You’ve settled into your seat, buckled up, and the beverage cart is rolling your way. That friendly flight attendant is ready to hand you just about anything you’d like to sip on. Sounds harmless, right? Well, here’s the thing. Not every drink option at cruising altitude is as innocent as it seems. After years of observing passengers and experiencing flights firsthand, seasoned crew members have learned which beverages can turn your travel experience from pleasant to downright uncomfortable. Let’s be real, what you choose to drink up there can affect everything from your hydration levels to your stomach comfort, and even how well you sleep once you land. So buckle in, because what comes next might just change how you order on your next flight.
Hot Coffee and Tea From the Onboard Tanks
Flight attendants warn against drinking hot beverages such as tea and coffee because the water heaters are rarely cleaned unless they are broken. The water used to brew your morning cup doesn’t come from pristine bottled sources. Instead, it’s pulled from onboard tanks that have raised serious concerns among industry insiders. A study by the Center for Food as Medicine & Longevity examined over 35,000 water samples from airlines over three years and found potentially unhealthy water, recommending travelers stick to bottled water and avoid coffee or tea served on aircraft. An Environmental Protection Agency survey in 2013 indicated the drinking water in most commercial flights tested positive for bacteria, and a 2004 investigation revealed water in most planes contained high percentages of coliform, a bacteria found in feces. Honestly, it’s hard to ignore those findings. Even though the water is heated to high temperatures, which can kill some bacteria, many flight attendants themselves avoid these drinks entirely, opting instead for sealed beverages.
Alcoholic Beverages
If you think a glass of wine or a cocktail will help you relax during your flight, you might want to reconsider. Research published in the journal Thorax discovered that when people fall asleep after consuming alcohol at low air pressures experienced during flights, blood oxygen drops to worrisome levels and heart rates increase even in healthy young individuals. The cabin pressure at cruising altitude already reduces oxygen levels in your blood, and adding alcohol to the mix compounds the problem significantly. People who drank before sleeping in an altitude chamber had blood oxygen saturation drop to 85% with heart rates rising to nearly 88 beats per minute, compared to 95% oxygen saturation and 77 beats per minute at sea level. According to the International Air Transport Association, alcohol factors into 27% of reported disruptive passenger incidents. Alcohol also dehydrates you faster in the already dry cabin air, which can worsen jet lag and leave you feeling worse when you land. Water is truly your friend up there.
Carbonated Sodas and Sparkling Water
That fizzy soda might seem refreshing when you’re parched, yet it’s one of the worst choices you can make at altitude. Air pressure decreases at higher altitudes, and basic physics dictate that gases expand as air pressure decreases, meaning gas in your gut puts more pressure against bowel walls as altitudes rise. The bubbles in carbonated drinks are carbon dioxide gas that may expand in the digestive tract during flight, causing more discomfort and distension than usual. The altitude itself already makes you prone to bloating, a phenomenon that even has its own name. High-altitude bloating is called HAFE, which stands for high altitude flatus expulsion. Adding carbonation just makes everything worse, leaving you uncomfortable and gassy for the rest of your journey.
Excessive Caffeinated Drinks
A small cup of coffee might not hurt, but loading up on multiple caffeinated beverages is a mistake many travelers make. Drinks like coffee combined with lower air pressure can increase urination, and avoiding alcohol and caffeine can prevent further dehydration during flights. Caffeine is a diuretic, meaning it makes you lose more water through increased urination at a time when your body is already struggling with the dry cabin air. Cabin humidity can drop as low as 10 to 20 percent, a level drier than most deserts on Earth. Excessive caffeine intake can also trigger headaches, disrupt your sleep patterns, and make jet lag significantly worse once you reach your destination. Honestly, I know it sounds crazy, but limiting your caffeine and choosing water instead will make you feel so much better when you finally step off that plane.
Diet Sodas With Artificial Sweeteners
Diet sodas might seem like a smarter choice than regular sugary versions, yet they come with their own set of problems at altitude. These beverages contain artificial sweeteners like sorbitol and other sugar alcohols that can cause digestive distress even on the ground. At altitude, where your digestive system is already under stress from cabin pressure changes, these sweeteners can make bloating and gas even worse. The altitude makes carbonated drinks foam more, particularly Diet Coke, which means more bubbles to make your belly puff. Many passengers report that diet drinks leave them feeling uncomfortably bloated and gassy throughout their flight. The combination of carbonation, artificial sweeteners, and reduced cabin pressure creates a perfect storm for digestive discomfort that can last well beyond your flight time.
Drinks Made With Airplane Tap Water, Including Ice
This one might surprise you, but any beverage made with airplane tap water should raise a red flag. That includes not just coffee and tea, but also ice cubes in your drinks. Researchers advise passengers to never drink water aboard an airplane unless it’s sealed in a bottle, including coffee or tea, and to avoid washing hands in bathrooms, using hand sanitizer instead. Testing found the presence of microorganisms in the water, including total coliform bacteria, whose presence indicates that disease-causing pathogens could be there as well. Among major U.S. airlines, American Airlines, JetBlue, and Spirit earned a D rating for water quality, while Delta and Frontier were top-ranked with A grades. Flight attendants know this better than anyone, which is why many refuse to drink anything that isn’t bottled or canned. When that beverage cart comes around, asking for your drink without ice might be the smartest move you make all flight.
Your body goes through enough stress during air travel without adding beverages that make things worse. Cabin pressure, dehydration, and altitude changes already put strain on your system. Choosing the right drinks can mean the difference between arriving at your destination feeling decent versus feeling absolutely drained. Stick to sealed bottled water, avoid anything made with tap water, and skip the fizzy and alcoholic options. Your body will thank you when you land feeling refreshed instead of bloated and exhausted. What do you think? Will you change your drink order next time you fly?
