Coffee After Noon? How Does It Affect Our Bodies?

Have you ever found yourself staring into space in the afternoon and thought, "I could really use a coffee"? We rely on coffee to help us wake up in the mornings, so it makes sense that we turn to it at other times of the day when we're feeling tired. Let's discuss what happens when you drink coffee late in the day and whether it's a good idea. We'll also look at the ideal times to drink coffee so that you can enjoy more pep in your step without disrupting your body's natural rhythm.

First, let's talk about what coffee contains that makes it the super drink so many people around the world love. You may already know that coffee beans are seeds from coffee cherries. As in the case of other plants, coffee has a complex makeup that allows it to grow and thrive in certain areas, present a distinct taste and have unique effects on our bodies.

Roasting coffee causes a series of chemical reactions to occur, so the roasted coffee you drink won't be quite the same as if you consumed the raw plant. Still, the roasted coffee we enjoy contains more than 1,000 different chemical compounds, and scientists are still learning about all these compounds and how they affect our bodies. For example, some studies suggest that the antioxidants in coffee, such as chlorogenic acid, may decrease a person's chance of developing diabetes, heart disease and certain cancers.

While new studies periodically come out and reveal or confirm a potential health benefit from the various compounds found in coffee, most people drink it because of one active ingredient in particular. This compound is known as 1,3,7-trimethylxanthine or 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione. A simpler name for it is trimethylxanthine. If you're thinking no compound in coffee could be more important than caffeine, you're right. All of these technical names refer to what we commonly call caffeine.

Caffeine naturally occurs in coffee plants as well as in some other plants, such as tea leaves and cocoa beans. It acts like a natural pesticide, keeping away insects and contaminating the soil to keep other plants from growing around the coffee plant. It helps coffee achieve its reputation for being a hearty plant. Of course, it also helps coffee achieve its reputation for waking us up when we're feeling sluggish.

You may rely on coffee to help you feel energized from time to time, but have you ever wondered how caffeine actually makes you feel more alert? We're going to get a little technical for a minute here and talk about the way caffeine interacts with receptors in your brain. When caffeine enters your body, it splits into three different molecules: theobromine, paraxanthine and theophylline. These molecules all look very similar.

Now, we have to introduce another key player involved in the way caffeine makes you feel energized. This key player is called adenosine. Adenosine is the chemical responsible for relaxing you and making you feel tired. Over the course of a day, adenosine builds up in your brain, which makes you want to go to sleep at the end of the day. Caffeine molecules look similar to adenosine molecules — similar enough, in fact, that they can bind to adenosine receptors.

When caffeine molecules bind to adenosine protein receptors, they keep adenosine molecules from binding with the receptors. The effect is that less adenosine is allowed to build up in your brain, so you can feel more awake than you otherwise would. It's worth noting that people who drink a lot of caffeine build up a dependence because their brains catch on and start producing more adenosine receptors to allow the adenosine to bind in spite of the caffeine molecules getting in the way.

Caffeine doesn't stop at just blocking adenosine from making you sleepy. It also causes increased brain activity. Each type of caffeine molecule contributes in a specific way to give you that energized feeling:

• Theobromine: Encourages increased oxygen and nutrient flow to your brain.
• Paraxanthine: Helps your muscles by breaking down fat at a faster rate.
• Theophylline: Promotes better concentration and increases heart rate.

All of these effects play into giving you that "buzz" that helps you start your workday off right or power through a sluggish afternoon. You won't feel the effects immediately since it takes some time for caffeine to go to work in your body. For most people, it takes about 45 minutes for caffeine to fully kick in.

Now that you understand what caffeine is and how it fights against your body's attempt to make you tired, you may be wondering how drinking it affects your sleep cycle. To understand the answer, let's take a minute to talk about how your body's sleep cycle works.

Your body functions according to a circadian rhythm, or a biological cycle that starts over roughly every 24 hours. A simple way of understanding this rhythm is by thinking of it as your body's internal clock. One of the things the circadian rhythm dictates is your sleep/wake cycle. Part of your hypothalamus in your brain controls your sleep/wake cycle internally, but it's also influenced by outside factors, such as light.

