Coffee is a daily ritual for millions, but does it actually benefit your heart health?
Dr. Gregory Marcus, a UCSF Health cardiologist, has been diving into the research around this connection. On this week's episode of "As Prescribed" with KCBS Radio's Patti Reising, he shed light on what we know -- and what we still don't -- about coffee and the heart.
So, what does the evidence say? As it turns out, the relationship between coffee and cardiovascular health isn't straightforward.
"There is a lot of variability between people," Dr. Marcus explained. "We are all born with different genetic variants that influence how fast we metabolize caffeine. So between two different people drinking the same exact amount of coffee, one may feel the caffeine a lot more than the other."
Regular coffee drinkers also develop a higher tolerance to caffeine over time.
"If you drink more on a regular basis, you're going to ramp up those enzymes that break it down and therefore tolerate more," said Dr. Marcus. That means the impact of coffee on heart health could differ depending on how much coffee someone regularly consumes.
With research suggesting both positive and neutral effects, the true impact of coffee on cardiovascular health remains a topic of debate. Many studies track people's coffee consumption and health outcomes over time, but they rely on self-reported data.
"The problem is that there are other factors, like lifestyle or socioeconomic status, that might influence the outcomes," said Dr. Marcus. For example, people who drink more coffee may also engage in other heart-healthy behaviors, such as exercising or eating better, which could influence the results.
Despite these challenges, the majority of studies indicate that coffee has no harmful effect on heart health or may even offer benefits.
"The very good news is that the great majority of evidence suggests that drinking coffee may either reduce the risks of multiple cardiovascular diseases or has no adverse effect," Dr. Marcus said.
"There's very little evidence to suggest coffee negatively impacts heart health," he added. "We have no evidence to suggest you should avoid it."
Caffeine vs. Decaffeinated Coffee: Does It Matter?
While most studies focus on caffeinated coffee, decaf may still offer potential benefits.
"There are a couple of studies that have suggested benefit to the cardiovascular system among people who consume decaffeinated coffee, suggesting that it's something about the coffee itself, even independent of the caffeine that may be beneficial," said Dr. Marcus. "The exact ingredients there or the exact mechanisms are not fully understood, but are thought to be related to anti-inflammatory effects."
On the other hand, caffeine may have a different effect, as research suggests it can boost physical activity levels.
"We did a randomized control trial where we fit people with a bunch of sensors... and then those participants were randomly assigned from one day to the next, go ahead and drink all the coffee you want today versus avoid all caffeine today," Dr. Marcus explained. "We found on the days when they were randomly assigned to consume coffee, they were much more physically active. Now, the flip side is, as one might expect, they also slept substantially less."
Given the mixed evidence, you may want to weigh the pros and cons of drinking coffee to improve your heart health, with Dr. Marcus cautioning that it's not a one-size-fits-all remedy.
"The way that I interpret the current data is that it's insufficient to recommend either initiating or increasing how much coffee is consumed," he said. "If you enjoy consuming coffee, and you yourself have not experienced a clear adverse effect, then it's fine to continue."
“As Prescribed” is sponsored by UCSF.