We Enjoy Coffee, Tea, and Chocolate So Much that Caffeine is in Donated Blood

We consume so much caffeine from coffee, tea, and chocolate that caffeine was in every "pure" blood sample researchers sourced from biomedical suppliers.
John Loeffler

What can we say? We love caffeine. At least that's what a new study tells us that found traces of caffeine in every sample of "pure" blood it received from a local blood bank.

Caffeine likely permeates our supply of donated blood

It's probably the world's most-consumed drug and it appears to be permeating the supply of donated blood if a new study in the Journal of Pharmaceutical and Biomedical Analysis is correct.


Researchers at Oregon State University (OSU) were conducting mass spectrometry research when they procured 18 samples of "pure" human blood serum from various medical suppliers, sourced from multiple donors. All 18 batches they received tested positive for caffeine.

"From a 'contamination' standpoint, caffeine is not a big worry for patients, though it may be a commentary on current society," said Luying Chen, a Ph.D. student at OSU. "But the other drugs being in there could be an issue for patients, as well as posing a problem for those of us doing this type of research because it's hard to get clean blood samples."

In addition to caffeine, several samples tested positive for alprazolam — often sold under the brand name Xanax — as well as over-the-counter cough suppressant.

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