Coffee and Health

Coffee is good for you. Every year more and more health benefits of drinking coffee are discovered. But, this view of coffee, based on scientific research, has only recently emerged. Many of us can recall being told by the doctor to cut back on our coffee consumption for various reasons. Humans have been drinking coffee for hundreds of years. And, there have always been concerns about whether coffee is good or bad for us to drink. In fact, as far back as the 1600’s when coffee became popular in Venice, Italy, the local clergy called it the “bitter invention of Satan.” Only the intervention of Pope Clement VIII saved coffee from being banned! (National Coffee Association) Here are some thoughts about coffee and health, why it is good for you, and also when you should cut back on your consumption of Java.

How Coffee Is Good for Your Health

Effects of Coffee on the Heart

Coffee and Health
Coffee Is Good for Your Health

If you drink a lot of coffee, your heart may speed up. And, some people complain of an irregular heart beat after drinking strong coffee. So is coffee bad for your heart? People who drink more than four cups of coffee a day are more likely to experience a fast or irregular heartbeat. (Mayo Clinic) So, if your heart skips or speeds up with lots of strong coffee, cut back a bit. But, the evidence shows that drinking coffee does not damage your heart but is good for it. Coffee drinkers do not have a higher incidence of dangerous heart rhythm problems than those who do not drink coffee. And, coffee drinkers have a lower risk of calcium deposits in and clogging of their coronary arteries!

Mental Health: Coffee Reduces the Incidence of Both Depression and Suicide

We know that coffee is a pick-me-up but there is more to the picture. We have known for several years that drinking coffee reduces the risk of depression. Researchers found that women who drank at least four cups of coffee a day had a lower incidence of depression than women who drank of a cup of coffee a day, or less. The risk reduction was twenty percent and the study included 50,000 women. It appears that the reduction of risk improves with more coffee each day. And, the benefit appears to come from caffeine as decaf drinkers showed no improvement.
(Archives of Internal Medicine, 2011, V. 171)

A slightly more recent study (2013) showed that drinking coffee reduces the risk of suicide. This is a big league scientific study from the Harvard School of Public Health. Over twenty years they followed more than 130,000 men and women, keeping track of coffee consumption and consumption of caffeine in general. The bottom line was that drinking two to four cups of coffee a day reduced the risk of suicide by half! There was a slightly better result with four cups a day than with two. The researchers believed that besides acting as a stimulant, the caffeine in coffee acted as an antidepressant as well.
(The World Journal of Biological Psychiatry)

Drinking Coffee Significantly Reduces the Risk of Type II Diabetes

It has been known for several years that coffee drinkers have a reduced risk of developing type II diabetes. The risk reduction is about seven percent for every cup of coffee consumed per day. As such, drinking six cups of coffee a day reduces your risk of getting type II diabetes by 42%. This happens with decaf coffee as well as caffeinated coffee. The effect is believed to come from the antioxidants in coffee. This is a huge deal!
(JAMA, Journal of the American Medical Association)

coffee and health - diabetes
Coffee Reduces Your Risk of Type II Diabetes

In 1980 there were 108 million people worldwide with diabetes and ninety-five percent had type II diabetes. By 2014 there were 422 million people with the disease and the proportion of type II was the same. This disease is a primary cause of heart attacks, kidney failure, blindness, limb amputation, and stokes. And, drinking coffee reduces your risk of getting it by seven percent for every cup a day that you drink!
(World Health Organization)

Better Athletic Performance after Drinking Coffee

Usually we think of drinking coffee as a sedentary activity. But, it turns out that you can work out harder and even run longer and faster after drinking coffee. Coffee enhances athletic performance.
The bottom line is that coffee may help you pay attention when you are getting tired which should help in sports where that matters like reading the green correctly on the last hole of the Masters after four long days of playing professional golf. And, the adrenaline secreted in response to drinking coffee helps in endurance sports like running and cycling. This effect works just as well in heavy coffee drinkers as it does with those who normally drink no coffee. Coffee drinking does not seem to help strength activities like weight lifting.
(Journal of Applied Physiology)

Is Sex Better Too after Drinking Coffee?

