We are well in the midst of cold and flu season. Read on for 9 well-researched, scientifically-sound tips to keep you healthy in the months to come.
1. Prioritize sleep.
Aim for 7 to 9 hours every night. Researchers at Carnegie Mellon University had 153 healthy men and women track their sleep duration over a 14-day period. Participants with less than 7 hours of sleep were 2.94 times more likely to get sick than those with 8 or more hours of sleep.
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2. Get plenty of exercise, but be moderate with intensity and duration.
Prolonged, intense exercise can actually weaken the immune system. For those not acclimated to endurance events, starting training for a marathon or other endurance event is not recommended during cold and flu season, as the immune system is put under considerable strain each time distance or duration is increased. Research published in the Journal of Athletic Training reports "diminished neutrophil function in athletes during periods of intense and heavy training… and risk of upper respiratory tract infection is elevated."
Studies also show that moderate, regular exercise has a strong beneficial effect on immune health. Research on exact duration, frequency and intensity is lacking, but activities I recommend are:
- Gentle cardio, like Walking, for 45-60 minutes a day
- More intense cardio like Running, Swimming, Biking, or Elliptical for 30-40 minutes, 3-5 days a week
- High-Intensity Interval Training (HIIT), like Tabata sprints with strength training, 3 days a week
- Gentle to moderate intensity Yoga, Tai Chi, Qi Gong, or Pilates daily, or if it's more vigorous Vinyasa Yoga, Bikram Yoga or Daily Method, limit it to 3-5 times a week.
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3. Wash your hands frequently.
And don't touch your eyes or nose unless you've just washed your hands. Cold and flu viruses are more effectively passed through manual not aerosol transmission, and hand washing is the best way to prevent manual transmission. Both alcohol-based hand sanitizers and soap and water work, but soap and water is the gold standard. Research published in the journal Clinical Infectious Diseases showed that soap and water removed more virus than three alcohol-based hand sanitizers, when hands were rubbed vigorously for 15 or more seconds under warm water.
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4. Reduce stress.
Psychological stress is clearly associated with an increased risk of acute infectious diseases. Many factors in our lives make avoiding stress unrealistic. Still, there are things we can all do to make fun, relaxation, and quality time with family and friends more of a priority in our lives.
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5. Eat plenty of healthy bacteria.
Take a probiotic supplement; or even better, eat high-quality, naturally fermented foods daily. Some of my favorites are yogurt (full-fat, sugar-free), kefir, raw sauerkraut, kimchi, and kombucha. Dr. Maydani, a researcher at Tufts University says, "The gut is the largest immune organ in the body, accounting for 25% of the immune cells in the body that provide 50% of the body’s immune response. There are more than 400 species of bacteria residing in the gut, and they have symbiotic relationships with your body.” It's unclear exactly how these friendly bacteria support our immune system, but a number of studies have shown that use of probiotic supplements decrease frequency of acute respiratory illnesses.
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6. Have your Vitamin D levels checked.
A growing body of evidence now links adequate levels of Vitamin D to a reduction in frequency of acute respiratory infections. I prefer to keep my levels high through moderate exposure to sunlight, eating liver, eggs and full-fat dairy, and by taking a high-quality cod liver oil supplement. If your levels are considerably low however, a Vitamin D supplement is recommended.
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7. Drink green tea.
If you're not sensitive to caffeine, drink lots of green tea during the first half of the day. Polyphenols, like EGCG, found in green tea have an extremely beneficial immune-modulating effect. In addition to green tea's many other health benefits, research shows that it has a specific anti-viral effect on the influenza virus. Make sure to use high-quality loose-leaf tea. A study published by the US Department of Agriculture (USDA) in 2007 analyzed close to 400 foods for their EGCG content. They found that loose leaf, freshly brewed green tea had 180mg of EGCG. Decaffeinated green tea had 60mg, flavored green tea had only 45mg, and bottled green tea had a mere 9mg of EGCG.
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8. Eat your "superfoods".
Add lots of immune-enhancing and inflammation-reducing foods to your meals. Especially useful are maitake and shiitake mushrooms; oregano, basil, parsley and other culinary herbs; garlic, ginger, turmeric, onion, and cayenne pepper; cruciferous vegetables, and berries. Make sure that every meal is loaded with as many of the above foods as possible.
Sources:
Fuhrman J. Super Immunity. HarperCollins, 2011.
9. Reduce your intake of sugar and refined carbohydrates.
I have to admit… I have a sweet tooth! Made especially difficult by the fact that cooking scones, cookies and pumpkin pie is so much fun. I still believe a treat now and then is good for the soul, but all things in moderation. Sugar, most other sweeteners, and refined carbohydrates like flour products and white rice, have a long list of documented, harmful effects on our health. Add to the list immunosuppression, as shown by a number of in vitro studies. Human studies are lacking, but when they're eventually done, I think I can predict the results.
Sources:
Taubes G. Good Calories, Bad Calories. Random House, 2007.
Labels: Cold & Flu Prevention