5 Reasons Coffee Can Make You Sleepy

For those who drink more than four cups of coffee a day, caffeine can act as a diuretic. This means it spreads quickly throughout your body, making you go to the bathroom more often.

Over time, dehydration can affect your heart’s ability to maintain blood pressure and put you at risk for dehydration. If you are still dehydrated, you may experience daytime sleepiness and lethargy. Dehydration can also cause a fast heart rate and low blood pressure, which often causes anxiety. In most cases, drinking coffee in moderation, one to two cups a day, does not cause dehydration. So make sure to monitor your coffee consumption every day.

While caffeinated drinks like coffee, energy drinks, and soda can force us to go to the bathroom more often, the water in coffee can ward off dehydration. However, if you drink a lot of coffee, make sure to drink plenty of water throughout the day. According to the USDA’s water intake recommendations, older men should have about 13 glasses a day and older women should have 9 glasses.

1. Caffeine blocks adenosine
   Adenosine is a chemical produced in the central nervous system that regulates our sleep patterns. Like melatonin, the sleep hormone, adenosine levels increase during the day to keep us awake. At night they took off to help us fall asleep. Adenosine does this by binding to special receptors in the brain that slow activity and induce relaxation. When you drink coffee, caffeine binds to these receptors and prevents them from taking up adenosine.

However, the body still produces adenosine in the morning, even though the receptors don’t take it up. This causes chemicals to build up in the body. Once caffeine is metabolized, high levels of adenosine can lead to extreme fatigue. Because caffeine is absorbed quickly, some people may experience this side effect 45 minutes after consuming it.

2. Coffee is a diuretic
   For those who drink more than four cups of coffee a day, caffeine can act as a diuretic. This means it spreads quickly throughout your body, making you go to the bathroom more often. Over time, dehydration can affect your heart’s ability to maintain blood pressure and put you at risk for dehydration. If you are still dehydrated, you may experience daytime sleepiness and lethargy. Dehydration can also cause a fast heart rate and low blood pressure, which often causes anxiety. In most cases, drinking coffee in moderation, one to two cups a day, does not cause dehydration. So make sure to monitor your coffee consumption every day.

While caffeinated drinks like coffee, energy drinks, and soda can force us to go to the bathroom more often, the water in coffee can ward off dehydration. However, if you drink a lot of coffee, make sure to drink plenty of water throughout the day. According to the USDA’s water intake recommendations, older men should have about 13 glasses a day and older women should have 9 glasses.

3. Coffee sweetener affects blood sugar levels
   Most coffee creams are high in sugar. Additionally, specialty coffees at your local coffee shop may include whipped cream, flavored syrups, honey, and chocolate, all of which contain refined sugars that, once metabolized, cause what many call “sugar crushing.”

Sugar breakdown occurs when you eat too much sugar at one time and the body produces insulin to compensate, causing blood sugar (sugar) levels to drop dramatically. Blood sugar recharges the body and increases energy, which is one of the reasons why people prefer to drink coffee before exercise. This drop in blood sugar levels causes drowsiness, a feeling of sluggishness. Sugar failure can also cause anxiety, mood swings, dizziness, and hunger.

To avoid this effect, try to limit the amount of sugar you add to your coffee and the amount of sugary drinks you consume each day. If you are experiencing sugar depletion, you can counteract this effect with a healthy breakfast such as nuts, seeds, hard-boiled eggs, or yogurt.

4. Tolerance to caffeine
   Over time, heavy coffee drinkers may develop a tolerance to caffeine. Caffeine prevents adenosine from binding to receptors. However, to counter this, the body can start producing more adenosine receptors. One study found that physically active adults experienced less of the effects of caffeine after 15 days of regular consumption.

However, studies on caffeine tolerance have not been conclusive, as other studies have shown that regular consumption does not alter absorption rates or metabolism.

5. Many coffee beans contain mushrooms
   A recent study found that some coffee samples contained mycotoxins such as aflatoxin B1 and ochratoxin A. Although these levels are below legal limits and considered safe for human consumption, other studies have found that mycotoxins can cause chronic fatigue syndrome.