Study Finds Placebo Effect in Decaf Coffee Drinkers

Research suggests the ritual of drinking coffee may boost energy more than just the caffeine content.

Published on Feb. 15, 2026

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A recent study has found that the act of drinking coffee, even decaf, can provide an energy boost through the placebo effect. Researchers believe the ritual of making, buying, and consuming coffee triggers a psychological response that enhances alertness, separate from the effects of caffeine. The study also found that regular caffeine consumption can lead to increased heart palpitations, though coffee also provides health benefits like antioxidants and nutrients.

Why it matters

This research highlights how much of the perceived energy boost from coffee may be psychological rather than purely physiological. It suggests habitual coffee drinkers could potentially substitute decaf without major changes in their alertness, which could have implications for managing caffeine intake and associated health effects.

The details

The study, conducted in 2025, found that people who drank coffee, even decaf, had increased brain activity and alertness compared to those who took a caffeine supplement. Researchers believe the process of making and consuming coffee triggers a psychological response that enhances the energizing effects, beyond just the caffeine content. A separate 2023 study led by Dr. Gregory Marcus at UCSF found that regular caffeine consumption can lead to an increase in premature ventricular contractions, a type of abnormal heartbeat, even in habitual coffee drinkers.

  • The 2025 study on the placebo effect of decaf coffee was published in February 2026.
  • The 2023 study on the heart effects of caffeine was led by Dr. Gregory Marcus at UCSF.

The players

Maura Fowler

A pediatric and adult dietitian based in Florida.

Gregory Marcus, MD

A cardiologist and electrophysiologist at the University of California San Francisco who led a study on how coffee can affect the heart.

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What they’re saying

“A research study done in 2025 has suggested that the boost in energy that may come from caffeinated coffee may also be related to the ritual of drinking coffee and not just the caffeine content alone.”

— Maura Fowler, Pediatric and Adult Dietitian

“This provides pretty strong evidence that caffeinated coffee really can cause an increase in PVC early beats coming from the lower chamber, even if it doesn't affect the upper chamber heart rhythm issues.”

— Gregory Marcus, MD, Cardiologist and Electrophysiologist

What’s next

Researchers recommend conducting a randomized experiment over several weeks to personally test the placebo effect of decaf coffee versus regular caffeinated coffee.

The takeaway

This research suggests habitual coffee drinkers may be able to substitute decaf without major changes in alertness, due to the psychological effects of the coffee ritual. However, caffeine does have physiological impacts, so moderation is still advised, especially for those with heart conditions or other sensitivities.