Causes of Sleepiness
In a AAA study on drowsy drivers, about 50% of the sleepy drivers who crashed reported that they felt only “slightly” or “not at all” drowsy before they crashed. That percent isn’t far off the 40% who said they would deal with any drowsiness while driving after they got sleepy rather than try to prevent it.
We’ll skip past the obvious flaw in that “logic” – it’s pretty clear if you’re waiting to prevent sleepiness until after you’re sleepy, but don’t know you’re sleepy until after you crash, it’s probably a little late to do anything about it.
The less obvious problem in that logic is how caffeine actually works to keep you awake and alert. Caffeine works much better as a prophylactic, preventative measure to keep you from geting tired than an after-the-fact remedy. Here’s how it works: The more tired you are, the more of a nucleoside, adenosine, your body creates. When adenosine finds its way to the adenosine receptors in your brain, *poof*, those receptors signal your body it’s time to rest, i.e. you get tired. One of the key ways caffeine works is by functioning as an adenosine blocker. Caffeine is structurally similar to adenosine so it kinda sorta fits, but different enough not to switch on the sleep response. If there’s a caffeine molecule lodged in there first, the adenosine molecule can’t get in to bid and make you tired.
What to do if you’re already tired?
If the adenosine gets in there first, then then the best thing you can do is fill your body with caffeine and then take a short nap of even 15-20 minutes. This will signal your body to “refresh” and now the caffeine can fill your adenosine receptors first!
Sleepiness or drowsiness is usually brought one of two factors: lack of sleep (or the lack of good sleep), and your body’s natural body clock which programs us to be sleepy twice a day, once in the middle of our night time sleep period, and a second time in the late afternoon. According to “Principles and Practice of Sleep Medicine,” other factors such as what you eat, room temperature, monotony (boring meeting, long, straight highway), etc. can “unmask” the physiological need but do not cause it. We prefer our sleepiness masked. Stay away from these foods before a road trip because they can exacerbate sleepiness:
Don’t make it Worse!
Good foods that are good to avoid before a long road trip:
Almonds: Almonds contain tryptophan and magnesium, which both help to naturally reduce muscle and nerve function while also steadying your heart rhythm, so great for a pre-bedtime snack, but not so helpful pre-roadtrip.
Honey: Honey contains glucose, which triggers your brain to stopproducing orexin — one of the chemicals known to trigger alertness. We like alertness when we’re driving. So we like orexin. And we’d prefer all the other drivers had some too. Save your inner Pooh for until after you arrive.
Bananas: The magnesium and potassium found in bananas serve as muscle and nerve relaxants. Accordingly, bananas make an awesomely health spa treat, but are clearly
less useful in the drivers’ seat. What’s more, the Vitamin B6 found in the fruit also converts tryptophan into serotonin, increasing relaxation even more. Vitamin B6 has other benefits, which is why it’s in some energy drinks, but if alertness right now is one of your goals, avoid bananas and vitamin B6.
Cereal with milk – If you’re planning on eating a healthy breakfast before a roadtrip, try something other than cereal and milk. Ironically, cereal and milk make a great bedtime food. Cereal has a great balance of protein and carbohydrates. These two essential nutrients, when combined, will put you to sleep in no time. That’s because protein contains an amino acid called tryptophan, which makes you feel sleepy, and carbohydrates help tryptophan reach the brain more easily. Not really a big problem if you’ve had a good night sleep, but possibly an issue if you, like us, had to put sleep on the back burner.
High Glycemic Foods – Foods with a high glycemic index spike your body’s blood sugar, which in turn causes your body to start manufacturing insulin on an over-time, 3-shifts-a-day schedule. That’s a) not really healthy and b) a good way to fall asleep right after the initial sugar rush. And since sleeping is a really bad idea while driving, definitely stay away from those high glycemic index foods. And since those foods aren’t always obvious (e.g. a baked potato can have twice the glycemic index of a cola!) we’d suggest reviewing a good glycemic index chart so you know what you’re eating and drinking.
Continued tomorrow with Part III tomorrow: What you should eat and drink, and how to stay awake