“Right when your adrenaline hits, it increases the release of sugar stores from your liver, and then you crash,” Akkerman says. “And if you haven’t eaten anything, you can get hypoglycemic, which can make you worry about everything else.”
The solution, says Akkerman, is to have less complex carbohydrates and protein. This can be anything from granola to peanut butter toast. The extra energy from food will keep your body from going out mid-morning.
This, I learned from Akkerman, is the root of my six o’clock morning jitters. It wasn’t caffeine. It was adrenaline and hypoglycemia. I’m not a breakfast person, but on Akkerman’s advice, I now eat a handful of nuts every morning before my morning brew, to avoid an unexpected sugar crash.
Average Your Caffeine Level
Some people process caffeine quickly and efficiently. Some people don’t. Some people are also older than others. But the general rule of thumb from US Food and Drug Administration is that 400 milligrams of caffeine per day is the highest dose that has been proven safe for most people.
This could be four 8-ounce mugs of drip coffee or three shots of espresso. If you are pregnant, a safe dose may be half this amount.
But people can also vary greatly in their ability to process caffeine. “There’s actually a genetic test you can take — it’s the CYP1A2 gene — that can tell you if you’re a slow or fast metabolizer of caffeine,” says Zumpano. But for the most part, he says, the key lies in listening to your body. If you are experiencing rapid heartbeat or palpitations, you may have had too much caffeine.
The same is true, he says, if you feel the odd combination of “wired but also tired” in the afternoon—a common feeling that’s often the result of high levels of adrenaline or cortisol triggered along with a post-lunch sugar crash.
“I’m a heart nutritionist,” Zumpano says. “So I see a lot of people with arrhythmia, tachycardia, A-fib—all of those things are exacerbated by caffeine. Caffeine is the first thing I get people off of, and it controls their heart rate.”
Stop Drinking Coffee By Afternoon
I know, I know. It is polite in France to have a small cup of coffee after dinner.
But Europeans also have a different circadian rhythm than Americans, Zumpano notes, and daytime rest. They also don’t drink their coffee out of a 10 ounce cup.
As a rule of thumb, say Akkerman and Zumpano, most people should stop drinking coffee by 3 p.m., or maybe even noon. This will depend on how much coffee you drink each day and how fast your body processes caffeine. Although most people can still fall asleep after consuming caffeine late in the day, Zumpano says, it often still has an impact on your sleep quality. Cortisol leaves your body only slowly.
“I have patients who are like, ‘I can drink caffeine anytime, and it doesn’t affect my sleep,’ Zumpano says. “And I say, ‘Why don’t we just try to get rid of it?’ And they’re like, ‘Oh my God, I’m sleeping better. I sleep all night. I didn’t know that was possible.’”
Don’t Turn It Into Afternoon Tea
Akkerman, a neurologist, also cautions against switching to tea in the afternoon—a habit that’s common among those who don’t want caffeine spikes during the day.
Tea generally has less caffeine than coffee. On average, a cup of tea contains half to three-quarters of the amount of caffeine in a drip mug. But the reason for the mild appearance is not the lack of caffeine. Instead, tea releases caffeine more slowly. The phenols in tea slow down the rate at which your body processes caffeine, resulting in a high and buzzy feeling.
