How to Drink Coffee for Heart Health (Backed by Science)

What if I told you coffee was good for your heart? Indeed, coffee isn’t just keeping you alive during Zoom meetings—it might actually be keeping you alive. If you like coffee, this is a MUST-read.

What if I told you coffee was good for your heart?

Indeed, coffee isn’t just keeping you alive during Zoom meetings—it might actually be keeping you alive.

In this letter, I’ll break down two human trials, one remarkable mouse study, the key molecule behind coffee’s heart benefits, how to dose and time your coffee for maximum impact, and what I enjoy even more than coffee these days.

First, let’s establish that there is a well-known association between coffee intake and reduced risk of cardiovascular disease—at least up to a point. But large-scale epidemiological studies provide limited insight on cause-effect relationships or mechanisms.

So, we turn to controlled trials and animal studies. In what’s to come, I want to review two human randomized controlled trials, and one fascinating animal study centered around a special chemical in coffee that is responsible for many of its health effects: chlorogenic acid.

If you follow me, you may recall chlorogenic acid from our discussions on how to stop sugar cravings or how the heart talks to the brain. Briefly, it’s a well-studied polyphenolic compound enriched in coffee—especially lighter roasts, unroasted ‘green’ coffee, and Yerba Mate.

Human Randomized Controlled Trials

Let’s discuss two human randomized controlled trials. Both studies aimed to assess the effect of coffee and/or chlorogenic acid on vascular function.

They measured vascular function using flow-mediated dilation (FMD), which evaluates the ability of the endothelium (the inner lining of blood vessels) to dilate in response to increased blood flow. It's a way to assess the health of blood vessels.

In one study, they gave participants one of two different coffees differing in chlorogenic acid content (89 mg or 310 mg), or a placebo control, and then measured FMD. As compared to the placebo, both coffees improved FMD, with the higher dose (310 mg) of chlorogenic acid appearing to have a larger effect.

Testing Isolated Chlorogenic Acid

To further prove it was the chlorogenic acid improving vascular function, they conducted another experiment in which they provided isolated chlorogenic acid rather than coffee. Again, the chlorogenic acid improved FMD.

Results Replicated: Decaf Coffee Improves FMD

These findings have been independently replicated. In another double-blinded randomized controlled trial, decaffeinated unroasted ‘green’ coffee containing chlorogenic acid at three different doses (302 mg, 604 mg, 906 mg) was compared to a placebo control for its effects on FMD. The chlorogenic acid significantly improved FMD versus placebo, although the higher doses did not provide additional benefit.

Quick Summary: These randomized trials suggest that chlorogenic acid in coffee improves vascular function in humans.

But What About Long-Term Heart Health?

Now, that’s interesting—and perhaps sufficient to justify your coffee habits. However, when it comes to long-term health, what you really want to know is whether chlorogenic acid could slow the progression of atherosclerosis, the buildup of plaque in your arteries.

Here, we can’t conduct human controlled trials because atherosclerosis takes too long to develop. Instead, we turn to animal models.

In what may be my favorite coffee-relevant paper to date, researchers gave ApoE^-/- mice (predisposed to atherosclerosis) a control diet vs 200 mg/kg chlorogenic acid vs 400 mg/kg chlorogenic acid vs a statin (4 mg/kg atorvastatin).

Strikingly, chlorogenic acid reduced the progression of atherosclerosis at both doses, with the higher dose having the same effect size as the statin. You can see this clearly in the images on the left showing part of the heart with plaques circled, and in the bar graph on the right showing atherosclerotic plaque area.

That’s like cutting plaque in arteries by half—imagine traffic on a four-lane highway suddenly flowing like it’s a Sunday morning.

How Does It Work?

In follow-up experiments, the researchers found that chlorogenic acid:

1. Reduced levels of inflammatory cytokines

2. Inhibited the formation of foam cells

3. Improved cholesterol efflux

Let’s break these down!

In the rest of this letter, we discuss:

• Nuances of how chlorogenic acid can fight atherosclerosis

• The optimal dosing, and timing, of coffee (based on 2025 data)

• The caffeinated trend that I (reluctantly) adopted

*Nick Note: I’m extremely competitive! Just ask my mother, who does a happy dance any time I lose a board game (rarely). Anyway, after a 3 day streak at #1 on rising science, we’ve been dethroned to #2! Nooo! Let’s back on top and you’ll be rewarded! (That’s a bribe to comment and share. Plus, I love your thoughts!)