If endurance is necessary for good sex, then drinking coffee ought to work as we noted in the part about coffee and better athletic performance. However, there is more to the story of coffee and better sex.
A study in 2009 showed that in a group of elderly men and women, coffee increased potency in men and libido in women.
(Dr. Bharwani/Archives of Internal Medicine)

Coffee Drinkers Reduce Their Risk of Getting Alzheimer ‘s Disease

The Journal of Alzheimer’s Disease reported a study linking coffee drinking to a reduced risk of dementia and Alzheimer’s disease later in life. This 2009 report looked at 1,409 individuals in Finland who were followed for more than twenty years and reported on their coffee intake, among other things. Of the group of 1,409 people, 61 developed dementia of which 48 were cases of Alzheimer’s disease.

Coffee and Health - Alzheimers
Coffee Reduces the Risk of Alzheimers

When the researchers compared coffee drinkers to those who drank little or no coffee, there was a 65% reduction in the risk of developing Alzheimer’s disease in the coffee drinkers. The maximum benefit occurred in people who reported drinking three to five cups of coffee a day. Those who drank decaf coffee experienced the same level of benefit as drinkers of coffee with caffeine. The consensus of scientists is that it is the level of antioxidants in coffee that is responsible for this benefit.
(Journal of Alzheimer’s Disease)

If you are interested in information about antioxidants and how they may help stave off Alzheimer’s disease, and you don´t mind wading through a lot of science, take a look at an article published in the journal Oxidative Medicine and Cellular Longevity.

They go through a long list of foods and drinks with high levels of antioxidants, including coffee, and discuss the rationale for assuming that each one may reduce the incidence of Alzheimer’s. The one substance that has been shown to make a difference in outcome over a long period of time is coffee!
(Oxidative Medicine and Cellular Longevity)

Coffee and a Reduced Risk of Dying

In our article, Drink Coffee, Live Longer, we report on a study published in the journal Circulation. The ultimate health benefit of drinking coffee is that you reduce your risk of dying from a large number of different diseases in the next few years. The title of the study is a real mouthful, “Association of Coffee Consumption with Total and Cause-Specific Mortality in Three Large Prospective Cohorts.”

Here is a, hopefully, clear explanation of how coffee reduces your risk of dying in the next few years. The Harvard School of Public Health has enrolled Harvard graduates in the health professions in a long term study of health outcomes and lifestyle. This study has gone on for decades and includes more than 167,000 women and 40,000 men.

Over the years, every time they were contacted, people reported how much coffee they drank. They also reported on health issues. And, if they died, the cause of death was found in public health records.
This study looked at 4,690,072 person years (# of people x # of years). During that time 19,524 women and 12,432 men died. When the researchers looked at those who lived and those who died they also looked at reported coffee consumption. The bottom line was that folks who drank from one to five cups of coffee a day had a lower risk of dying during the course of the study than people who were not coffee drinkers.
Cups per day and Lower Risk of Death (over the course of the study)

  • 1 cup: 6%
  • 2 cups: 8%
  • 3 to 5 cups: 15%
  • More than 5 cups: 12%

What was happening was that the coffee drinkers were less likely to develop problems like type II diabetes, heart disease, strokes, or neurologic disease. And they were less likely to become depressed and commit suicide. Thus, the coffee drinkers were less likely to die during the course of the 20+ year study than those who did not drink coffee.

The benefit of drinking coffee was not affected by drinking decaf or regular, did not extend to deaths from cancer, and did not extend to people who smoked!

The Circulation article is very informative and full of lots of science. For a more “readable” version check out a New York Times article that reports on the study, Coffee Tied to Lower Risk of Dying.

