Science and the medical community tend to have a love/hate relationship with coffee. On one hand, studies show positive benefits to coffee consumption, like prevention of stroke, heart disease, age-related memory loss, and other neurological diseases. And let’s not forget about that much-needed energy boost coffee provides to millions of Americans every morning, thanks to its caffeine content.
On the other hand, coffee has a few negative effects, too — the main one being a temporary increase in blood pressure (due to the caffeine). Coffee also has been shown to potentially increase the risk of osteoporosis.
Despite the pros and cons, one thing’s for sure: Coffee, and our obsession with it, is not going to go away anytime soon. In fact, because coffee is so popular in our society, many researchers are looking for other positive effects it may have on the body, in addition to the confirmed benefits mentioned above. And according to research, another bonus to your coffee habit may just be a decreased risk of heart failure.
In this meta-analysis, researchers examined five studies that looked at the link between coffee consumption and the risk of heart failure. Between the five studies, the number of participants totaled 140,200. Three of the studies consisted of participants with no history of heart attack, while the fourth consisted of individuals with a history of heart attacks, and the final study included people with and without a history of heart attacks or diabetes.
Researchers found that, compared to not drinking coffee at all, the relative risk of heart failure with regular coffee consumption was:
- 0.96 for 1-2 cups per day
- 0.93 for 2-3 cups per day
- 0.90 for 3-4 cups per day
- 0.89 for 4-5 cups per day
- 0.91 for 5-6 cups per day
- 0.93 for 6-7 cups per day
- 0.95 for 7-8 cups per day
- 0.97 for 8-9 cups per day
- 0.99 for 9-10 cups per day
- 1.01 for 10-11 cups per day
- 1.03 for 11 cups per day
What this means is that there is a “J-shaped” relationship between coffee and risk of heart failure, with the lowest risk of heart failure seen when four daily cups of coffee were consumed. Drinking those four cups translated to an 11% lower risk of heart failure. The risk started slightly increasing again at five cups per day, and continued an upward trend from there on.
The researchers found no evidence that sex or history of heart attacks or diabetes changed these results.
One point to take into account is that researchers did not know if the coffee consumed in all of the studies was caffeinated or decaffeinated. However, all the studies took place in Sweden and Finland, where they say almost all the coffee is caffeinated.
However, they also state that other studies have shown no difference in the risk of high blood pressure between caffeinated and decaffeinated coffee,  and since high blood pressure is a risk factor for heart failure, “it is possible that protection against heart failure would not differ between caffeinated and decaffeinated.”
On that same note, considering high blood pressure is a risk factor for heart failure, and, as mentioned earlier, the caffeine in coffee tends to increase acute blood pressure, how is it that coffee reduces the risk of heart failure?
Well, the jury is still out on this one. But according to one study, habitual coffee drinking can actually cause the body to develop a bit of a tolerance to the acute blood pressure effects of caffeine.
How Much is Really in a Cup?
Think four cups of coffee is a lot to drink for heart-protective benefits? Well, when you think about how much of a super-size nation we live in, it’s really not. Just think about how large a “large” coffee is at most popular chains. And some coffee mugs, quite frankly, look like bowls with a handle.
In fact, the researchers state that, in Sweden, a standard cup of coffee is 150 mL, and in Finland, it’s 100 mL. In the United States, though, a standard cup is quite a bit larger, at 250 mL. So really, the four cups of coffee found to be beneficial in this study is the equivalent of two cups of coffee here in the United States.
With all that said, if you’re a coffee drinker, this study provides yet another reason to savor your cup of joe every morning. But to get the most health benefit, consider stopping after two cups.
 Mostofsky et al. Habitual coffee consumption and risk of heart failure: A dose-responsive meta-analysis. Circ Heart Fail. 2012 Jul;5(4):401–5.
 Winkelmayer WC et al. Habitual caffeine intake and the risk of hypertension in women. JAMA. 2005;294:2330–35.
 Uiterwaal CS et al. Coffee intake and incidence of hypertension. Am J Clin Nutr. 2007;85:718–23.
 Mostofsky et al.
 Riksen NP, Rongen GA and Smits P. Acute and long-term cardiovascular effects of coffee: Implications for coronary heart disease. Pharmacol Ther. 2009;121:185–91.