​Caffeine is the world’s most widely consumed legal psychoactive substance. As well as being used to avoid fatigue, it has been investigated for its potential antioxidant activity that could lead to protection against diseases such as Alzheimer’s. Despite its widespread use, the exact mechanism of caffeine is not well understood. This study, published in Journal of Applied Physics, used quasi-elastic neutron scattering on the Iris instrument to investigate the interaction between caffeine and a model lipid membrane. 

The lipid used was dioctadecyldimethyl-ammonium bromide, known as DODAB, which forms a structure in solution that is analogous to biological membranes. Depending on the molecular arrangements of the lipids within the membrane, it can form a crystalline or fluid phase. The influence of the caffeine was found to be different for each of these two phases. 

​In the fluid phase, the addition of caffeine restricted the movement of the lipid molecules, whereas the opposite was true in the crystalline phase. These changes to membrane dynamics can impact the fluidity and permeability of the whole membrane, which could affect the functionality of embedded membrane proteins and transport properties of the cell membrane and could be the key to understanding the science behind the boost you get from your morning coffee.  

Related publication: “Caffeine modulates the dynamics of DODAB membranes: Role of the physical state of the bilayer.” Journal of Applied Physics, 128, 154701 (2020) 

DOI: 10.1063/5.0027953​