When is the Best Time to Drink Coffee? See the Science
For millions of people, their “morning routine” is some variation of the following: roll out of bed, pour coffee, drink coffee until the brain begins to function, start day. You may even have a general rule that you don’t speak to anyone — and more importantly, no one should speak to you — until after your first cup of coffee. This “routine” may be even more critical if you stayed up late or didn’t sleep all that well the night before. If that sounds like you, new research suggests you may want to rethink your morning routine and the best time to drink coffee.
Health Benefits of Coffee
Of course, chances are good that the reason this is such a common morning routine is because of caffeine’s well-known ability to perk you up and get you going. What’s more, there are loads of benefits associated with regular coffee consumption. For example, regular coffee consumption has been linked to a decreased risk of:
- Cardiovascular disease
- Type II diabetes
- Parkinson’s disease
- Alzheimer’s disease
- Liver disease
- Diseases of the gut
Coffee consumption has also been shown to help support or improve:
- Skin health
- Immune system function
- Social skills, as well as group participation and engagement
- Asthma control
- Joy and feelings of well-being
According to the 2015 U.S. Dietary Guidelines Advisory Committee Report, moderate consumption of coffee (i.e., around five 5- to 6-ounce cups per day) can be considered part of a healthy diet. That’s a good thing as nearly 50% of us wake up in the morning and pour a cup (at least) o’ joe.
The Problem With Early Morning Coffee
Yet, new research from the British Journal of Nutrition has revealed that when you consume coffee is also vitally important—especially if you’ve had a rough or short night’s sleep. You see, researchers found that after just one difficult night, a cup of coffee consumed first thing in the morning (before breakfast) had a powerfully negative effect on metabolic function, including impaired blood sugar control and insulin sensitivity after carbohydrates were consumed.
Consuming coffee/caffeine before a carb-containing meal—particularly if you haven’t had a great night of sleep—appears to impair carbohydrate metabolism, which can have a cascade of effects on mood, energy levels, appetite, subsequent food choices, etc., in the short term and perhaps more negative effects over the long haul.
In the randomized crossover design study, 29 young adults participated in 3 separate overnight experiments. One consisted of a “normal” night of sleep, which involved sleeping for around 7 hours with no interruption. On the two other nights, participants were disturbed for around 5 minutes every hour. This type of interrupted sleep is referred to as “fragmented” sleep.
The morning after each of the sleep interventions, the participants were given a sugary drink intended to mimic a typical breakfast in terms of calories. On one of the mornings after a night of “fragmented” sleep, the participants drank a cup of black coffee (with around 300 mg of caffeine) 30 minutes before they consumed the sugary drink. For all the conditions, the researchers took blood samples from each participant after they consumed the sugary drink — an assessment known as an oral glucose tolerance test.
You may think that all of those who had the interrupted sleep would find blood sugar and insulin response altered. After all, a good night’s sleep is essential for many reasons, including blood sugar control, and disrupted sleep has been shown to independently disrupt carbohydrate metabolism. Surprisingly, however, these metabolic markers weren’t negatively affected UNLESS the participants had also consumed coffee before the sugary breakfast drink.
In other words, a single night of tossing and turning didn’t negatively affect insulin sensitivity or glucose tolerance. Yet, caffeinated coffee before breakfast combined with interrupted sleep did. In fact, the very-common combination of morning coffee and disrupted sleep negatively affected carbohydrate metabolism by around 50%—even with just a single night.
The Best Time to Drink Coffee
Researchers, therefore, recommended waiting until after breakfast before drinking coffee, at least after tossing and turning through the night to balance the effects of coffee you want (i.e., a nice wake-up call) with those you don’t (i.e., impaired metabolism).
Alternatively, if you’re a traditional breakfast-eater and you like your morning coffee, a work-around to consider is going with a less-traditional low-carb breakfast, such as eggs and bacon or a veggie-loaded omelet. Coffee seems to shift the body into more of a fat-burning mode as it is, so it seems to make sense to shift the macronutrient profile of your breakfast toward this preference.
While this is only one small experiment, the findings aren’t necessarily groundbreaking when it comes to the best time to drink coffee. That is, previous studies have also found that consumption of caffeinated coffee (or other caffeinated beverages, foods, supplements, etc.) generally has an acute detrimental effect on glycemic control when consumed around the time of a carbohydrate-containing feeding.
Having said that, individual differences may apply. For example, certain genetic predispositions may result in some folks metabolizing caffeine more quickly than others, and that may buffer the potential effect on carbohydrate metabolism. So larger, longer studies are warranted.
More importantly, perhaps, as that this short-term, acute effect does not negate the potential long-term benefits of regular coffee consumption. Keep in mind that coffee is much more than a vehicle for caffeine. In fact, it contains over 600 bioactive compounds (one such example is the chlorogenic acids in coffee), and it is quite possible that some of these may elicit opposite or positive effects on carbohydrate metabolism over the long haul. This may explain why regular coffee (both caffeinated and decaffeinated) consumption has been shown to reduce the risk of type 2 diabetes.
Having said that, for those who do find their nights regularly disrupted, with or without coffee before breakfast, the lack of sleep has been associated with negative effects on the metabolism and more. So, good sleep hygiene remains a top priority.
While there’s still more to learn, the best time to drink coffee may no longer be “as soon as I wake up” and instead become “after I eat breakfast” to experience the positive benefits without negatively affecting carbohydrate metabolism.