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.
Coffee has many clear health benefits, but also side effects especially if over-consumed. Here we present a balanced view backed by the latest scientific research.
- Health benefit #1: Coffee increases your energy level
- Health benefit #2: Coffee improves your physical performance
- Health benefit #3: Coffee can reduce post-workout pain
- Health benefit #4: Coffee can lower the chances of Alzheimer’s disease
- Health benefit #5: Coffee can lower the risk of Parkinson’s disease
- Health benefit #6: Coffee can help fight off depression
- Health benefit #7: Coffee can lead to a healthier liver
- Health benefit #8: Coffee can protect against gallstones
- Health benefit #9: Coffee can lower risk of Type 2 diabetes
- Health benefit #10: Coffee can protect against heart failure
- Health benefit #11: Coffee is the top source of antioxidants for Westerners
- Health benefit #12: Coffee can protect against retinal damage
- Health benefit #13: Coffee has positive effects against colorectal cancer
- Health benefit #14: Coffee can reduce risk of skin cancer
- Health benefit #15: Coffee prevents cavities
- Health benefit #16: Coffee can make your DNA stronger
- Health benefit #17: Coffee can lower the risk of incident gout in men
- Health benefit #18: Coffee is full of important nutrients
- The Flip Side
- Negative effect #1: Coffee can lead to insomnia
- Negative effect #2: Coffee interacts with and alters medication
- Negative effect #3: Coffee can aggravate heartburn or acid reflux
- Negative effect #4: Coffee can cause indigestion
- Negative effect #5: Coffee can be a laxative
- Negative effect #6: Coffee can contain cancer-causing substances
- Negative effect #7: Coffee can hinder ability of platelets
- Negative effect #8: Coffee can reduce chances of pregnancy
- Negative effect #9: Coffee raises cholesterol
- Negative effect #10: Coffee can cause osteoporosis
- Negative effect #11: Coffee decreases absorption of iron
- Negative effect #12: Coffee can cause fibrocystic breast disease in women
- Negative effect #13: Coffee can irritate your digestive tract
- Negative effect #15: Coffee can increase risk of miscarriage
- Negative effect #16: Coffee can increase risk of hypertension
- Negative effect #17: Caffeine can cause incontinence in women
- Negative effect #18: Coffee can lead to sugary diets
Health benefit #1: Coffee increases your energy level
This is probably the most obvious of coffee. People drink it to feel less tired.
It is because caffeine is a stimulant drug. When you consume coffee, the caffeine is absorbed into your bloodstream. It then travels to the brain where it blocks the neurotransmitter adenosine.
Adenosine is an inhibitory neurotransmitter. Though it helps in energy transfer, it acts as a depressant of your central nervous system. This means it suppresses arousal and promotes sleep. Usually, the levels of adenosine in your brain rises each hour you’re awake, making you more and more sleepy.
When blocked, other neurotransmitters such as norepinephrine and dopamine increase. This is what causes the stimulant effect. Firing of neurons is increased. As a result, you’re more awake.
Many researches show that coffee improves: memory, mood, reaction speed, vigilance and general cognitive function.
So in addition to increasing your energy level, coffee also makes you . . . well, smarter.
Health benefit #2: Coffee improves your physical performance
When caffeine stimulates your nervous system, it goes on to send signals to other parts of your body. Fat cells are signaled to break down body fat.
In short-term coffee drinkers, caffeine can specifically burn fat. Studies have shown that it can burn as much as 29% fat in lean folks and 10% for obese folks. When the fat is released into the bloodstream, they become free fatty acids. You can then use them as fuel.
With slight variance amongst different types of coffee, coffee can boost metabolic rate by 3-11% too.
But more importantly, caffeine increases the adrenaline levels in blood. You know the adrenaline rush that makes you want to run for hours? The purpose of this hormone is to ready your body for intense physical exertion.
Put all of this together, and you can improve your physical performance by drinking coffee.
Next time you head off to the gym, try a cup of black coffee before you go!
Health benefit #3: Coffee can reduce post-workout pain
Not only can coffee help you work out better, it also takes care of you afterward.
Some people say no pain, no gain. But soreness isn’t always good after working out. To reduce the pain, try drinking two cups of coffee.
In a double-blind, placebo-controlled experiment, participants consumed drinks after their muscles were stimulated with eccentric exercise. With this type of exercise, your muscles will elongate due to the opposing force.
One hour after drinking, pain intensity was calculated using a 0 to 100 scale. Caffeinated coffee produced a large decrease in sensitivity to pain.
According to the findings, drinking around 2 cups of brewed coffee after exercise will help greatly with pain reduction.
