Numerous publications and online sources suggest caffeine intake can lead to skin dehydration and should be avoided for people prone to various inflammatory skin diseases. You can see this recommendation not only for seborrheic dermatitis, but also for eczema, psoriasis, rosacea, acne, and many others.
In short: There isn’t enough evidence to suggest that caffeine worsens seborrheic dermatitis symptoms. Excessive consumption could result in increased skin dryness, but consuming enough water throughout the day counters this effect. Plus, there appear to be some proposed benefits of caffeine on overall skin health.
Why does caffeine get so much blame?
The primary argument is that caffeine acts as a diuretic – meaning that it promotes the production of urine. And promoting urine production, caffeine will lead to overall dehydration, which in turn means that your skin barrier weakens and your skin condition is likely to worsen.
However, despite the number of times this argument pops up, there appears to be a general lack of references as to the actual data behind the argument.
Examining the evidence linking caffeine to skin hydration
Since the argument that blames caffeine appears so often, my initial expectation was that there would be many studies that demonstrate the connection. Yet, attempts at finding evidence to support this popular belief were not very productive.
The few papers that I did manage to dig up seemed to show the intake of caffeine-rich beverages have very minimal impact on hydration levels. For example:
- Caffeine intake of up to 400mg per day (equating to roughly 8 cups of tea or 4 cups of coffee) did not lead to dehydration even when exercise was brought into the mix (assumed to magnify the potential effect) 
Digging further, was able to finally find a paper from the Journal of Korean Biological Nursing Science that did seem to suggest that caffeine intake influences skin hydration:
- A significant negative correlation between caffeinated beverages and skin hydration 
But unfortunately, the content of the paper is in Korean and translating it via Google Translate was not very effective. Nonetheless, the data tables were all labeled in English and from here, we see that as long as pure water made up the majority of fluid intake, skin hydration appears to have been maintained even with moderate caffeine consumption.
What this means for seborrheic dermatitis
Now, we know that seborrheic dermatitis is usually accompanied by severely disrupted skin barrier function and an increased level of transepidermal water loss (a fancy way of saying water escaping the body through the skin) [3, 4]. While improving these parameters, generally improves dermatitis .
From this, we see how that common “caffeine is bad for seborrheic dermatitis” theory may have come to be.
Yet, if we consider that the evidence, the impact of caffeine on skin hydration suggests only a small effect and only in the absence of adequate water consumption. So, as long as we consume enough water, it’s unlikely that caffeine will make seborrheic dermatitis symptoms much worse.
Potential benefits of caffeine on skin health and seborrheic dermatitis symptoms
While looking for research on the effect of caffeine on skin health, some additional papers that showed benefits caught my attention. Specifically, it was interesting to learn that:
- Intake of caffeine-rich beverages may have a protective effect on the risk of non‑melanoma skin cancer 
Topical application may be useful for the treatment of premature balding 
Caffeine can have a positive impact on various aspects of skin inflammation and has shown some potential in small scale studies for the treatment of atopic dermatitis (more commonly known as eczema) 
Specifically for males, topical application was demonstrated to improve skin barrier function 
Taken together, it seems that instead of the “simple caffeine is not good for your skin”, there are several potential benefits of caffeine for your skin instead.
Can we trust anecdotal evidence
In addition to the medical literature, there is also a bunch of online chatter with people claiming that once they stopped drinking coffee or tea their skin issues improved. But can we make a general assumption from the suggestions and insights from these sorts of comments? How do we know that the person didn’t jump to conclusions and post their insights, while shortly discovering their resolution was linked to something else entirely?
The simple truth is that it’s generally a good idea to not take anecdotal evidence as hard facts. Instead, it should only be used as a starting point for further inquiry.
I’ve fallen into this trap on far too many occasions while dealing with seborrheic dermatitis. As the condition ravages your social self-esteem, it’s easy to get sucked into the search for that golden key that will solve your issues and let you get back to normal. Maybe this is it, maybe the research just hasn’t considered this connection yet and this amazing tip I just found online is my answer… This is a dangerous road to travel.
In any case, if you think that caffeine may be having an impact on your seborrheic dermatitis, why not conduct a simple experiment:
- Purchase a decaf version of your favorite caffeine-rich beverage
- Stagger your consumption (number of days decaf only, other days the real thing)
- Note down your symptoms each day
Now if you do this long enough (4-6 weeks), you should have your answer as to whether caffeine is having any effect on your seborrheic dermatitis. Plus, if you want to take things further, have someone else prepare you the beverage without revealing which version you receive (granted, would need this information when analyzing your findings, so they would need to keep a record).
While the effect of caffeine on seborrheic dermatitis is not clear and there aren’t any studies that specifically evaluate the correlation between consumption and symptom severity, the surrounding research seems to suggest the negative effect is likely to be insignificant.
So, if you love to regularly indulge in your favorite cup of coffee and/or tea, there doesn’t seem to be any good reason you should give it up at this point. As long as you drink enough water and cut the sugar, your skin is not likely to suffer.