Drinking at 30,000 Feet: What Every Flyer Should Know

There is something uniquely appealing about having a drink after you’ve settled into your seat for your flight. Perhaps it’s having a glass of wine for those flight jitters, a celebratory cocktail to kick off your vacation, or a beer to enjoy  watching a sports game or movie on the flight.

However, there are serious considerations with drinking alcohol at altitude.

Why Alcohol Hits Different in the Sky

We’ll start with what’s actually happening inside your cabin while flying.

Pressurization

• Commercial flights typically cruise between 30,000 and 42,000 feet.  35,000 to 40,000 feet is the most common cruise altitude.¹
• At these altitudes the air is thinner, reducing drag and improving the plane’s efficiency.
• Colder temperature also improves engine performance. Air cools at 2°C per 1,000 feet so at 35,000 feet, the air is 70°C colder.
• At sea level (0 feet), the oxygen content of each breath of air is 20.9%. At 35,000 feet, the oxygen content is 5.5%. You cannot survive that extremely low oxygen level.²
• Even above 8,000 feet, your body struggles with the reduced oxygen levels, which can lead to hypoxia.³
• Thus aircraft cabins are pressurized to simulate a 6,000 to 8,000 foot cabin at altitude.
• At 6,000 feet, the oxygen content is 16.6%. This is the same altitude as Colorado Springs.²
• Colorado Springs is also where the U.S. Olympic Training Center is located, due to its high altitude.

Humidity

• Aircraft draw in that cold air at altitude (-70°C), which is also extremely dry.
• Aircraft do not have humidification equipment.  That would add weight and create a risk of corrosion and ice formation.⁴
• Consequently, aircraft cabins usually maintain humidity levels between 10% and 20%.⁵
• For long-haul flights, those humidity levels can drop to 5% – 10%.⁵
• Normal comfortable indoor humidity levels are between 30% – 50%.⁵
• Desert humidity levels are between 20% – 30%, with the Sahara Desert between 10% – 25%.⁵

So when you board your plane at Heathrow airport in London at 36 feet and 70% humidity, at cruise altitude you are living life at 6,000 feet with Sahara Desert humidity for several hours.

Physiology

• Your liver processes alcohol at approximately the same rate whether you’re on the ground or in the air.⁶
• However, the high-altitude lower oxygen levels combined with the desert dry cabin air create an environment that amplifies alcohol’s effects.⁶
• Low humidity can dehydrate you. On a 10-hour flight, you can lose up to 2 liters of water.⁵ 
• Since alcohol is a diuretic (makes you pee), it only makes dehydration worse.
• As a result, the glass of wine, cocktail or can of beer may feel more like two, making you likely to feel the effects faster.

The Upsides of In-Flight Drinking

Relaxation and Anxiety Relief

• A drink can help take the edge off for nervous flyers.
• The ritual of ordering something familiar, feeling the slight buzz, and the distraction can all contribute to a more comfortable flight experience.

Social Lubrication

• Chatting with your neighbor or travel companion over a drink can make long flights feel less boring.
• Sometimes it may lead to interesting conversations.

Marking the Occasion

• There’s just something special about that first drink when your vacation officially begins.
• It’s a psychological marker that you’ve left work behind and entered holiday mode.

The Downsides Worth Considering

Amplified Dehydration

• This is the biggest one.
• Alcohol compounds the dehydrating effect of the extremely dry cabin air.
• This dehydration double-whammy can result in worse hangovers and that awful “airplane feeling” when you land.

Disrupted Sleep Quality

• While alcohol may help you fall asleep initially, it significantly disrupts your sleep cycles.⁷
• You’ll likely wake up more frequently and get less restorative deep sleep.⁷
• This is especially problematic on overnight flights to a new time zone.

Increased Risk of Deep Vein Thrombosis (DVT)

• Alcohol can contribute to dehydration and reduced mobility, both risk factors for blood clots on long flights.⁸
• This is especially important to consider on flights longer than four hours.

Unpredictable Effects

• Since alcohol affects you more strongly at altitude, you may become more intoxicated than intended.
• This can lead to poor decision-making, embarrassing behavior, or becoming that passenger nobody wants to sit near.
• It can even lead to your arrest if you become out of control.

Jet Lag Amplification

• Alcohol interferes with your body’s ability to adjust to new time zones by disrupting your circadian rhythms and sleep patterns, potentially adding days to your jet lag recovery.⁹

Flying Smart

Your Goal is to Enjoy Your Flight

• If you choose to drink during your flight, moderation is key.
• For every drink you have, have at least a glass of water as well. Stay hydrated.
• Stick to 1 – 2 drinks during your flight. If you have a long flight (over 4 hours), stay hydrated with water.
• Avoid drinking alcohol within a few hours landing. Especially important if you have a meeting or event when you land.
• Skip having a drink on shorter flights where dehydration is much less.
• You may actually discover that having a sparkling water or juice is better than you’d expect.
• The goal is to enjoy your flight and arrive at your destination feeling good and ready to enjoy your trip.

Buddy and I

• On short hops (under 2 hours) we will only have Ginger Ale or water.
• On international flights, we normally enjoy a glass of champagne to celebrate the start of our journey. However, we always have a bottle of water to go along with it.
• At cruising altitude, our first beverage is always Ginger Ale, or lemon-lime soda, and a glass/cup with no ice.
• If there is no meal on the flight, we enjoy a glass or two of white wine, depending on the flight time.
• If there is no meal on the flight, we will also take advantage of the free snacks offered. We loathe drinking on an empty stomach.
• If there is a meal on the flight, our wine choice depends on the meat served. White with chicken/pork/seafood. Red with beef/red meat.
• Again, for each glass of alcohol we have, we drink a glass of Ginger Ale or water.
• An hour before landing, we will only have Ginger Ale or water.
• We love flying and want to enjoy the flight.

   

Here’s to safe travels and making smart choices in the sky!

Buddy and Jordan

References

1. www.faa.gov
2. www.higherpeak.com
3. www.aviationinfo.net
4. www.ncbi.nlm.nih.gov
5. www.travelgrom.com
6. asma.org
7. www.mdanderson.org
8. www.cdc.gov
9. www.thelancet.com