Many people who consume caffeine do so through coffee.
The latest research says for most adults, up to five, 8-ounce cups of caffeinated coffee per day (or 400 mg of caffeine) is safe and appears linked to a lower risk of cardiovascular disease for some individuals. A 2022 study put the limit at 3-and-a-half cups.
Dr. Sreenivas Gudimetla, a cardiologist with Texas Health Fort Worth, explains to KERA's Sam Baker what might account for the change.
Dr. Gudimetla: There's what's called a J-curve hypothesis, meaning you don't get the benefit from coffee unless you consume moderate amounts of coffee. Moderate amounts of coffee seems to be sort of that sweet spot right now.
Baker: So up to five cups of coffee then shouldn't hurt you.
Dr. Gudimetla: You want to do it in the morning hours, don't drink coffee as much in the afternoon or at night because it disrupts your circadian rhythms and therefore it will also alter your sleep pattern. You won't get enough sleep at night and we know that cardiovascular health benefits are seen with good sleep.
Baker: Does everyone react to caffeine the same way?
Dr. Gudimetla: No, there is a lot of variation in each individuals and you know, they are identifying specific genetic factors which affects some people more than others. And there are different variations in the genetic sequence where some people have a greater benefit from coffee versus some people who don't.
As well as of course you have social and cultural factors. And also other behaviors such as exercise and heart healthy behaviors, or for that matter, other medications that can affect the variance of coffee consumption in different people.
And so it is not the same for everybody.
Baker: The study seems to be talking about black coffee consumption, but does it get more dangerous when you're going, let's say, in latte territory?
Dr. Gudimetla: You actually cancel out the benefits. Adding sugar, flavored syrups, additional dairy products could increase your caloric intake and therefore counteract the potential health benefits associated with coffee itself.
Baker: Benefits from coffee?
Dr. Gudimetla: I think the strongest association with coffee is that it does actually decrease the risk of type 2 diabetes mellitus. The effects on development or progression of coronary artery disease, there may be a slight benefit or it may be neutral. And I think that the same applies to risk of heart failure. There is a lower risk of a stroke with coffee consumption. It does potentially reduce the risk of atrial fibrillation.
The other thing I want to point out with unfiltered coffees in general, there is a substance called cafestol, which actually increases the LDL or bad cholesterol. That's the one sort of adverse effect of coffee, but everything else seems to be either neutral or somewhat positive.
Baker: Anything else you'd like to add?
Dr. Gudimetla: The one thing I always like to remind people of is drinking coffee is not the sort of holy grail. I think it's something that can potentially help, but we all have to keep in mind healthy lifestyle: exercise on a regular basis, eat a heart healthy diet, don't partake in other risks such as smoking, drugs or heavy alcohol abuse.
I think every aspect of that is very important in terms of heart health and they've done studies looking at what are the factors that affect one's overall survival and number one on the list - and this actually exceeds genetics, even - is healthy lifestyle.
Baker: Maintaining that and guidelines here in the study on coffee and caffeine should be okay?
Dr. Gudimetla: It should be okay, absolutely.
Copyright 2026 KERA News
