18 Side Effects of Coffee

18 Side Effects of Coffee


This article first appeared on Jen Reviews. What is the most used drug in the world? It’s not nicotine or anything illegal. It is caffeine. And the most popular form it comes in is coffee. Many people joke that they can’t function without coffee. Others hate it. 

18 Side Effects of Coffee


This article first appeared on Jen Reviews. What is the most used drug in the world? It’s not nicotine or anything illegal. It is caffeine. And the most popular form it comes in is coffee. Many people joke that they can’t function without coffee. Others hate it. 

Negative effect #1: Coffee can lead to insomnia


While caffeine raises your energy levels, the effect is detrimental when you’re trying to sleep.

Caffeine enters your bloodstream after digestion. Its stimulating effect can be felt 15 minutes after consumption. However, the effect will last for much longer. It will take around 6 hours for even half of it to be eliminated.

Negative effect #2: Coffee interacts with and alters medication


If you take medication, make sure you check with your doctor before drinking coffee with it! Your drink might interact with prescription drugs. The effect from your medication may be decreased, increased or changed.

The culprit may be the caffeine or other compounds in your coffee.

For example, a study was done concerning Fosamax (an osteoporosis drug scientifically known as alendronate) taken with water or other beverages. Apparently, taking it with black coffee or orange juice would reduce the absorption by 60 percent! For best results, you should take it with water on an empty stomach when you start the day.

The effect of thyroid medication is reduced by 55 percent when taken with coffee or espresso.

In addition, it can go the other way. Your prescription drugs might increase the effect of your coffee. You can feel the caffeine buzz for longer. Or, they may have the same goal and give you double the effect, as is the case with antidepressant drugs.

Negative effect #3: Coffee can aggravate heartburn or acid reflux


Acid reflux symptoms include heartburn, a burning pain in your chest. This happens when your lower esophageal sphincter (LES) at the entrance of your stomach doesn’t close when it should. The acid your stomach produces can then move into your esophagus.

If these symptoms happen at least twice a week, you may have acid reflux disease. And if that’s the case, make sure you stay away from coffee!

Coffee is highly acidic. Add caffeine to the acid content, and it will cause your LES muscles to relax. This can lead to, or worsen, your acid reflux conditions.

Even decaf coffee is a danger. In fact, some studies have found that decaf actually increases stomach acid levels. Compared to caffeinated coffee, decaf coffee stimulates the release of more gastrin. This is the hormone that then goes on to stimulate the release of stomach acid.

Other beverages to be wary of are tea (caffeinated or decaf), citrus fruit juices, milkshakes and alcohol.

Negative effect #4: Coffee can cause indigestion


When you drink your cup of joe on an empty stomach, it stimulates production of hydrochloric acid (HCl), which can be a serious problem.

Your stomach usually produces HCl when you eat. Its function is to digest protein and/or fat that you ingest. When acid is overproduced, lower levels are produced when we really need it.

This can happen when we eat too many fats and proteins. Or when we drink too much coffee on an empty stomach. This situation affects protein digestion particularly. When protein isn’t digested properly, a host of problems can occur.

On the lighter side, protein indigestion can cause bloating, gas and discomfort. But on the extreme side, it can cause IBS or even colon cancer. So make sure you don’t grab a cup of coffee first thing in the morning!

Negative effect #5: Coffee can be a laxative

Coffee stimulates movement of colonic muscles.

This promotes peristalsis, which is the digestive process and muscle contractions that makes you need to go number 2.

Maybe that sounds okay, or even good. If you ever need a laxative, just go for coffee! But it can be a problem. Especially if you don’t have constipation or any related needs.

While coffee stimulates peristalsis, it seems to also stimulate gastric emptying. In a study with 93 participants, 73% experienced accelerated emptying.

This causes whatever is in your stomach to pass into your small intestines. Before the food can be properly broken down and digested.

It’s much harder for nutrients to be absorbed from partially digested food. This situation can also increase chances of gastrointestinal irritation and inflammation. Aside from this effect on your bowel, increased peristalsis can make it harder for the colon to reabsorb water from waste products.

The caffeine isn’t the only thing to blame here either. Decaf coffee has also been found to have these laxative and gastric emptying properties. What you add into your coffee (cream, sugar, sugarless sweeteners etc.) can cause diarrhea as well.

Negative effect #6: Coffee can contain cancer-causing substances


Coffee has been found to have positive effects against certain cancers. However, when coffee beans are roasted at high temperatures, acrylamide can form.

Acrylamide is both carcinogenic and genotoxic. This means it can potentially cause cancer and damage the genetic material of cells.

While many foods contain dangerous levels of acrylamide (such as fries and burnt toast), coffee seems to a major source of this chemical. The darker the roasted beans are, the higher the levels. Lighter beans may reduce the exposure, but you can’t avoid it completely.

Negative effect #7: Coffee can hinder ability of platelets


Platelets are cell fragments produced in your bone marrow.

