That morning cup of coffee which so many of us can’t do without may be doing more than just jump-starting our day. Coffee contains over 1,000 compounds which can affect your body in different ways, and research suggests it can have a positive result on your health.
What does coffee have to offer?
The most commonly studied compounds in coffee include caffeine and polyphenols. Caffeine is a stimulant which affects the nervous system and is known to have positive cognitive effects, and polyphenols are antioxidants which can help slow down and prevent cell damage.
1. Protect against Type 2 diabetes
Studies from around the world consistently show that a high consumption of coffee is associated with a lower risk of Type 2 diabetes. One of the most famous studies was conducted in 2014 by Harvard researchers and published in the journal Diabetologica.
Their results showed that over a four year period, participants who increased their coffee intake by more than one cup per day had an 11% lower risk of developing the disease.
Participants who decreased their intake by one cup a day, on the other hand, showed a 17% higher risk of developing Type 2 diabetes.
2. Protect against cardiovascular disease
According to researchers at the Harvard School of Public Health, drinking the equivalent of two 8 ounce (225g) cups of coffee a day can offer protection against heart failure.
Data from several other studies also suggest that drinking 3 to 5 cups of coffee a day can lower the risk of heart disease, compared to consuming no coffee at all or over 5 cups a day.
Although the reason for this still isn’t clear, it’s thought that consuming coffee can improve your blood vessels’ control over blood flow, and that it also benefits your arteries by reducing atherosclerosis.
Drinking coffee can initially raise your blood pressure, but it’s thought that over time your body develops a tolerance to this effect so that the benefits outweigh the risks.
3. Control Parkinson's disease symptoms
Many studies have shown that consuming caffeine can reduce the risk of developing Parkinson’s disease.
A more recent study in 2012 also suggested that a daily dose of caffeine (the equivalent of consuming two 8 ounce cups of black coffee) can help control involuntary movements of individuals who already have the disease.
To get the same levels of caffeine from drinking tea you’d have to drink about 8 cups of brewed black tea.
4. Lower rates of depression
It is thought that the world’s most popular central nervous system stimulant can also help decrease the risk of depression in women. A 2011 study lead by the Harvard School of Public Health suggested drinking 4 or more cups of coffee a lead to a 20% lower risk of depression.
They also determined that consuming decaf, tea, soft drinks, chocolate, and other caffeinated beverages didn’t offer the same protection against depression.
However, it is generally agreed that more research is needed to determine the link between coffee and depression.
5. Slow the progress of dementia
Research suggests that adults in their 40s and 50s who drink 3 to 5 cups of coffee a day could have up to 70% less risk of developing Alzheimer's and dementia in their 70s.
Research carried out in 2009 by the University of Florida studied caffeine blood levels in adults with mild cognitive impairments, which can be a precursor to severe dementia. When they re-evaluated the same individuals 2 to 4 years later, they found those who had blood caffeine levels equivalent to 3 cups of coffee were far less likely to have developed dementia or Alzheimer's disease, compared to those who consumed little or no caffeine.
6. Safeguard the liver
Coffee is also known to have beneficial effects on the liver. Several studies suggest that drinking coffee helps decrease harmful liver enzyme levels, can limit liver scarring in people suffering from Hepatitis C, and reduces the risk of death from liver cirrhosis.
Regularly drinking a moderate amount of coffee may also help prevent liver cancer and lower the risk of conditions such as fibrosis. It seems to have beneficial effects no matter how the coffee is prepared, such as espresso, filtered, or instant.
7. Reduce risk of certain types of cancer
As well as lowering the risk of liver cancer, consuming coffee has been linked to a reduced risk of several other types of cancer.
A study that looked at the coffee drinking habits of 447.000 people over 10 years found those who drank at least 4 cups of coffee a day had a 20% lower risk of developing melanoma.
It is also linked to a reduced risk of endometrial cancer, one of the most common gynecologic malignancies in the United States. Other studies have found that adults who drink four or more cups of coffee a day are half as likely to die of oral cancer.
8. Lower the risk of stroke
Several studies carried out in the U.S. and Sweden found that older women who drank more than one cup of caffeinated coffee per day had a 20% lower risk of stroke. Another Swedish study carried out in 2008 found similar results in older men.
9. Boost concentration and memory
Although it’s widely accepted that caffeine does have some cognitive-enhancing effects, it has been difficult to pinpoint the exact ways it affects concentration and memory.
