As pumpkin spice latte season arrives, researchers warn ‘extremely hot’ drinks can cause health problems

Pumpkin spice latte season is back, bringing autumn menus filled with warm drinks. Coffee shops are serving seasonal drinks, while tea and coffee remain everyday favorites for millions. But new research suggests that how hot those drinks are when you drink them may matter for long-term health.

A study published Sept. 8 in the International Journal of Cancer found that people who preferred very hot tea or coffee had a substantially higher risk of developing esophageal squamous cell carcinoma (ESCC). The researchers analyzed data from nearly one million adults in the United Kingdom. They followed participants for roughly 11 to 14 years, depending on the study group.

The researchers found that participants who reported drinking beverages at a “very hot” temperature had about three times the risk. That’s compared with those who preferred warm drinks instead. The association remained after researchers accounted for how frequently participants drank hot beverages.

The study showed that daily quantity also mattered.

The study also found an association with drinking large quantities of hot beverages. People who reported consuming six or more hot drinks per day had a 71% higher risk of esophageal squamous cell carcinoma than those who drank fewer than six, after accounting for beverage temperature.

The findings did not show the same relationship for esophageal adenocarcinoma, another major form of esophageal cancer. Researchers found little evidence that either beverage temperature or frequency was associated with that cancer subtype.

The researchers said the findings support the possibility that repeated thermal injury to the esophagus contributes to cancer development. They also found that the association was similar for people who primarily drank tea and those who primarily drank coffee, suggesting that temperature may matter more than the particular beverage.

So, how hot is too hot?

Researchers did not measure the actual temperature of the drinks participants consumed. Instead, participants described their preferred temperature as “warm,” “hot,” or “very hot.”

The study’s “very hot” category does not necessarily correspond to the temperature of every commercially served hot latte. Researchers based the category on participants’ descriptions of their preferred beverage temperature instead of measuring the drinks themselves.

The researchers noted that previous studies suggest tea and coffee in the United States and the United Kingdom are commonly consumed at about 60 degrees Celsius, or 140 degrees Fahrenheit. They also said their results suggest increased risk may occur at temperatures below the 65 C threshold used by the International Agency for Research on Cancer (IARC).

IARC classifies beverages consumed above 65 C, or 149 F, as “probably carcinogenic to humans.” But IARC also cautions that 65 C is a practical classification threshold, not a precise biological cutoff that tells people exactly how much heat causes cancer.

Starbucks’ publicly available beverage materials provide some context for the findings. A Starbucks beverage manual says steamed milk should reach 150°F to 170°F, with 130°F as the standard for children’s beverages. That range includes temperatures above the 149°F threshold the International Agency for Research on Cancer uses to define “very hot” beverages.

However, the new study did not measure the actual temperature of participants’ drinks. It does not establish that a Starbucks latte served within that range carries a particular cancer risk.

Although a threefold increase sounds alarming, the absolute risk for ESCC remains low for non-smokers and non-heavy drinkers in Western countries, where tobacco and alcohol remain the primary drivers. Furthermore, because this was an observational study based on self-reported beverage temperatures rather than direct physical measurements, the findings demonstrate a strong statistical correlation rather than definitive direct causation.

In other cancer news, researchers have linked an alarming rise in colon cancer cases in young people to a bacterium in the gut.

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