They play the biggest role in stopping bleeding. The proteins on their surface allow them to stick to each other and blood vessel walls. They effectively become a plug in openings to stop blood from rushing out.

In 2008, a study was done on the effect of coffee and caffeine on platelets. The participants either consumed coffee or a caffeine capsule and water. The ones who only drank coffee experienced an anti-platelet effect. Their platelets had a decreased ability in sticking together.

The subjects who only had caffeine saw no change. So it seems that something else in the coffee is the culprit (and drinking decaf won’t really help). This can potentially be fatal if you are anemic or have other blood-clotting disorders.

Negative effect #8: Coffee can reduce chances of pregnancy


According to researchers from the University of Nevada School of Medicine, the activity of Fallopian tubes is decreased by regular caffeine intake.

These tubes carry eggs from the ovaries to the uterus. We still don’t know much about how eggs travel through these muscular tubes. But experts say it has something to do with cilia along the lining of the tubes and muscular contractions.

For a successful pregnancy, the eggs must make it through the tube to the womb. However, in the research done with mice, there was much less contractions when the mice consumed caffeine.

Though the subjects were mice, Professor Sean Ward thinks this can explain why women with high caffeine consumption aren’t as likely to become pregnant.

If you, or a loved one, have been unsuccessful with pregnancy, maybe coffee is the culprit.

Negative effect #9: Coffee raises cholesterol


Cholesterol is a fatty substance needed to produce hormones, vitamins and other essential substances. There are two types: low-density (LDL) and high-density lipoproteins (HDL).

You should have healthy levels of both types for your body to function. However, LDL is also known as the “bad” cholesterol. That’s because too much of it can lead to buildup in your arteries. That causes a variety of heart and blood pressure problems.

Cholesterol levels can be elevated by cafestol though. According to Professor Dr. David Moore, cafestol is the most powerful cholesterol-elevating substance out there. And unfortunately, it is a compound found in coffee.

study found that five cups of French press coffee contained 30 mg of cafestol. After consuming five cups per day for four weeks, blood cholesterol was raised from 6 to 8 percent.

Drinking decaf coffee doesn’t make any difference in the effect. The good news though, using paper filters during the brewing process can remove a good portion of cafestol. So make sure you use those paper filters!

Negative effect #10: Coffee can cause osteoporosis


Osteoporosis is a serious and costly bone disease. It occurs when too much bone is lost and/or too little is made. Bones lose density and start to look like a honeycomb. Bones become brittle and frail. In serious cases, you can break a bone merely from sneezing!

This disease is extremely dangerous for senior citizens, causing permanent pain. You are especially perceptible if you have low bone density to begin with. And as multiple studies show, caffeine may be a factor too.

Calcium is crucial for healthy bones. And caffeine can decrease the efficiency of calcium absorption. A study found that for every cup of joe you drink, you can lose around 4-6 mg of calcium. Another study found that caffeine can lead to accelerated loss of bone mineral density in elderly women.

But in most studies, many cups of coffee and low calcium intake were needed for this negative effect. To be on the safe side, especially for older folks, try to limit yourself to three cups per day and eat a lot of calcium and vitamin D!

Negative effect #11: Coffee decreases absorption of iron


Coffee can be in the way of getting enough minerals into your body. Even if you have a mineral-rich diet and/or take supplements. As aforementioned, calcium absorption is affected.

In addition, your kidneys will have difficulty retaining zinc and magnesium. Magnesium is needed for bowel regularity. And your stomach’s absorption of iron might decrease too.

Iron is needed to form hemoglobin. This protein, part of your blood cells, carries oxygen from your lungs to the rest of your body. Depending on the source of the iron, it can be either heme or non-heme iron.

Phenolic compounds in your coffee binds to non-heme iron. This inhibits its absorption. It was found that drinking 150-250 mL of coffee can decrease absorption by around 35 percent.

Tea has an even greater effect, decreasing absorption up to 64 percent. On the other hand, studies have found that orange juice led to an 85 percent increase.

If you’d like to up to your iron intake, try switching out your joe for some juice.

Negative effect #12: Coffee can cause fibrocystic breast disease in women


If you’re a woman, maybe you’ve experienced swollen or painful breasts. It could be fibrocystic breast disease. This benign breast disease usually shows through lumps in your breast that becomes larger before periods. And it can hurt!

The exact cause of this disease is unclear. It may be hormones during menstruation.

And according to a hospital-based study, women who drank 31 to 250 mg of caffeine per day had a 1.5 fold increase in risk. Caffeine intake can increases the risks up to 2.3 folds.

This relationship was especially strong in women with atypical lobular hyperplasia or papillary hyperplasia. These are both associated with higher breast cancer risk as well.

Caffeine intake, however, had no negative effect on other types of benign breast disease.

If you experience painful swelling, lumps or irregularities near your breasts, make sure to call your physician!

Negative effect #13: Coffee can irritate your digestive tract


Coffee is extremely acidic, thanks to components like caffeine (although decaf coffee leads to greater increase of acidity). It will irritate the lining of your small intestine and stomach.

