A Cup a Day Keeps Cancer Away? Here’s What Science Says

For decades, researchers have searched for a clear answer on whether coffee and tea can help prevent cancer.

New findings suggest these popular drinks may lower the risk for some cancers—but the science is far from settled.

Studies show that coffee consumption is linked to a lower risk of liver, endometrial, and colorectal cancers.

More recently, an analysis of over a dozen studies found that drinking coffee or tea daily was associated with a significantly lower risk of head and neck cancers. Some findings even suggest decaffeinated coffee may provide stronger protection than its caffeinated counterpart.

But before you rush to refill your mug, experts warn that not all the data lines up perfectly.

Researchers studying head and neck cancers found that people who drank four or more cups of caffeinated coffee per day had a lower risk of developing oropharyngeal, hypopharyngeal, and oral cavity cancers.

Decaffeinated coffee was also associated with reduced oral cancer risk, hinting that caffeine may not be the key ingredient behind these effects.

In colorectal cancer research, decaf coffee showed an even stronger protective effect than regular coffee. Scientists believe compounds called polyphenols—naturally occurring antioxidants found in both coffee and tea—may play a larger role than caffeine.

These compounds have been shown to fight oxidative stress and even slow the growth of cancer cells in lab studies.

While this sounds promising, not all the data is consistent. One unexpected finding linked greater tea consumption to an increased risk of laryngeal cancer.

Some researchers suspect that certain bioactive compounds in black tea might relax the esophageal sphincter, increasing acid reflux—a known risk factor for laryngeal cancer.

Scientists emphasize that the relationship between coffee, tea, and cancer is complicated.

What you put in your cup matters just as much as what’s in the drink itself.

Many studies don’t account for how people prepare their coffee or tea. Adding milk, sugar, or flavored syrups could influence results.

The temperature of the drink might also play a role, as scalding hot beverages have been linked to an increased risk of esophageal cancer. Even the country of origin of coffee beans or the type of tea leaves used might impact health outcomes.

Genetics and gut health also influence how individuals metabolize coffee and tea. Some people break down caffeine quickly, while others process it more slowly, which may alter how these beverages affect cancer risk.

So, while coffee and tea may offer some protective effects against certain cancers, experts agree there isn’t enough definitive evidence to make firm dietary recommendations yet.

What’s clear is that these drinks contain powerful antioxidants and bioactive compounds that could benefit health—but they are not a cure-all.

Cancer prevention depends on many factors, including diet, lifestyle, and genetics. If you enjoy coffee or tea, there’s no reason to stop drinking them, but moderation is key.

And if you’re adding heavy creamers, sugar, or artificial flavors, it may cancel out the potential benefits.

More research is needed before doctors can confidently say your morning cup of coffee could help protect against cancer. Until then, it’s just another reason to savor that first sip of the day.

Sipping to your health,

Rachel Mace
Managing Editorial Director, e-Alert
with contributions from the research team

P.S. Can your morning coffee protect against heart disease and diabetes? Find out here.

Sources:

Smith, J. (2025, February 10). Coffee and Tea Linked to Reduced Cancer Risk, But the Cup is Murky. Medscape. https://www.medscape.com/viewarticle/coffee-and-tea-linked-reduced-cancer-risk-cup-murky-2025a10003ca