There was absolute panic in 1981. Imagine sitting at the table, enjoying your morning cup of coffee, with the day’s paper spread out in front of you. Your eyes fall on a headline in bold, black letters:
“Coffee consumption linked to cancer risk.”
With your cup in one hand, you skim the article. It’s about new research from the prestigious New England Journal of Medicine. The researchers examined 369 patients with pancreatic cancer — one of the most deadly forms, and notably, the same type of cancer that claimed the life of Apple co-founder Steve Jobs. When they compared these patients to individuals who were very similar but didn’t have pancreatic cancer, they found a shocking result [1].
They examined how various lifestyle factors might be associated with higher pancreatic cancer risk. Alcohol? No association. Cigarettes? There was an association, but it was weak [1].
But one association stood out: coffee.
A strong link between coffee consumption and pancreatic cancer was evident in both sexes. Those drinking up to 2 cups per day had an 80% higher risk, and those drinking 3 or more cups had nearly 3 times the risk, compared to non-coffee drinkers [1].
Table of Contents
- A Shocking Cancer Link
- The Bladder Cancer Scare
- Coffee Cleared of Cancer Links
- Heart Health and Coffee
- Cholesterol and Brewing Methods
- Coffee and Cardiovascular Protection
-
Concerns About Heart Rhythms
- Why Coffee Might Be Protective
- Caveats and Limitations
- Final Thoughts
- References
A Shocking Cancer Link
That wasn’t the end of the panic.
In 1991, another cancer concern hit the headlines — this time linking coffee with bladder cancer. The International Agency for Research on Cancer (IARC), part of the World Health Organization, officially classified coffee as “possibly carcinogenic to the human urinary bladder” [2].
Just like smoking, coffee appeared to be dangerous to our health.
But researchers noticed something odd.
Smoking is a well-established risk factor for bladder cancer, and smokers often drank more coffee. So was coffee directly contributing to the cancer, or was it just guilty by association?
The Bladder Cancer Scare
That question led to a tidal wave of research.
By 2016, the IARC revisited the evidence — this time drawing on more than 1,000 studies involving both humans and animals [3]. After a thorough review, they concluded that the previous classification had been mistaken.
The evidence did not support a causal link between coffee and bladder cancer. In fact, there was inadequate evidence to consider coffee carcinogenic at all [3].
Coffee Cleared of Cancer Links
Meanwhile, a significant new study tackled the question of coffee and pancreatic cancer.
This time, researchers followed two massive U.S. cohorts — the Health Professionals Follow-Up Study (1986) and the Nurses' Health Study (1980) — over many years. Participants completed food frequency questionnaires at baseline and during follow-up.
The result? No association between coffee intake and pancreatic cancer risk [4].
In fact, the new data started to point in a totally different direction. Researchers found that higher coffee consumption might actually be protective in the case of certain cancers.
A major IARC review found statistically significant inverse associations between coffee intake and both liver and uterine (endometrial) cancers [5]. One meta-analysis published in 2012 found a 30% lower risk of endometrial cancer among coffee drinkers [5].
Heart Health and Coffee
Even with the cancer concerns now put to rest, doctors still had lingering worries — especially about the heart.
A 2004 review warned that caffeine could raise blood pressure, potentially contributing to 14–20% of premature deaths from heart disease and strokes [6].
At a population level, the blood pressure rise from caffeine might seem small — around 4/2 mmHg — but even modest increases can have a major impact over time [6].
So even if coffee was cleared from a cancer perspective, many doctors still advised patients to cut back for heart health reasons.
Cholesterol and Brewing Methods
There was another concern as well: cholesterol.
Unfiltered coffee has been shown to raise LDL cholesterol, a key factor in heart disease. But filtered coffee? Not a problem.
A meta-analysis confirmed this:
Unfiltered coffee raises LDL, but filtered coffee does not [7].
So brewing method matters. French press, Turkish coffee, and espresso machines without paper filters — these can increase LDL cholesterol. Using a paper filter can eliminate that effect.
Personally, I use filter paper when making my coffee each morning.
Coffee and Cardiovascular Protection
But there’s more. A recent article in the European Heart Journal reviewed all the latest evidence — and what it found was surprising [8].
Let’s start with blood pressure.
Yes, coffee can raise blood pressure immediately — especially in non-habitual coffee drinkers. One study found a 12 mmHg spike after a triple espresso [8].
But here’s the twist: in regular coffee drinkers, that same triple espresso didn’t raise blood pressure at all [8].
