Far from promoting rosacea, a higher intake of caffeinated coffee is associated with a reduced risk of rosacea, researchers report in an article published online October 17 in JAMA Dermatology.
Caffeine from other sources, such as caffeinated soda, tea, and chocolate appear to have no such protective impact, report Suyun Li, PhD, an epidemiologist at the School of Public Health, Qingdao University, Shandong, China, and colleagues.
The researchers analyzed data from the longitudinal Nurses' Health Study II cohort and found a dose–response association with increasing ingestion of both caffeine generally and coffee specifically, which counters the notion of limiting caffeine intake and coffee consumption to prevent rosacea flares.
The absolute risk of incident rosacea fell by 132 per 100,000 person-years for the highest versus the lowest quintile of caffeine intake and, similarly, by 131 per 100,000 person-years for caffeinated coffee consumption of at least four servings a day versus less than one serving per month. A benefit was not seen with decaffeinated coffee.
The effect translated to a 23% reduction in risk with at least four servings of coffee a day (hazard ratio (HR), 0.77; 95% CI, 0.69 - 0.87; P < .001 for trend). For decaffeinated coffee, the HR was 0.80 but the reduction was not significant (95% CI, 0.56 - 1.14; P = .39 for trend).
The authors note that higher caffeine intake was associated with being a current or past smoker and oral contraceptive user, as well as with somewhat older age and higher alcohol consumption.
"The finding that consuming caffeine from coffee protects from the risk of developing rosacea may have clinical and public health implications and may inform clinical practice to address patients' queries," senior author Wen-Qing Li, PhD, from the Department of Dermatology, Warren Alpert Medical School, Brown University in Providence, Rhode Island, told Medscape Medical News. "Public messages are warranted with regard to the potential protective effect of coffee and caffeine against rosacea development."
In a related editorial, Mackenzie R. Wehner, MD, MPhil, from the University of Pennsylvania in Philadelphia, and colleagues write, "This study provides evidence that patients with rosacea need not avoid coffee, and it offers all of us one more reason to continue drinking coffee regularly."
Li and colleagues analyzed data from 82,737 participants in the Nurses' Health Study II who responded in the 2005 survey to a question on rosacea. There were 4945 incident cases of clinically diagnosed rosacea during 1,120,051 years of follow-up. The mean age at entry of all cohort participants was 50.5 years, whereas the mean age of caffeine consumers across quintiles was about 36 years. Analyses were adjusted for potential confounders such as age, race, body mass index, and lifestyle factors.
According to the authors, caffeine may act through an effect on vascular contractility, with increased intake reducing symptoms by decreasing vasodilation. Caffeine also contains antioxidants and has immunosuppressant effects, which may mitigate inflammation. Caffeine can also modulate levels of hormones such as adrenaline, noradrenaline, and cortisol, which can impact rosacea.
The authors speculate that although other compounds in coffee could lower risk, the lack of effect from decaffeinated coffee undermines that explanation. They suggest that the heat in decaffeinated coffee, which lacks the compensatory protection of caffeine, might counteract the beneficial effect of drinking coffee.
Previous case-control studies and reviews have reported differing effects from caffeine or coffee consumption on rosacea risk. An Estonian case-control study and a literature review from France found no significant difference in risk between groups consuming different amounts of caffeine, while a case-control study from Poland reported an increased risk in coffee drinkers.
The lack of effect from noncoffee sources of caffeine is likely because of the low absolute caffeine content of these foods and beverages, the authors explain. "Further studies are required to explain the mechanisms of action of these associations, to replicate our findings in other populations, and to explore the relationship of caffeine with different rosacea subtypes," they write.
The editorialists point out that the perennial question remains whether it is caffeine, coffee, or a combination of both that is responsible for the protective effect.
The study was supported by a Research Career Development Award of Dermatology Foundation, Richard B. Salomon Faculty Research Award of Brown University, and National Institutes of Health grants for the Nurses' Health Study II. Two coauthors report a variety of ties with one or more of the following: Abbvie, Amgen, Sanofi, Regeneron, RTI Health Solutions, Astellas Canada, Prime Inc, Spire Learning, CME Outfitters, Janssen, Merck, Novartis, Pfizer, and the Eczema Society of Canada. The remaining authors and editorialists have reported no relevant financial relationships.
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Cite this: Coffee May Reduce Rosacea Risk - Medscape - Oct 18, 2018.