Scientists find caffeine in 100% of donor blood samples – and 70% contained anti-anxiety drug Xanax

Scientists find most US donated blood is contaminated with caffeine and Xanax

  • Oregon State University researchers were testing the purity of donor blood for an upcoming study
  • They found 100% of the 18 batches they received contained caffeine
  • 72% contained Xanax, and 44% contained traces of a cough medicine
  • The team was forced to enlist their own volunteers to abstain from caffeine and medications to donate blood for their research

Stress levels are at a record high in the US – and it shows.  

In a recent study by Oregon State University, researchers found caffeine in 100 percent of blood samples that were destined for blood transfusions, and traces of Xanax, an anti-anxiety medication, in 72 percent.

The team studied 18 batches of pure human blood serum that had been donated to blood banks, but were passed to biomedical suppliers as they neared their expiration date. 

Many samples contained traces of cough medicine. 

The researchers warn their study shows a high risk for contamination of blood used for transfusions.  

Americans’ love of coffee was borne out in a new study by Oregon scientists who found caffeine in all of the blood samples they tested, while eight contained dextromethorphan, an over-the-counter cough suppressant, and 13 contained Xanax

‘From a “contamination” standpoint, caffeine is not a big worry for patients, though it may be a commentary on current society,’ said Chen, a PhD student.  

(Indeed, a recent study found 64 percent of Americans drink at least one cup of coffee a day.)

‘But,’ Chen added, ‘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.’

Chen and co-author Richard van Breemen, the director of OSU’s Linus Pauling Institute, did not set out to see test caffeine levels in blood. 

Originally, they set out to test a new way of screening drug interactions in the blood system. 

They planned to gather a group of study participants, and get them to take a drug cocktail along with a supplement, such as licorice or hops, to see if the herb made them metabolize the drugs differently – a pressing question as more and more Americans take supplements for various health complaints.

‘Botanicals basically contain natural products with drug-like activities,’ van Breemen said. 

‘Just as a drug may alter the drug-metabolizing enzymes, so can natural products. 

‘It can become a real problem when someone takes a botanical supplement and is also on prescription drugs – how do those two interact? 

‘It’s not straightforward or necessarily predictable, thus the need for methods to look for these interactions. 

‘The odd thing in this case was finding all the tainted blood.’ 

Their study, partly funded by the National Institutes of Health, was thrown off course when they found that the controls – supposedly ‘pure’ samples of blood from blood banks – were already riddled with other substances. 

All of the samples contained caffeine, eight contained dextromethorphan, an over-the-counter cough suppressant, and 13 contained Xanax.   

‘The study leads you in that direction, though without doing a comprehensive survey of vendors and blood banks we can only speculate on how widespread the problem is,’ said van Breemen. 

‘Another thing to consider is that we found drugs that we just happened to be looking for in doing the drug interaction assay validation – how many others are in there too that we weren’t looking for?’

The study was published in the Journal of Pharmaceutical and Biomedical Analysis, and they were also able to complete the research they’d set out to conduct. 

To do so, they had to contract two donors who agreed to abstain from caffeinated foods and drinks.