The saboteur: A weakened immune system
Working long hours pre-vacation can destroy your sleep, and a study from Mount Sinai School of Medicine found that poor sleep before a stressful event reduces immune-system function.
Save your vacation: Starting a week before you leave, drink about 20 ounces of black tea daily. A study published in Proceedings of the National Academy of Sciences revealed that this causes the body to secrete two to four times more interferon, a key element of your body’s infection-protection arsenal.
2. Hit the Pharmacy
The saboteur: Acute mountain sickness
At 8,000-plus feet in elevation, reduced air pressure and lower oxygen levels can induce headaches, nausea, dizziness, and in severe cases, pulmonary edema (fluid in the lungs).
Save your vacation: Before you leave, ask your doc for acetazolamide, a drug that helps your body metabolize more oxygen. In a study, people who took 250 milligrams twice a day after traveling from sea level to 12,000 feet relieved all symptoms. Take it a day or two before departure and continue until 48 hours after you arrive.
3. Sip Water During a Flight
The saboteur: GI trouble
Time-zone changes and poor eating can alter your normally clocklike bowel movements. “We often leave our healthy diets behind, which stresses our digestion,” says Mark Wise, M.D., author of The Travel Doctor.
Save your vacation: Hydration is the key. Limit alcohol, caffeine, and other diuretics, and be sure to drink 64 to 80 ounces of water a day during your trip. You can help combat diarrhea, gas, and bloating with a probiotic that fights harmful bacteria. Try BioBeads by Natrol. ($15 for 30 beads, natrol.com)
4. Eat Preflight Protein
The saboteur: Nausea
If your body’s motion detectors sense movement differently (e.g., your view of the cabin stays the same but your inner ear senses a drop), motion sickness is likely to ensue, according to the American Academy of Neurology.
Save your vacation: Have a burger. The right preflight meal can soothe your stomach. A Pennsylvania State University study found that subjects felt up to 26 percent less nauseated when they ate a protein-packed meal, compared with a carb-loaded meal or no food at all.
5. Moisturize Mucous Membranes
The saboteur: Arid air
A jet’s cabin air can be as dry as the Sahara—as low as 5 percent humidity, according to aircraft manufacturer Boeing. This can lead to excessive nasal dryness, which can trigger tearing of mucous membranes and facilitate infection. (If you experience frequent nosebleeds, you may be especially sensitive to dry air.)
Save your vacation: For your nostrils, pack an over-the-counter saline gel, like Ayr. To keep your skin hydrated, drink 20 ounces of water while you’re in flight, says travel-medicine specialist Terri Rock, M.D. Make sure it’s bottled, and buy it after you pass security.
6. Pack Your Own Purifier
The saboteur: Bad water
The United Nations estimates that 36 percent of drinking water in Africa doesn’t meet quality standards. (It’s 22 percent in Asia and 18 percent in Latin America and the Caribbean.) And the EPA found that 15 percent of water samples taken from 327 planes probably contained harmful pathogens.
Save your vacation: Skip the in-flight coffee and tea, which may be made with water from the jet’s tanks, and don’t brush your teeth in the lavatories. Bring your own water filter on your trip. We like the Katadyn Exstream personal water bottle purifier. ($50, katadyn.us)