36 Amazing Benefits (and Side Effects) of Coffee – A Balanced View Based on Science (Part 1)

By Jacky Miller

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

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?

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.)