Health benefit #4: Coffee can lower the chances of Alzheimer’s disease
Alzheimer’s disease, also known as “old-timer’s disease” usually affects seniors over the age of 65 years old. It is the leading cause of dementia. It is also the most common neurodegenerative disease worldwide.
It is an irreversible brain disorder. Gradually, those with Alzheimer’s lose their memory skills, thinking skills and ability to carry out basic tasks.
Sadly, there is no known cure yet. However, there are many preventive steps you can take. They include the usual advice for having good health: a healthy diet, regular physical and mental exercise etc.
But drinking coffee has made the list too.
Many studies show that coffee drinkers can have as much as a 65% lower chance of getting Alzheimer’s disease. In one study with 54 participants, caffeine intake was associated with a drastically lower risk. This was independent of other factors as well.
Health benefit #5: Coffee can lower the risk of Parkinson’s disease
After Alzheimer’s disease, Parkinson’s is the second most common neurodegenerative disease. And as with Alzheimer’s, there’s no known cure yet either.
This disease is caused when neurons generating dopamine in the brain die. Coffee drinkers have been found to reduce the risk by around 32% to 60%.
However, those who drink decaf don’t seem to have any change in risk. This may be because caffeine has a positive effect on dopamine neurotransmitters.
In addition to prevention, coffee may also help those already suffering from Parkinson’s. According to the Research Institute of the McGill University Health Centre, caffeine may help control movement.
Health benefit #6: Coffee can help fight off depression
As mentioned before, caffeine boosts dopamine levels in the bloodstream. Dopamine is a neurotransmitter responsible for movement, memory and cognition. However, it also plays a role with feeling pleasure.
This may be a reason why coffee seems to help fight off depression. A study by Harvard showed that women who drank coffee had a 20% lower chance of having depression. Another study that followed 208,424 people found that those who drank coffee were 53% less likely to be suicidal.
For both studies, the magic number was 4 (or more) cups.
So the bottom line is, coffee may lower the risk of developing depression and helps improve your quality of life.
Health benefit #7: Coffee can lead to a healthier liver
While alcohol will kill your liver, coffee can have positive effects on the organ. The liver is responsible for hundreds of functions to keep the body operating. The diseases that can affect the liver are numerous as well. They include hepatitis, fatty liver disease and more.
Many of these will lead to cirrhosis. Your liver is mostly replaced by scar tissue with this dreadful condition. Thankfully, coffee may be a weapon against cirrhosis. Drink 4 or more cups every day and you may lower your risk by about 22%. It was concluded that an ingredient in coffee is especially helpful against alcoholic cirrhosis.
This was reinforced by another research. It showed that drinking two or more cups every day can reduce chances of death from liver cirrhosis by about 66%.
What other positive effects does coffee have on your liver?
Dr. Carlo La Vecchia and other researchers from Milan, Italy found that drinking all that coffee can lower the risk of liver cancer too.
Regular drinking of coffee may reduce risk of primary sclerosing cholangitis. PSC is a rare disease that affects your liver’s bile ducts.
Decaf coffee can lower liver enzyme levels, as shown by a study in the medical journal Hepatology. Not all benefits are due to the caffeine!
Health benefit #8: Coffee can protect against gallstones
Gallstones are solid pieces that form in your gallbladder, which is right under your liver. If they block a bile duct, it’ll cause immense pain.
These stones can be formed due to your diet (too much cholesterol), gallbladder problems (it can’t empty properly) or medical conditions, such as cirrhosis.
Caffeinated coffee can help prevent these factors, and can prevent gallstone formations.
A study tracked the coffee consumption and development of gallstones of 46,008 men for 10 years. It was found that those who drank regularly had a decreased risk of gallstone formation.
Another study with women found similar results.
Health benefit #9: Coffee can lower risk of Type 2 diabetes
Type 2 diabetes is a serious health problem worldwide. It affects about 300 million people. Those afflicted are either unable to produce insulin or are insulin resistant. This leads to elevated blood sugar levels.
Coffee seems to reduce the risk of developing type 2 diabetes. Studies show a general decrease in risk from 23% to 50%. But one study showed a reduction of up to 67%! A review of 18 studies and a total of 457,922 participants showed that with each cup you drink daily, you can lower your chances of diabetes by 7%.
This was proved by a Harvard School of Public Health review too. HSPH researchers gathered data from three other studies. Questionnaires were used to evaluate the diets of the participants every four years. 7,269 participants had type 2 diabetes and had to file additional questionnaires.
Those who drank one more cup per day over the four years had an 11% lower risk. Those who didn’t change their level of intake had no change in risk.