Why Does Coffee Reduce the Incidence of Diseases and, Effectively, Prolong Life?

Why is it that drinking coffee has so many health benefits? Two things in coffee have been identified as being helpful, caffeine and antioxidants. We noted in regard to depression and suicide risks that caffeine is what makes the difference. For pretty much all of the rest of the health benefits of coffee it comes down to the antioxidants. The issue that researchers mention time and time again is called “chronic oxidative stress.”

Oxidation and Antioxidants

There are all sorts of densely scientific explanations of oxidation. The short version is that when oxygen combines with something, that something is oxidized. When oxygen combines with iron, the iron rusts. Within the human body oxygen is necessary for life and oxygen can also cause damage to the interior of cells. The sum total of this damage can be seen as oxidative stress.

The “too much” oxidation results in degenerative illnesses and premature aging. The body has a whole host of defense mechanisms to avoid excessive oxidation and oxidative stress, but the addition of antioxidants to the diet is known to help. The body’s antioxidants and those in the foods and drinks we consume help reduce the rate of damage from oxidation. Pretty much all of the health benefits of coffee appear to come from the antioxidants it provides the human body.

A short and useful explanation of oxidative stress explains that because we breathe oxygen we need enzymatic and molecular defenses to guard against oxygen free radicals that cause oxidation. When the body’s defenses are not sufficient, damage occurs to the RNA, DNA, proteins, and other constituents of the body’s cells. The cumulative damage results in damaged cell functioning, cell death, and cancer.
(University of Gothenburg)

Coffee as a Source of Antioxidants

So, is coffee the best source of antioxidants? Coffee is not the richest source of antioxidants but we drink so much of it that coffee is, for most people, their most reliable and important source of antioxidants.
The Nutrition Journal published a comprehensive study of foods and beverages and the antioxidants they contain. Coffee is mentioned in the summary where the authors note the high level of antioxidants and high level of consumption of coffee making it an important source, if not the most important source for most people in the world.
(Nutrition Journal)

What Is the Level of Antioxidants in Your Coffee?

There are antioxidants in green coffee and there are antioxidants created by roasting coffee. Green coffee antioxidants include trigonelline and ferulic, caffeic, chlorogenic, and n-coumaric acids. When coffee is roasted melanoidins, phenylalanines and several heterocyclic compounds are created. All of these are powerful antioxidants. The “take home lesson” here is not the specific names of these compounds but rather the fact that green coffee has antioxidants and by roasting coffee we create more of them!

But, not all coffee varieties have the same level of antioxidants. Stale coffee that has been stored improperly or too long has lower levels of antioxidants. And, coffees from different parts of the world may have different levels of antioxidants as well. How coffee is processed makes a difference as does the method of roasting.

Interesting Findings

  • Green Robusta coffee beans have more antioxidant activity than green Arabica beans, but with light roasting the difference goes away. And, by the time a dark roast is achieved, Arabica exceeds Robusta in antioxidant activity.
  • Microwaving coffee to roast it does a better job of preserving antioxidants than traditional convection roasting.
  • Wet processing of coffee preserves more antioxidants than dry processing.
  • Total antioxidant content was measured for coffees provided by Freshly Roasted Coffee.  Coffees from Guatemala, Brazil, Colombia, Ethiopia, and Puerto Rico ranked the highest and are listed here in descending order.


When Coffee Can Cause Health Problems

Blood Pressure

Caffeine is a stimulant. It can raise your blood pressure. According to the Mayo Clinic, the caffeine in coffee can cause a short term elevation of your blood pressure. It is thought at part of this effect is because caffeine stimulates the adrenal glands to secrete adrenaline which in turn raises pressure. Caffeine may also block the ability of arteries to widen which, in turn, can raise blood pressure.

