Caffeine is an Immunomodulator
Caffeine appears to have an anti-inflammatory effect in some situations and helps calm down an “overactive” immune system. In animal (rodent) models, it’s quite clear that caffeine can affect a variety of different types of inflammation. The effects on humans appear similar, with caffeine having an effect on multiple parts of the immune system - particularly immune cells known as lymphocytes.
To date, there is good evidence to suggest a suppressive effect of caffeine on the proliferation of “stimulated” lymphocytes. In other words, immune cells that have become too active can be quieted down with caffeine. Other immune cells such as natural killer cells and macrophages also exhibited a reduced activity in the presence of high doses of caffeine.
Caffeine may also be truly Immunosuppressive in some situations given the reduced levels of anti-inflammatory cytokines such as TNF-α, IL-2 and IL-6. Moreover, certain receptors, such as TLR1, TLR2, TLR4, and MHC class I-related chain B molecules are also decreased by caffeine.A recent study showed that caffeine inhibits STAT1 signaling and downregulates inflammatory pathways involved in autoimmunity.
In actual human epidemiologic studies, coffee has mixed effects. Caffeine (coffee) consumption appeared to increase the risk of developing type 1 diabetes and rheumatoid arthritis. In contrast, coffee may help somewhat to prevent ulcerative colitis and multiple sclerosis. There does not appear to be an association ether way for other autoimmune diseases such as systemic lupus erythematosus, psoriasis and Crohn's disease.
In the world of hair loss, there are very few studies which have objectively examined the benefits of caffeine. Some studies have suggested a minor benefit for caffeine containing shampoos but these studies are small and have not yet been independently replicated to any significant degree.
It is fascinating to consider that caffeine has the potential to effect so many parts of our immune system. More studies are needed to understand whether or not caffeine can integrate into the treatment of various types of hair loss.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887