However, researchers at the Johns Hopkins University found that coffee enhances certain memories up to 24 hours after being consumed, and that is has a positive effect on long-term memory.
According to Walter Willet, M.D. at the Harvard School of Public Health, coffee is a “potent collection of biologically active compounds”. As caffeine is absorbed into the body it passes into the brain quickly, and triggers the body to release adrenaline to make us feel more alert.
Caffeine or Decaf?
You might be surprised to hear that decaf coffee isn’t totally free of caffeine, as only 97% is removed. So if you were to drink 10 cups of decaf coffee in a day, this would be equivalent to one or two cups of regular coffee.
People often wonder whether decaffeinated coffee offers the same health benefits as regular coffee, and the answer is a little complex. First, It’s important to be aware of the methods used to remove caffeine from coffee beans, as using “methylene chloride” could increase the risk of cancer. Removal with water is considered the safest method.
It appears decaf can increase blood cholesterol levels and contribute to heart disease, so it may counteract the positive effects that coffee has on cardiovascular health. Decaf coffee doesn’t seem to offer the same protection against Type 2 diabetes either, as it doesn’t decrease C-peptide levels as effectively.
As caffeinated coffee can exacerbate certain conditions such as heartburn, acid reflux, and insomnia, people often switch to decaf instead. Unfortunately, this doesn’t always provide a good solution.
As coffee is highly acidic, it can easily irritate the gastrointestinal tract. It seems that decaf can increase stomach acid even more than regular coffee, so switching to caffeine-free won’t help if you suffer from heartburn.
For many, that first cup of coffee in the morning wakes us up and gives us a boost to start the day. However, it’s easy to end up in a vicious cycle if you suffer from insomnia. If you’ve slept badly and increase your coffee intake the next day, you may sleep badly again.
If you think caffeine is keeping you awake, it’s better to switch to decaf after noon or avoid coffee altogether.
Drinking coffee can relax the sphincter muscle that stops stomach acid traveling back up the esophagus, so many people find it worsens acid reflux symptoms. In this case, decaf coffee seems to have less effect on this muscle, and therefore produces less of a reflux effect.
Finding the Right Balance
It’s important to remember that studies surrounding the benefits of coffee tend to focus on black coffee. Many drinks available from large coffee chains often have a high content of fat and sugar, which are known to be harmful to our health.
For instance, compare the calorie content of a plain cup of brewed coffee (2 calories, no fat, and no carbs) to a Starbucks White Chocolate Mocha (580 calories, 15 grams of saturated fat, and a whopping 75 grams of sugar!).
If you consume a large amount on a daily basis but aren’t a fan of black coffee, it’s best to use low-calorie, low-fat add-ins such as skimmed milk or almond milk.
It’s also important not to substitute coffee for other healthy behaviours such as going for a walk or enjoying a nutrient-rich diet. A brief amount of exercise can be as good as a cup of coffee for an afternoon pick-me-up, and has other cardiovascular benefits too.
Most research suggests that drinking 3 to 5 cups a day is the most beneficial for your health, but that doesn’t necessarily mean you should increase your coffee intake if you’re happy with 1 or 2 cups.
Avoid giving caffeine to children
Although it was once thought that caffeine could stunt kids’ growth, there does not appear to be any scientific evidence to suggest this is the case. That said, there are plenty of reasons you should avoid giving coffee or other caffeinated beverages to children.
As a stimulant which affects the nervous system, coffee produces similar effects in children as it does in adults. Therefore, it could cause insomnia, headaches, nervousness, and dizziness.
A 2014 study which appeared in the journal Pediatrics found that the amount of caffeine present in one cup of coffee was enough to increase children’s blood pressure. They also noted a slower heart rate to compensate for the rise.
Coffee is an incredibly complex seed which has over 1.000 different compounds. More and more research is focusing on the health benefits which drinking coffee seems to offer, although it’s not clear exactly how each compound affects our body.
It is generally agreed that 3 to 5 cups of black coffee a day can help reduce the risk of Type 2 diabetes, protect against cardiovascular disease, slow the progress of dementia, and reduce the risk of certain types of cancer.
But people react to coffee in different ways. Whilst some people can drink 10 cups a day and feel fine, others begin to feel jittery, nervous, and have problems sleeping. So it’s important to drink a moderate amount which suits you best.
One of the biggest questions seems to be whether drinking decaf produces the same beneficial effects as regular coffee. Although more research is needed on the subject, in most cases decaffeinated coffee doesn’t produce the same benefits.
Checkout my guide on commercial coffee machines.