However, many who drink coffee develop a tolerance to caffeine and their blood pressure no longer goes up with coffee and caffeine consumption. While some regular coffee drinkers experience an elevation of their blood pressure, many do not have any long term problems. According to the good doctors at Mayo, the best course of action is to find out if you do or do not have high blood pressure and, if you do, ask your doctor about how much coffee you can safely drink. If you want to play scientist, take your blood pressure before drinking coffee and again half an hour to two hours after finishing the cup. At Mayo, their opinion is that, in general, you should not have to worry about drinking a couple of 8-ounce cups of coffee a day (200 milligrams of caffeine). But, if you have significant health problems relating to blood pressure, talk to your doctor!
(Mayo Clinic)

Gastritis, Acid Reflux, and Ulcers

Heartburn (reflux of stomach acid into the esophagus) is a common complaint when one drinks too much coffee. Thus, doctors have typically advised against coffee drinking for patients with gastritis, acid reflux, and stomach of duodenal (upper small intestine) ulcers. However, recent scientific analysis shows that there is no proven association between gastritis or ulcers and drinking coffee that contains caffeine! Investigators speculate that other constituents of coffee such as its many antioxidants have protective effects. (Scandinavian Journal of Gastroenterology)  (PLoS One. 2013; 8(6): e6599)

The obvious answer in this case is that if you drink a lot of coffee and get heartburn, cut back until the heartburn goes away! And, for continuing problems in this area, see your doctor.

Coffee and Cancer

Drinking Coffee Helps Prevent Cancer

Recent scientific studies indicate that drinking coffee reduces the risk of developing cancers of the prostate, liver, breast, colon, rectum, endometrium (lining of the uterus), mouth and throat. In general, the benefit goes high with more cups per day consumed up to around 6 cups a day.
(American Cancer Society)

How about Acrylamide?

Acrylamide was in the news when a California court ruled that coffee needed to come with a label warning that it could cause cancer. The key issues here are California Proposition 65, roasting and frying starchy foods, and what constitutes a meaningful risk to the consumer.

California Proposition 65

This California law “requires the state to maintain and update a list of chemicals known to the state to cause cancer or reproductive toxicity.”


According to the American Cancer Society, “Acrylamide is a chemical used mainly in certain industrial processes, such as in making paper, dyes, and plastics, and in treating drinking water and wastewater.
Acrylamide can also form in some starchy foods during high-temperature cooking, such as frying, roasting, and baking. Acrylamide forms from sugars and an amino acid that are naturally in food.”

According to these folks the highest levels of acrylamide are in French fries and cigarette smoke.

The primary evidence for acrylamide as a cause of cancer is from lab rats that were given acrylamide in their drinking water at level 1,000 to 10,000 higher than humans might be expected to be exposed to, ever.
(American Cancer Society)

Court of Appeals Reverses Acrylamide Decision Regarding Cereals

Coffee still needs to come with a warning label in California but according to the California court of appeals decision, breakfast cereals do not despite the fact that a lower court ruled that they do. The bottom line is that Federal policy is to promote cereals with fiber as being healthy and a cancer warning would negate that effort.
(Hogan Lovells Law Firm)

The problem for you as a coffee drinker is this. Do you believe in all of the evidence that coffee is good for you or do you believe that poisoning lab rats with excessive levels of a chemical really applies to you?
An interesting analogy is this. Put a lab rat, or you, in a room with 7 feet (84 inches) of water and nothing to hold on to. You have to tread water to stay alive and will eventually drown and die. That is a 100% mortality rate. If you reduce the water in the room to 1% of that level (0.84 inches) your risk of dying is now virtually zero and certainly not 1%!

It is certainly a worthwhile goal to protect the public against substances that cause cancer. But, in the case of coffee, the scientists find “no convincing evidence” that drinking coffee causes any kind of cancer.
(American Cancer Society)

At we try to keep up with all of the news that relates to coffee and health. And, when we find something important or just interesting we will post the information on our site. If you have questions about the health aspects of coffee, please feel free to leave a comment and we will get back to you. And, if your question is of general interest, we may write an article about it.

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