Coffee is one of those "vices" (like chocolate and wine) that supposedly comes with a slew of health benefits. But when we read stories that say downing six cups per day can lower your risk of type 2 diabetes, we're understandably skeptical. Our BS receptors shot sky high while watching the video "This Is Your Body on Coffee" (check it out below), which claims that drinking four or more cups of coffee per day can improve your overall health.
Yes, the video cites real scientific studies, but before you fill up a celebratory mug, check out these four disclaimers:
1. Studies and recommendations aren't the same thing.
Findings from one-off studies aren't the same as doctors' orders. Even the meta-analysis that looked at 28 studies and found people could drink up to six cups of joe per day without increasing their risk of type 2 diabetes wasn't meant to be prescriptive, says Jessica Yeh, Ph.D., an epidemiology researcher at Johns Hopkins School of Medicine. (Yeh worked on one of the studies included in the meta-analysis. Coffee and sweetened beverage consumption and the risk of type 2 diabetes mellitus: the atherosclerosis risk in communities study. Paynter NP, Yeh HC, Voutilainen S. American journal of epidemiology, 2006, Sep.;164(11):0002-9262.)
“The implication of this study is that if you're drinking a lot of coffee, maybe it's not such a bad thing,” she says. “If you’re not already drinking coffee, there’s no reason for you to start to prevent type 2 diabetes.” Not to mention, many of the studies included in the meta-analysis are based on self-reported coffee drinking, which isn't the most reliable measurement, Yeh says.
2. Gender matters.
We take study findings to be gospel, but they often look at a very specific subset of people. The one that found drinking four cups of coffee before working out increases stamina, for example, was done on eight super-fit male cyclists (a.k.a. not an accurate representation of the everyday Americans).
Similarly, the study that linked drinking coffee with lower risk of depression and the one that found a decreased incidence of skin cancer only included female participants. Increased caffeine intake is associated with reduced risk of basal cell carcinoma of the skin. Song F, Qureshi AA, Han J. Cancer research, 2012, Sep.;72(13):1538-7445.
And we know caffeine can affect men and women differently. “For women especially, caffeine could interrupt your sleep cycle, increase your blood pressure, and lead to anxiety,” says Taz Bhatia, M.D., a women's health and integrative medicine expert.
3. Coffee isn’t the only way to get these benefits.
Some of coffee's key benefits (like improved heart heath and alertness) are thanks to antioxidants. But coffee doesn’t have a magical amount of antioxidants you can’t get elsewhere, says Mark Carter, M.D. “You can get plenty of antioxidants from eating colorful veggies and a varied diet in general,” he says.
This is especially important to consider since coffee comes with obvious drawbacks. “Caffeine is a stimulant, and this may affect sleep/wake cycles and other physiological measures, such as blood pressure and heart rate in the long term,” says Dan Park, M.D., an emergency medicine physician at the Medical University of South Carolina. None of the doctors we spoke with suggested drinking more coffee to just to reap health benefits.
4. If it sounds too good to be true, it probably is.
Most of the studies cited in the video call for drinking more than four cups per day (and some even suggest downing them in under an hour!). “When you drink that much coffee, you’re really ramping up your nervous system,” Carter says. “Eventually, there will be some sort of burnout.”
After you read this article, you’ll probably come across many others debating the benefits and consequences of drinking coffee. If you’re considering drinking more coffee (or dramatically increasing your intake of anything else), start by asking your doc. And remember: Study findings are intended more for the scientific community than for immediate application in our everyday lives.