Is coffee bad for you?

Coffee has developed the reputation as being the not-so-healthy-for-you cousin to tea. Despite its ability to improve focus, alertness, and possibly even athletic performance, it seems as if everyone is always trying to break up with coffee. Should we all be switching to tea? Is coffee good for us or bad for us? And how much coffee is too much? Let’s break down what the science says about coffee and our heart health

What is in coffee?

Coffee is a brewed plant-based beverage consumed by almost half of all Americans. As you probably know, it’s main active compound is caffeine - usually about 95 mg per 8 ounce cup, but this can vary widely. It also has lots of other chemicals and minerals, such as polyphenols (antioxidants), as well as small amounts of vitamin B, magnesium, and potassium.

And turns out some of these other compounds may be responsible for some of it’s good (and less good) effects on the body.

Does coffee raise blood pressure?

Acutely, for some.

In people who are non-habitual drinkers (ie don’t typically drink coffee), it can raise their blood pressure by as much as 12 mmHg about an hour after consumption. Interesting, decaffeinated coffee may show a similar blood pressure raising effect in non-habitual coffee drinkers, implicating some other compound in coffee other than caffeine (we don’t yet know what). So if you don’t regularly drink coffee, just prior to your doctor’s appointment is not the best time to decide to do so.

For those of us that regularly consume coffee, it doesn’t typically appreciably raise blood pressure acutely.

Additionally, chronic consumption does not appear to be linked to risk of developing hypertension. In the most recent meta-analysis of 15 studies, there was no statistically significant effect of coffee consumption on blood pressure or the risk of hypertension.

Is Coffee Bad for Cholesterol?

It depends on the type of coffee you drink.

Filtered coffee, such as drip coffee in a typical home brewed cup, does not appear to worsen low-density lipoprotein (LDL) cholesterol (or any other lipid measurement).

On the other hand, non-filtered coffee, like in French press, appears do so, and fairly significantly if consumed in larger quantities. This is likely due to coffee lipid compounds, such as cafestol, that are removed by a paper filter. In fact, in one (older) study, daily ingestion of 4-6 cups of non-filtered coffee raised LDL by as much as 15 mg/dL! This was not seen with a similar intake of filtered coffee.

Coffee heart palpitations?

Mechanistic studies in test tubes and animals have demonstrated a theoretical risk of heart rhythm issues or arrhythmias.

However, studies in humans have demonstrated that in amounts we typically consume - up to 400 mg a day, which is about 5 cups of coffee - there is no evidence that coffee causes arrhythmias like atrial fibrillation. (Of note, excessive caffeine consumption -such as that found in energy drinks - has been linked to arrhythmias, but this is a topic for another day.)

That said, some people are more sensitive to caffeine and notice increased palpitations with caffeine intake - those individuals may choose to restrict coffee and other caffeinated beverages to improve their symptoms.

Does coffee cause heart attacks?

No. Moderate intake of coffee, variably defined as <5 or 6 cups of coffee per day, has not been associated with increased risk of heart disease, death from heart disease, stroke, or any other bad heart related outcome.

Some studies even demonstrate a protective effect, particularly as it relates to stroke and death from any cause.

In summary

If you enjoy coffee, don’t feel like you must switch to tea for heart health reasons - unless, of course, it’s keeping you up at night or giving you reflux or palpitations.

If you do decide to drink coffee, limit it to less than 4 or 5 cups a day and choose filtered (aka drip) when possible.

Also, given that sweetened coffee and tea are the fourth largest source of sugar in our diets, it’s much more likely that all of the added stuff is going to be what increases heart disease risk than the coffee itself. So be mindful of what you’re adding in. I’m looking at you Pumpkin Spice Latte.