The Side Effects of Drinking Too Much Decaffeinated Coffee

You can enjoy a cup of decaf coffee without worrying about negative side effects.
Image Credit: AndrijaP/iStock/GettyImages

Coffee is more than a drink. It contains caffeine — a mind-sharpening productivity drug that can lift your spirits and sharpen your focus. However, if you've had enough of caffeine and still want the taste of coffee, you can try decaf.


Don't worry about decaf coffee's side effects; there's nothing inherently dangerous about it.

Video of the Day

Video of the Day


Decaf coffee, including the chemicals used to extract caffeine, aren't harmful to your body.

Your Brain on Caffeine

For a coffee purist, it might seem like blasphemy to take the caffeine out of coffee. Caffeine works in your body and brain, but its biggest role is in your nervous system.

Coffee's caffeine, some of which is broken down by your body and converted into a chemical called paraxanthine, blocks nerve receptors in your body and brain. Normally, a chemical called adenosine, which is produced throughout the day, would attach to these receptors. When a certain amount of adenosine has attached to receptors, you begin feeling sleepy.

Read more: Is Decaf Coffee Bad for Your Health?


When the receptors are blocked, adenosine can't latch on and you won't feel tired. Your body produces more epinephrine in response, which is another name for adrenaline. Blocking adenosine receptors gives you a big energy boost. According to an article from Villanova University, caffeine causes:

  • Increased heart rate
  • Pupil dilation
  • Increased blood pressure
  • Tightening of muscles
  • Release of sugar from the liver into the bloodstream


Performance Benefits of Caffeine

Caffeine can increase your physical performance as well. According to a 2018 research review published in the Journal of the International Society of Sports Nutrition, caffeine boosts both endurance exercise performance and strength. That means caffeine can help in the gym and while playing a sport.

Caffeine Withdrawal Symptoms

You can reap the benefits of caffeine whether you're running on the treadmill, studying for an exam or chatting with friends. While it's fairly benign, you can become dependent on caffeine. If you're dependent, you'll experience withdrawal symptoms without caffeine, advises an article from MedlinePlus. Withdrawal symptoms include:



  • Headache
  • Nausea
  • Drowsiness
  • Irritability
  • Trouble concentrating

These withdrawal symptoms are uncomfortable, and the only way to get rid of them is to either wait until they go away or to have more caffeine. In this way, caffeine can be very addictive. It can also mess with your ability to sleep.

Caffeine Disrupts Sleep

The half-life of caffeine is about four hours, according to an article from the European Food Safety Authority, although this number varies from two to eight hours depending on the person. That means it takes about four hours to cut the amount of caffeine in your system by half.


Drinking too much coffee throughout the day or drinking it close to bedtime can make you lose sleep. On top of that, the sleep you do get tends to be lower in quality.

Switching to Decaf

When you feel the negative side effects of caffeine, you might want to lower your intake. If you're afraid to go cold turkey on coffee you can drink decaf, which has much less caffeine than regular coffee.


Read more: What Are the Health Benefits of Drinking Decaffeinated Coffee?

Taking Caffeine Out of Coffee

The concern with decaf doesn't seem to be the coffee itself — it's how the caffeine is extracted. On the surface it seems worrisome, because chemicals are often used. Decaf coffee has caffeine, but only a very small amount. In order to qualify as decaf, the beans must have 97 percent of their caffeine removed.


The decaffeination process was pioneered by Ludwig Roselius, who originally soaked green, unroasted coffee beans in water to extract caffeine. He then used benzene to more efficiently extract the caffeine.


Indeed, water was the original tool to extract caffeine from coffee beans. The problem is that it not only sucks out the caffeine, it sucks out other chemicals that give coffee taste and color.

Different Extraction Methods

Over the years, this process has evolved to include a few different methods. Chemicals, carbon dioxide and even a more advanced water-based method have been developed, all of which are safe. Each process starts with green coffee beans, which haven't been roasted. There's no difference between regular beans and decaf coffee beans before the extraction process.

Chemical Extraction Process

Methylene chloride and ethyl acetate are the main chemicals used in the process of extracting caffeine from coffee. They're harmless, but some of the chemicals previously used in this process might not have been.

In fact, methylene chloride can be harmful to your lungs if you breathe it in. Thankfully, it's harmless to ingest in the amounts used, and the chemical is mostly destroyed when the beans are roasted — so there aren't any side effects from the chemicals.

Swiss Water Process

The Swiss Water Process is a unique method of extracting caffeine from green coffee beans. It's the most natural method of extraction and only uses water, so there won't be any side effects from chemical ingestion.

Carbon Dioxide Extraction

Using liquid carbon dioxide, this recently developed method extracts the caffeine from green coffee beans by soaking them in a water and carbon dioxide mixture. The mixture is pressurized to about 1,000 pounds per square inch to extract the caffeine. The liquid is then drained and heated to release the carbon dioxide, leaving the caffeine behind.


Decaf or Regular Coffee?

As stated, the modern methods of extracting caffeine from beans hardly use any chemicals. Even if they do, the chemicals are benign.

Decaf coffee might be either better or worse than regular coffee, depending on how you look at it. If you're having adverse effects from drinking too much caffeine, then switching to decaf is better for your body. Plus, decaf still contains healthy polyphenols and antioxidants found in coffee.

Some studies have examined the specific health benefits of polyphenols and antioxidants extracted from coffee. Researchers have found that they can help prevent diabetes and high blood pressure, and even show some anti-cancer benefits. However, caffeine has health benefits of its own.

Health Benefits of Caffeine

An article from Michigan State University explains the benefits of caffeine:

  • Protects brain cells, which can help prevent diseases like Parkinson's
  • Stimulates the gallbladder to reduce risk of gallstones
  • Can reduce pain from headaches
  • Reduces inflammation and risk of heart problems

Without the caffeine in your coffee, you're potentially missing out on these benefits. It's up to you to decide whether or not the caffeine is worth it.

The Taste of Decaf

Some extraction techniques, particularly those that use chemicals, may alter the taste of decaf coffee. You'll have to compare different brands and different methods of extraction to find your preferred taste.