Researchers at UCLA have found that that consuming coffee has an effect on sex hormone-binding globulin (SHBG). This protein controls the activity of testosterone and estrogen. These sex hormones are present in the development of type 2 diabetes.
One of the study’s authors, Dr. Simon Liu, noted that there’s an inverse association between coffee consumption and risk for type 2 diabetes. By increasing the plasma levels of SHBG, coffee may inhibit the development of diabetes.
Health benefit #10: Coffee can protect against heart failure
Moderate consumption of coffee has been found to protect against heart failure. Doesn’t caffeine increase blood pressure? So how can coffee help with heart disease and stroke?
The key word here is “moderate.” In the study by the Beth Israel Deaconess Medical Center and HSPH, “moderate consumption” per day is:
2 Europeans cups –or—
2 8-ounce American servings
Coffee can increase blood pressure, but only by about 3-4 mm/Hg. This is a small effect. It can go away too if you’re a regular drinker, as your body becomes used to the caffeine.
Women who drink coffee have shown evidence of reduced risk of heart disease. In addition, there are some studies that show a 20% lower risk of stroke in coffee drinkers. This may be due to the antioxidants in coffee.
Health benefit #11: Coffee is the top source of antioxidants for Westerners
This is one of the reasons why some say that coffee is the healthiest beverage ever.
Both caffeinated and decaf coffee have around the same levels of antioxidants. Which is more than the amount you can get from both fruits and vegetables combined (in a typical Western diet).
What can antioxidants do to help your health?
They fight against the free radicals in your body. Most notably, they lower your risk of developing oral cancers. Oral cancers include mouth and upper throat cancers. It was found that older adults who were regular coffee drinkers were half as likely to die of these cancers.
Decaf coffee also had a similar effect, albeit weaker. Tea had no protective effect.
Joe Vinson from the University of Scranton noted that coffee is the number one source of antioxidants for Americans. But moderation is still key here!
Only one or two cups will suffice. Anything more seems to be the opposite of beneficial.
Health benefit #12: Coffee can protect against retinal damage
Of all the antioxidants, the strongest is chlorogenic acid (CGA).
A Cornell University study showed that this great component of coffee reduced death of retinal cells induced by hypoxia or oxidative stress.
CGA and coffee extracts were tested in mice that had an optic nerve crush procedure. It showed similar results.
Drinking coffee may help prevent retinal degeneration as well. Retinal degeneration affects millions of people worldwide. The most common diseases are Retinitis Pigmentosa (RP) and Age-related Macular Degeneration (AMD). Treatments include gene therapy, optogenetics and cell transplants.
With all of these on the list, it’s nice that something as simple as drinking may help prevent the need.
Health benefit #13: Coffee has positive effects against colorectal cancer
In modern society, cancer is one of the leading causes of death worldwide. Drinking coffee can protect you against two types: liver cancer and colorectal cancer. Respectively, they are the third and fourth leading causes of cancer death in the world.
The positive effects of coffee on your liver has already been discussed above. Coffee drinkers show a 40% lower risk of developing this cancer.
In addition, there was a study done with 489,706 participants. Those who drank around 4-5 cups of coffee every day had a 15% lower risk of developing colorectal cancer.
Health benefit #14: Coffee can reduce risk of skin cancer
Basal cell carcinoma is the most common form of skin cancer. In fact, BCC is the most common form of all cancers.
Basal cells are in the deepest layer of the outer skin. With this disease, you’ll see lesions that grow in the cells. They look like open sores or red patches. Though this cancer usually isn’t life-threatening, it can lead to disfiguration.
In a study that used data from the Nurses’ Health Study and Health Professionals Follow-up Study, caffeine intake lowered the risk of BCC. Women who drank more than 3 cups per day had the lowest risk.
In addition, there were similar results with those who consumed tea, cola or chocolate rather than coffee for caffeine.
However, the study didn’t find any change in risk for other skin diseases, such as squamous cell skin cancer. Another study though, found leadings that coffee may help prevent melanoma, the leading cause of skin cancer death. The evidence is limited, but it is still good news!
Health benefit #15: Coffee prevents cavities
Cavities are a very common type of dental problem. You are usually told to just brush well and floss regularly.
But a study found that coffee may help prevent cavities too!
Random samples were taken of those who visited the Out-Patient Department of KLE Society’s Institute of Dental Sciences. The following were taken into factor, in regards to coffee intake:
Frequency and period of consumption
With or without milk
With or without sugar
Brand of coffee
And in addition to consumption of coffee; diet, sweets and brushing were also taken into consideration.
