret A few spin classes or some simple exercises on a stability ball can make a world of difference. Researchers believe that women who work out regularly cut their risk of catching a cold in half compared to their sluggish counterparts. Keeping up the exercise every day for nine months will give you the best results. How to get it Aim for 30 to 45 minutes of moderate activity, such as brisk walking, every day. But don't overdo it: Studies show that wearing yourself out on the Stairmaster can actually lower your immunity.

Get real
Immune-boosting secret Don't be Debbie Downer; but the Pollyanna routine doesn't work either. In a recent study of law students, those with a more optimistic outlook on life had better immunity than their more pessimistic peers, except when they had unrealistic expectations. Too much optimism may lead to unreachable goals, which causes extra stress and lower immunity. How to get it Hope for the best, but don't hinge your entire mental health on landing that big account or your husband remembering that it's his morning to wake up with the kids.

Sneak in soy
Immune-boosting secret The plant-derived antioxidants found in soy mimic the positive effects of estrogen, preventing bone loss and plaque build-up in the arteries. A recent study found that isoflavones also boost the population of B cells, the immune-system marvels that produce antibodies. How to get it Aim for one serving of soy – such as one cup (250 mL) of soy milk, 1/4 cup (50 mL) of roasted soy nuts or 1/2 cup (125 mL) of tofu – per day.

Hit your happy weight
Immune-boosting secret Yo-yo dieting can prevent killer T-cells from defending the body against invading bacteria or viruses, but being obese can also reduce the body's ability to fight disease, says Vancouver-based dietitian Heather McColl. How to get it Hint: It's not the the waist size from that high-school pair of Jordache jeans that determines your ideal weight. Instead, calculate your waist-to-hip ratio. Measure your waist at its smallest point and your hips at their widest, then divide; 0.8 or less is considered ideal. Don't forget: It's OK for your weight to fluctuate by five pounds in either direction.

Keep your friends close
Immune-boosting secret Isolated people tend to have weakened immune systems, possibly due to higher stress levels. This leads to lower invader-fighting T-cell counts. A new study found that more reclusive university freshmen had a poorer antibody response to a flu vaccine than their social counterparts. Two other recent studies found that feelings of loneliness can increase the risk of disease in adults and seniors. How to get it Hey, ladies: A regular night out with your pals is always healthy. Just lay off the martinis and the Jagermeister shots. Three or more drinks can suppress your immune system and leave you with a whopping hangover.

See a doctor
Immune-boosting secret All colds are not created equal, so at some point, you should stop fighting off a persistent cold or flu on your own. Too much self-doctoring can weaken your immune system, says Toronto-based family physician Shafiq Quadri. "Sometimes you need formal bedrest, antibiotics or some other form of medical intervention." How to get it If your symptoms don't seem to be letting up after about three days, schedule an appointment or visit a walk-in clinic. Doctor's orders.

Wash your hands
Immune-boosting secret Regular hand-washing remains the number one way to reduce your odds of catching a cold or the flu. Recent stats find that infected folks spread viruses to 35 per cent of the surfaces they touch. What's more, you can pick up the virus from an infected surface up to 18 hours after contamination. How to get it It's really boring, but running your soapy hands under warm water for at least 15 seconds while scrubbing them to get rid of germs is the way to go. (And it's easier than spending three days in bed.) Keep a bottle of hand sanitizer at your desk and in your purse in case you can't get to a sink.