If you are suffering from gastritis, ulcers, Crohn’s disease or IBS, doctors strongly recommend avoiding coffee completely. Coffee might be responsible for causing these problems in the first place.

One cause of ulcers is the Helicobacter pylori bacteria. The acid in coffee weakens stomach lining. This gives fertile ground for the bacteria to take hold of. A strong immune system can protect you. But stress hormones might suppress your immune system.

In the small intestines, coffee can wreak havoc on the lining. You can end up with abdominal spasms, cramps, constipation and/or diarrhea.

This condition is known altogether as irritable bowel syndrome (IBS). This is becoming an urgent problem in recent years as more and more people are diagnosed with it.

Negative effect #14: Coffee can promote stress and anxiety


Caffeine promotes the release of epinephrine, norepinephrine and cortisol. These hormones stimulate the “fight or flight” response. Now, you may be wondering, “Isn’t this a good thing?”

Well, yes. Coffee raises your energy levels and wakes you up. But everything has pros and cons. The downside of this is that the energy can be a bit too much.

Rather than just feeling awake, you might start feeling anxious and jittery. The tension just won’t go away!

Caffeine does this by blocking release of Gamma-aminobutyric acid (GABA).

This neurotransmitter is known as the brain’s natural Valium. It’s a calming inhibitor. It gets rid of the worrying thoughts in your mind. Experts believe that, along with serotonin, GABA helps your brain control anxious thoughts.

When things like caffeine stop GABA from being released, you can feel terrible distress and anxiety.

Negative effect #15: Coffee can increase risk of miscarriage


And the scary thing is, this doesn’t just pertain to women!

The National Institutes of Health and Ohio State University analyzed data examining 501 couples from 16 counties in USA.

The relationship between exposure to chemicals in the environment, lifestyle and fertility were looked at.

It was found that miscarriage was more likely if the couple drank more than two caffeinated beverages per day before conception. Both male and female caffeine intake contributed to this raised danger.

Likewise, women who drank during the first seven weeks of pregnancy also had an increased risk.

To insure a healthy pregnancy and baby, avoid caffeine consumption and smoking. Instead, consider taking daily multivitamins.

The researchers found that women who took vitamins through early pregnancy lowered their risk of miscarrying by 79 percent!

The major vitamins are vitamin B6 and folic acid.

They’re usually found in preconception and pregnancy vitamin formulas. Folic acid especially helps protect the child from developing a neural tube defect.

Negative effect #16: Coffee can increase risk of hypertension


You can have hypertension, or high blood pressure, for years without seeing any symptoms.

Even without symptoms, your blood vessels and heart are still damaged. It can lead to serious health problems, such as stroke or heart attacks. And even without symptoms, hypertension can still be detected.

Coffee may help with heart problems. But for young adults with hypertension, the joe may make things worse.

According to research presented by the Hospital of San Daniele del Friuli, heavy coffee drinkers saw a four-fold increase in risk.

Moderate drinkers had a three-fold increase. The study spanned 12 years, analyzing more than 1,200 patients from 18-45 years old with untreated stage 1 hypertension.

High blood pressure often leads to diabetes. The researchers found that heavy coffee drinking led to a higher risk of prediabetes. However, it was only significant increase for slow caffeine metabolizers. So maybe that’s good news?

Negative effect #17: Caffeine can cause incontinence in women


Urine incontinence (UI) is also known as the “leaky bladder.”

With this condition, you lose control of your bladder. And you just can’t hold it in! In extreme cases, even sneezing can make you leak.

We know coffee can act as a laxative. Researchers at the University of Alabama found that it has a similar effect on peeing. The Incontinence Severity Index and food diaries were used by more than 4,000 women.

Caffeine intake of more than 204 mg per day was linked to UI. Thankfully, it wasn’t severe UI.

Still, if you’re a coffee drinker, you know it makes you run to the bathroom a lot more often!

Negative effect #18: Coffee can lead to sugary diets


As we all are aware of, sugary drinks are unhealthy.

Carbonated drinks, fruit juices and other sugar-sweetened beverages (SSB) can lead to type 2 diabetes, obesity and more.

Though we know that, it’s hard to stay away. They’re addictive in their own right.

Caffeine, on the other hand, can make you want them even more.

In a randomized controlled trial, participants drank as much as they wanted of different drinks. One group had drinks containing caffeine. Their diet diaries were then collected and analyzed.

Participants from the caffeine group had a daily SSB intake of 419 ml. This was much more than the non-caffeine group. On average, they only consumed 273 ml per day.

The caffeine group also gave higher ratings to their sugary beverages. The researchers concluded that adding a bit of caffeine into the beverages significantly increases consumption.

Maybe caffeine gives the pop of flavor we need. But drinking less coffee (and other caffeinated drinks) can definitely lead to a healthier diet. The good news, though, is new developments in wearable technology may provide another alternative to coffee.

Also, black coffee is pretty healthy. But once you add milk, cream and sweeteners, the calorie count skyrockets.