In the end, the results showed that most people drank about three cups of roasted coffee per day. Those who drank it black had the lowest amount of cavities and other dental issues.
However, once sweeteners, creams and/or milk were added, the antibacterial effect was completely minimized.
Health benefit #16: Coffee can make your DNA stronger
Sometimes, your DNA strands will break.
Double-strand breaks happens when side products of cell metabolism causes lesions on DNA and blocks replication. This is lethal for cells if not repaired.
And if repaired incorrectly, there can be deletions, fusions of translocations in DNA. These rearrangements are commonly found in cancer cells.
Your body has evolved to have checkpoint mechanisms.
But another good news is that coffee consumption can strengthen your DNA and make it less susceptible to breakages.
A study was done analyzing healthy men who drank either coffee or water for four weeks. At the beginning, both groups had similar levels of spontaneous DNA breaks. Later, the water only group saw an increase while the coffee group had a decrease. There was a 27% total difference.
The coffee used in this study was dark roast coffee blend.
In addition to less DNA breaks, coffee can also decrease oxidative damage in white blood cells.
Health benefit #17: Coffee can lower the risk of incident gout in men
Gout is a common and complex form of arthritis. It’s more likely to affect men, giving them sudden and severe pains, mostly in the big toe area. Women can also become susceptible to it after going through menopause.
In the most extreme situations, joints can be permanently damaged. It can also affect kidneys, sometimes causing kidney stones.
Researchers studied 45,869 men for over 12 years. Their intake of various drinks (caffeinated coffee, decaf coffee, tea, total caffeine) was analyzed with questionnaires. Additional questions from the American College of Rheumatology were used as criteria for gout.
There were 757 total cases of gout in the study. However, increasing coffee intake led to a decrease in risk of gout. The highest amount of consumption was more than 6 cups per day. (But remember that too much coffee per day can lead to other problems!)
Decaf coffee had some effects as well, but tea had no association.
Health benefit #18: Coffee is full of important nutrients
Coffee is more than just caffeine (and antioxidants)!
A large majority of the nutrients in the coffee beans remain in the drink and are absorbed by our bodies.
Let’s see what is in one cup of coffee:
Vitamin B2 (riboflavin): 11% of RDA
Vitamin B5 (pantothenic acid): 6% of RDA
Manganese and potassium: 3% of RDA
Niacin and magnesium: 2% of RDA
It might not seem like much, considering how other beverages can have much higher percentages. But this is only for one cup! For regular drinkers, 3-4 cups per day is the norm.
Coffee beans are also rich in indigestible bits, also known as dietary fiber. A decent amount passes into brewed coffee. Different methods of brewing were tested, such as espresso, filter and soluble, or with a coffee maker. All results showed that brewed coffee had more soluble dietary fiber than other common beverages.
Soluble dietary fiber forms a gel-like material when dissolved in water. It passes through your systems and helps lower glucose levels and blood cholesterol. This may be why coffee helps with preventing colorectal cancer.
In addition, a high fiber diet can help you:
Ease bowel movements
Maintain bowel health
Achieve healthy weight
And what doesn’t coffee have much of? Calories. (If you only drink it black without any sugary additives, that is.)
The Flip Side
But coffee definitely isn’t the healthiest beverage out there. Or rather, the key (as mentioned before) lies in the amount of coffee you drink. And what you put in there. If you have a sweet tooth, unfortunately have bad coffee, or drink too much, it can lead to some serious side effects.
As you probably know, caffeine can raise your blood pressure. It’s harmful for pregnant women. It’s also a drug, which can be addicting.
If you become dependent, you’ll need more and more to experience the same effect.
And if you try to quit cold turkey, you’ll probably get horrible headaches and mental fatigue for a couple of days.
What else should you be wary of?
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.
For a good night’s rest, try to avoid drinking coffee late in the afternoon. Or at least 2-3 hours before going to bed.
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.
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.
Some other drugs that interact with caffeine include:
So make sure you consult with your doctor or pharmacist to see what’s necessary for you!
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.
A 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.
Other foods that can exacerbate IBS symptoms include:
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.
Coffee has significant health benefits, and also some negative side effects especially if you drink too much of it.
The key seems to be moderation. Too much, and coffee may cause anxiety and stress. Just right, and you’ll get the amazing health benefits mentioned above without too much of the negative side effects.
How much is “moderate”? According to studies, you should keep your daily coffee intake under 300 mg. That’s around 3-4 cups of roasted coffee (5 cups of instant).
If you have hypertension, leaky bladder, touchy stomach, or are pregnant, try to avoid coffee altogether. There are many other beneficial drinks out there (although we’d still love a cup of joe!)