Even more fascinating, decaf coffee caused a similar blood pressure rise in non-coffee drinkers. This suggests that the effect may not be due to caffeine at all, but rather other compounds in coffee [8].
So what happens over the long term?
A meta-analysis involving over 200,000 people found that drinking 1–2 cups per day wasn’t associated with an increased risk of high blood pressure [8].
In fact, the opposite was true:
People drinking 3 or more cups per day had a lower risk of developing high blood pressure [8].
So the conventional blood pressure worry? It doesn’t hold up. Doctors had to do another 180° turn.
Concerns About Heart Rhythms
So far, so good. But what about heart rhythm problems?
Because caffeine is a stimulant, doctors were concerned it could worsen arrhythmias like atrial fibrillation (AF).
But again, the latest data surprised everyone.
In a large cohort study of patients already diagnosed with AF, daily coffee drinkers had a 23% lower risk of major cardiovascular events — including stroke, heart attack, or heart-related death [9].
And in a separate randomized clinical trial, patients who had undergone cardioversion for AF were less likely to have another episode if they continued drinking coffee compared to those who abstained [10].
This is completely counterintuitive — and a reminder of why we need to test our assumptions, not just rely on theory.
Why Coffee Might Be Protective
So how can something that raises our heart rate and blood pressure in the short term protect us in the long term?
We don’t fully understand the mechanisms, but here are some strong possibilities:
- Adaptation: Regular coffee drinkers stop experiencing the blood pressure spike — suggesting the body adapts.
-
Complex composition: Coffee contains a blend of compounds with antioxidant, anti-inflammatory, and fat-metabolism-boosting effects [11].
These effects may explain why coffee is associated with a lower risk of:
-
Coronary artery disease [8]
-
Heart failure [8]
- Stroke [8]
- Type 2 diabetes [8]
- Overall mortality [8]
A meta-analysis of 30 cohort studies found that moderate coffee consumption was linked with reduced coronary artery disease risk. Other large studies like the Framingham Heart Study and UK Biobank found no increase — and sometimes a decrease — in heart failure risk.
Coffee consumption has also been linked to reduced stroke risk, even at levels of eight cups per day. And it's associated with lower overall mortality, meaning people who drink coffee tend to live longer [8].
Caveats and Limitations
Before you brew your next pot, here are some important caveats:
1. Moderation is key
Most benefits are seen with 2–4 cups per day. Going beyond that can reduce benefits or even increase risks.
2. Be careful about additives
If you’re loading your coffee with cream and sugar, you may be cancelling out the health benefits [12].
3. Arrhythmias can still be a concern
While recent data is reassuring, people with certain heart rhythm problems should consult their doctor before drinking coffee.
4. Individual variation matters
Some people are more sensitive to caffeine and experience anxiety, poor sleep, or jitters. Pay attention to how your body reacts.
5. Study limitations
Most coffee research is based on observational studies. That means we can’t definitively say that coffee causes better health outcomes. It’s possible that coffee drinkers have other healthy habits that explain the benefits [8].
Studying coffee is also tricky because of the wide variation in:
- Brewing methods
- Caffeine content
- Additives
-
Timing of consumption
And it’s hard to find people willing to go completely without coffee for a long time in randomized trials.
As one review concluded:
“Determination of whether the inverse association between coffee and cardiovascular outcomes is truly causal and identification of the underlying mechanisms mediating this effect remain the goal of future research efforts” [8].
Final Thoughts
Let’s return to the issue that started it all: blood pressure.
As we’ve seen, coffee doesn’t appear to be a major factor, especially for regular drinkers. But blood pressure remains one of the most critical risk factors for heart health.
New blood pressure guidelines have recently been released, and it’s crucial to understand what the latest targets are. Just like with coffee, many people are relying on outdated advice.
References
1. https://www.nejm.org/doi/full/10.1056/NEJM198103123041102
2. https://publications.iarc.who.int/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Coffee-Tea-Mate-Methylxanthines-And-Methylglyoxal-1991
3. https://www.iarc.who.int/wp-content/uploads/2018/07/pr244_E.pdf
4. https://pubmed.ncbi.nlm.nih.gov/11352851/
7. https://pubmed.ncbi.nlm.nih.gov/11207153/
8. https://academic.oup.com/eurheartj/article/46/36/3546/8193215
9. https://link.springer.com/article/10.1186/s12916-024-03817-x
10. https://jamanetwork.com/journals/jama/article-abstract/2841253
11. https://pmc.ncbi.nlm.nih.gov/articles/PMC10769121/
12. https://pubmed.ncbi.nlm.nih.gov/40368300/