So what does this rhythm look like throughout the day? It partially depends on the person. Each person is different, and you can retrain your sleep cycle to match your lifestyle, as people who work third shift have to do. That said, most people operate on the same general cycles of alertness and tiredness:

• Morning: When you first wake up, you should experience a surge of cortisol. Cortisol is often referred to as the stress hormone, but its primary function is to make you alert.
• Midday: Over the course of your morning and into the afternoon, you're likely to feel your energy levels drop. Think about a typical day. When do you tend to feel the most tired? For most people, this time is somewhere between 1 and 3 p.m.
• Night: When the sun sets and it becomes dark, your eyes let the hypothalamus know that it should start making you feel sleepier. The brain responds by releasing melatonin into your body. Besides that drop in energy you experience in the afternoon, the other significant drop in energy should come in the middle of the night, when most people are sleeping. While you sleep, your body processes the adenosine that built up throughout the day, and then the cycle starts over the next morning.

If you're under-rested, you'll feel the rises and falls of your circadian rhythm more dramatically than you do when you're healthy and well-rested.

Now that you understand how your body's sleep cycle works, let's talk about how coffee can affect it. As we discussed earlier, caffeine interferes with your body's attempt to get sleepy and instead enhances alertness. This process can be helpful when you're feeling tired due to a dip in cortisol, such as right after lunch. It can also be helpful when you're feeling groggy in the morning due to remaining adenosine that didn't get flushed out of your body while you were asleep.

While coffee can help you compensate for those drowsy times when you really need to feel more awake, at the wrong time, the beverage can do more harm than good. Drinking caffeine late in the day, when your cortisol levels should be dropping and adenosine should be building up, can throw off your body's natural rhythm. You know what we mean if you've ever been kept awake because of that cappuccino you ordered with dessert on a night out.

Occasionally relying on caffeine to help you stay awake late to study for an important exam or work the odd late shift isn't really a problem since your body should quickly return to its natural rhythm afterward. However, drinking too much caffeine throughout the day on a regular basis can have more lasting effects on your sleep cycle, leaving you under-rested and overly dependent on caffeine.

With a working understanding of your body's natural sleep/wake cycle and how caffeine affects it, we can address the question of whether you should have coffee late in the day. Most people tend to associate coffee with their morning rituals, but you may also crave a cup when you're feeling that afternoon slump. Is there anything wrong with drinking coffee during this time?

It's difficult to give an accurate answer across the board since everyone's biological rhythms are different. However, most medical experts agree that it's best to cut off your coffee intake around 2 or 3 p.m. That means having coffee in the late morning or right after lunch shouldn't be a problem, but once you're well into the afternoon, you should think twice before you turn to caffeine for a pick-me-up.

You probably already assume that coffee before bed is a bad idea, but in the afternoon, bedtime likely seems like a long way away, so you may feel like there's no way a cup now could keep you up later. It can, unfortunately, because caffeine tends to stay in a person's system for a long time. For most people, it has a half-life of about five hours. In other words, if you have a cup of coffee that contains 100 mg (a pretty average amount) at 4 p.m. at 9 p.m., when your day is winding down, you'll still have 50 mg of caffeine in your bloodstream.

One study found that caffeine affected people's sleep for up to six hours after they consumed it. You may want to count back six hours from your bedtime and make that your personal caffeine cutoff time. Since our bodies are all different, caffeine may remain in your bloodstream for longer or flush out more quickly than average. You may find that a cup of coffee later in the day doesn't have any effect on your sleep that night. You could also realize that you need to stop drinking coffee even earlier in the day.

The most important thing is to know your own body and to do your best to assist its rhythm of wakefulness and sleepiness without throwing it off and causing yourself to feel more tired in the long run rather than more awake. If you want to set yourself up for a restful night's sleep, you should enjoy your coffee during earlier parts of the day.

Now that you know caffeine affects you differently at different times, you're probably wondering when the best times to drink it are. It turns out that this question is currently a fascinating area of study. Even the U.S. military has done research on the topic. They developed an algorithm to determine a person's ideal times to consume caffeine in order to help them stay alert. Following the algorithm's recommendations helped the test subjects perform better with less caffeine.

When you consider the fact that so many people all over the world turn to caffeine to help them perform well at school, at work, at the gym or wherever they find themselves, it makes sense that we should pay closer attention to how we're consuming it.

