Blood Donor Caffeine Levels May Affect RBC Storage, Transfusion Effectiveness

Elevated caffeine levels in donated blood may be linked to increased hemolysis and lower post-transfusion hemoglobin increments, according to a study published Sept. 4 in Haematologica. The findings suggest the potential for a more individualized approach to transfusion that considers not only blood type, but also lifestyle and genetic factors that influence RBC quality.

Using data from more than 13,000 donors in the REDS RBC-Omics study, researchers led by the University of Colorado Anschutz Medical Campus found that higher caffeine levels  — the equivalent of consuming 2-3 cups of coffee or espresso prior to donation — were associated with disrupted RBC metabolism and greater markers of oxidative stress and osmotic fragility. These effects were especially pronounced in recipients who received blood from donors carrying common variants in the ADORA2b gene, which regulates RBC function under low-oxygen conditions.

According to Angelo D’Alessandro, PhD, the study’s senior author, the findings identify caffeine consumption as a modifiable factor that influences RBC storage and transfusion outcomes.

“We’ve long understood caffeine’s effects on the brain and central nervous system, but this is the first large-scale study to demonstrate its impact on RBC biology,” D’Alessandro said. “These findings suggest that something as common as your morning cup of coffee could have important implications for the quality of stored blood and how well it works when transfused into patients.”

He suggested that because caffeine has a short half-life, limiting intake around the time of donation could reduce its impact, an approach already reflected in donor guidelines in several European countries, but not in the United States.

AABB Foundation Alumni at the Center of Discovery

D’Alessandro, along with co-investigators Michael P. Busch, MD, PhD, and James C. Zimring, MD, PhD, are each previous recipients of AABB Foundation early-career scientific research grants and members of the AABB Foundation Hall of Fame.

Since 1983, more than 200 researchers have advanced innovative research with funding support from an AABB Foundation grant, a milestone for many investigators that often marks the beginning of their career trajectories. To learn more about these grants or to make a financial gift that supports critical early-stage research and the future leaders of the field, visit aabb.org/foundation.