In this first Summer Series, we’d like to demystify some of the latest, scientific findings on coffee! And hopefully, do our part to clarify and counteract all the misinformation that’s so easily found in our online feeds these days! Below, an amazing scientific review by our own medical expert - Jolian Rios, MD, ABIM Board Certified.
Myth #1: All Studies are Scientifically Valid
Coffee has been widely studied - there have been hundreds of studies published about it over the years. Yet, the first thing to keep in mind is that not all studies are created equal - as they can go from very strict, scientifically valid Cohort, Case-Control, and Randomized Controlled Trials where data drives the findings, to an Opinion Paper, which is simply someone sharing their thoughts - of course, their findings do not carry the same weight! To make matters worse, these Opinion Papers are many times “interpreted” and reported by the media in ways that favor their ratings. So every time you read something, go to the source, and please don’t share it if it is not a scientific source! - advice that seems especially relevant right now!
Myth #2: Coffee = Caffeine
When we think of coffee, we immediately think about caffeine; yet we should keep in mind coffee contains many other compounds with potential health benefits. These include polyphenols such as caffeic acid, chlorogenic acid, diterpenoids, and other antioxidants, as well as potassium, magnesium, niacin, and lignans. In fact, concentrations of these phenolic antioxidants are much higher in brewed coffee than in brewed tea - which is often touted as an antioxidant powerhouse!
Myth #3: Caffeine is Unhealthy
Caffeine is quickly absorbed in the gastrointestinal tract, and it gets metabolized by the liver. It antagonizes adenosine receptors in the central and peripheral nervous systems - and in this way, it can have a variety of effects. Some of the main effects found so far:
Caffeine is a proven analgesic, property that has been used for the treatment of headaches, specifically tension and migraine headaches.
Multiple cohort studies with over 600,000 individuals found it may reduce stroke risk.
Two case-controlled studies and two cohort studies have shown a small protective effect of coffee consumption advanced Alzheimer’s disease. Moreover, animal models have shown long-term caffeine consumption may delay or reduce the risk of Alzheimer's disease.
Randomized Controlled Trials of healthy individuals have found caffeine improves cognition, mood, vigilance, and reaction time - regardless of age and gender.
A study with sleep-deprived Navy SEAL trainees showed improvement of cognitive function, learning, memory, and mood despite continuous exposure to stressors with an optimal dose of 200 mg of caffeine (about two cups of coffee!).
Myth #4: Coffee is Unhealthy
Numerous studies on coffee have actually shown the opposite - there are several health benefits from long-term coffee consumption. Some examples:
A matched case-control of almost 1700 women with BRCA gene mutation found that coffee intake was associated with 10% - 69% lower risk of breast cancer, this was a dose-dependent effect, with the lowest effect being seen on women who drank 1-3 cups of coffee and the largest effect seen on those who drank more than 6 cups of coffee per day.
A case-control study of 1900 women found that coffee intake was associated with a 40% lower risk of breast cancer in premenopausal women who drank 4 or more cups of coffee per day.
A meta-analysis of cohort and case-control studies showed a decreased risk of endometrial cancer in coffee drinkers.
A large prospective analysis of over 47,000 men found a strong dose-dependent reduction in the risk of prostate cancer.
Several studies, including randomized trials, and cohort studies, have shown that coffee consumption, including decaf, decreases the risk of type 2 diabetes, by improving insulin sensitivity as well as insulin secretion.
Another study showed caffeine in coffee to be a potent stimulator of smooth muscles that prevent constipation.
A meta-analysis of 14 different studies shows that coffee drinkers had 39% less probability of developing cirrhosis.
Thus, coffee has been shown to have positive effects on multiple systems and may even lower the risk of multiple chronic diseases in the long term. I’ve listed the studies used for reference, in case you’d like to read in a lot more detail on your own (it pairs perfectly with a great cup of Ethos to keep you awake!).
So, let’s keep enjoying coffee, and let’s continue to make a difference, to Brew Greatness in the world!
References available online at havenmagazines.com
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17. Baker JA, Beehler GP, Sawant AC, Jayaprakash V, McCann SE, Moysich KB. Consumption of coffee, but not black tea, is associated with decreased risk of premenopausal breast cancer. J Nutr. 2006;136(1):166-171. doi:10.1093/jn/136.1.166
18. Bravi F, Scotti L, Bosetti C, et al. Coffee drinking and endometrial cancer risk: a metaanalysis of observational studies. Am J Obstet Gynecol. 2009;200(2):130-135. doi:10.1016/j.ajog.2008.10.032
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25. Murakami K, Okubo H, Sasaki S. Dietary intake in relation to self-reported constipation among Japanese women aged 18-20 years. Eur J Clin Nutr. 2006;60(5):650-657. doi:10.1038/sj.ejcn.1602365
26. Liu F, Wang X, Wu G, et al. Coffee Consumption Decreases Risks for Hepatic Fibrosis and Cirrhosis: A Meta-Analysis. PLoS One. 2015;10(11):e0142457. Published 2015 Nov 10. doi:10.1371/journal.pone.0142457