If you're going to drink coffee — or some other form of caffeine — for a boost of energy, you want to make sure you get the most out of it. Timing your coffee breaks strategically can help you maximize the benefits from caffeine in a way that also won't mess with your body's natural rhythms. So when are the most strategic times to pour that fresh cup of coffee?

If you were looking at a chart of your body's cortisol spikes throughout the day, the best times to drink coffee would be in between those spikes, when that cortisol is low. You should feel more tired during these times. When your body's cortisol levels are up, it's not a good idea to drink coffee since your body will interpret the caffeine as a replacement for cortisol. This issue will cause you to build up a tolerance for caffeine, rendering it ineffective.

When are these peak cortisol times? Generally, your body's cortisol levels will be at their highest from:

• 8 to 9 a.m.
• 12 to 1 p.m.
• 5:30 to 6:30 p.m.

That means the best time to drink coffee is at any time from about 9:30 to 11:30 a.m. If you want coffee again later in the day, the magic time to fit it in is around 1:30 p.m. That way, you can time it after your lunchtime cortisol spike and before it's late enough that it will affect your sleep later.

You may be surprised by these times if you're used to drinking coffee when you first get up. Many of us feel like we need coffee to start the day because we feel groggy, but the truth is that you woke up partly because your alarm clock went off and partly because your circadian rhythm knew it was time for a boost of cortisol. Your body is already working on waking you up in the morning, so you're jumping the gun if you guzzle a cup of joe as soon as you wake up.

If you want to get the most out of your morning cup of coffee, wait a while after getting up before you drink it. The best time, as we just saw, would be around 9:30 or later. For many of us, that means we have to get through our morning routine and show up at work before we ever taste that first drop of good morning goodness. It may seem like a long time to wait if you get up early, but you should notice that it helps your body maintain a more consistent level of energy throughout your morning.

While we're talking about when to drink coffee, we should also focus for a moment on the question of how much coffee a person should drink. If you drink too much, it could mess up your body's natural cycle, no matter when you drink it. According to the Mayo Clinic, a typical healthy adult can have as much as 400 mg of caffeine in a day without any problems. It would take about four cups of coffee to reach that amount of caffeine.

Since some people are more sensitive to caffeine than others, it's critical for you to be attuned to how your body responds to caffeine. You should decrease your caffeine consumption if you notice that you're experiencing any of the following symptoms:

• Rapid heart rate
• Anxiety or stress
• Irritability
• Muscle tremors
• Migraine headaches
• Overactive bladder
• Upset stomach
• Trouble sleeping

The key takeaway is that caffeine is a drug. As with any other drug, you can abuse it by consuming too much. However, unlike many other drugs, you don't have to worry about caffeine becoming lethal. It would take approximately 10 grams for that to happen — far more than you could get through coffee, even if you drank it until you couldn't fit any more in your stomach.

If you're craving the taste of coffee later in the day or after you've already reached your max of caffeine for the day, the perfect solution is to brew a cup of quality decaf. That way, you can still enjoy the warmth and deliciousness of great coffee without the jitters or sleep interference.

It's worth noting that caffeine isn't the only thing to worry about when you're drinking too much coffee. If you prefer your coffee with add-ins like milk and sugar, you should also pay attention to how many fat, calories and grams of sugar you're taking in with each cup. If you love to dress your coffee up, the good news is that there are healthy ways to enjoy extra flavors. If you like your coffee black, there are no worries on this front. Coffee alone has virtually no calories and no fat or sugar.

Timing your coffee breaks shouldn't take the joy out of drinking your favorite beverage. Instead, it should make the experience something to look forward to each day and help the caffeine have the most positive possible effect on your body. You'll especially look forward to that mid-morning cup of coffee when you know it's made from quality coffee beans that are roasted to perfection.

For the most enjoyable coffee experience, get your coffee from Barnie's Coffee & Tea. At Barnie's, we believe drinking coffee should be far more than a merely practical attempt to get through the day. A truly delicious cup of coffee can be a bright spot in your routine that elevates your mood and helps you take on the rest of the day with the energy and confidence you need to succeed.

At night, you can curl up with a cup of our decaffeinated tea or coffee for some relaxation and then enjoy a restful night's sleep. No matter the time of day, Barnie's has the perfect drinks to help you enjoy it. Find a bean, blend or flavor that piques your interest and start turning your coffee ritual into a highlight of your day.