The Impact of Caffeine on the Cardiovascular System

coffee - caffeine impacts heart health

For those of us who love our morning coffee – or our energy drink before heading to the gym – the thought that it could be harming our cardiovascular system is not something we want to consider. But what science and medicine now tell us about caffeine is not all bad, though we do need to monitor our intake.

The US Food and Drug Administration estimates that the average amount of caffeine consumed in the U.S. daily is equal to 2-4 cups of coffee per person.  Many studies indicate that this level of consumption – considered to be moderate – has a variety of health benefits.  But other studies claim that even as little as 1-2 cups of coffee per day or the equivalent, can negatively impact our health.  So, who is right?  And what should we believe?

Let’s look more closely at this ever-popular stimulant and analyze the potential health benefits, as well as the negative side effects, of caffeine consumption.

What Is Caffeine?

Caffeine is a product found naturally in raw coffee beans, cocoa, kola nuts, guarana berries and tea leaves that can diminish feelings of tiredness and improve concentration.  Found in coffee, tea, chocolate, energy drinks, soft drinks and some cold and allergy medicines, its effects start as soon as 15 minutes after it’s consumed and can last up to 6 hours.

The effects can vary greatly person to person based on their lifestyle and their genetics, which may be the reason for the mixed messages surrounding whether it is good for us or bad for us.

Potential Health Benefits of Caffeine

Some studies have shown that a few cups of coffee a day – or the equivalent – can reduce the risk of liver, mouth and throat cancer.  Others studies have documented caffeine’s positive effects on the brain, including a reduction in suicide risk, a boost to long-term memory, and a decreased risk of diseases like Alzheimer’s and Parkinson’s.  Caffeine can also boost sports performance in athletes, particularly in team sports like soccer, football or rugby.

Potential Negative Effects of Caffeine

In contrast to the possible health benefits of caffeine, it does have some negative effects on the cardiovascular system especially when very large amounts of it are consumed daily. Caffeine can raise your heart rate and cause palpitations and extra heartbeats.  And using large amounts of it for long periods can increase your risk of having a heart attack.  This is particularly true in people who have diabetes.

Blood pressure can go up significantly after caffeine use because it seems to block a hormone our bodies produce to keep our arteries open wide.  When caffeine makes the blood vessels in our bodies narrower, this leaves less room for blood flow which, in turn, raises blood pressure.  The blood vessels supplying blood to the brain can also narrow as much as 27% after caffeine intake which can slow down our ability to think and perform mental tasks.

Coffee drinking is also linked to higher levels of cholesterol, especially in people who drink coffee that is processed at very high temperatures like espresso.  And finally, caffeine has been shown to make arteries stiff which contributes to coronary artery disease or hardening of the arteries as we age.


With some information that tells us caffeine has positive effects on our health and other information saying it can harm us, what approach is best?  We recommend that you try to strike a balance.

For most of us, moderate amounts of caffeine can have mostly positive effects.  So, you don’t have to give up your morning coffee, but limit it – or your other sources of caffeine – to the equivalent of 2-3 cups per day.  Of course, lower levels are recommended for pregnant women who are usually advised by their physicians to limit caffeine to 12 ounces of coffee or other caffeinated beverages per day.

If you have diabetes, high blood pressure, high cholesterol or are at risk of other disorders of the cardiovascular system such as coronary artery disease, heart failure, or abnormal heart rhythms, it is best to try to avoid caffeine and substitute non-caffeinated, herbal coffees or teas.

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