Coffee seems to be one of those misunderstood foods. One day it’s great for us and the Starbucks sales boom, the next day it’s awful and everyone’s swearing off coffee.
There is some truth to this, so for this week’s WTF Wednesday we’re going to dive into the mixed results from coffee research.
Adults in America drink a whole lot of coffee; it’s the second most consumed beverage (water is #1, hollaaa). Coffee doesn’t just have caffeine, it has hundreds of biologically active compounds and we haven’t even identified all of their functions yet! Due to its popularity, research has been dedicated to exploring the effects of consuming this beverage. Is it good? Is it bad? So far the evidence shows coffee can have a wide range of health effects.
Some potential benefits:
- may lower risk of type II diabetes
- can help with weight loss/management
- reduce depression
- brightens up the morning!
Some potential adverse effects:
- may increase blood cholesterol levels
- increase anxiety
- cause difficulty sleeping
- may even induce heart palpitations
But, overall an emerging body of literature suggests habitual coffee consumption may be neutral to beneficial regarding risk of a variety of adverse cardiovascular outcomes (i.e. Coronary Heart Disease, Congestive Heart Failure, arrhythmias, and stroke).
So what exactly are these bioactive compounds in my coffee? I don’t like the sound of that. I know bioactive sounds scary, but this just means these compounds can have an effect on your body. These compounds include the familiar caffeine, a potent stimulant, diterpene alcohols (like cafestol and kahweol, please don’t ask me to pronounce these because I’m 99.9% sure I do it wrong), which can increase blood cholesterol, and chlorogenic acid, an antioxidant and anti-inflammatory molecule. Coffee also contains vitamins and minerals, like niacin, magnesium, and potassium (we all need more potassium!). Although caffeine is the most widely studied molecule found in coffee, the effects of coffee cannot be reduced to the isolated effects of the caffeine it contains.
Let’s examine some of the findings:
Research has shown coffee (caffeinated and decaf) can lower the risk of type II diabetes by improving insulin signaling.
However, research has also found unfiltered/boiled coffee, like my beloved French-Press coffee, has higher concentrations of diterpene alcohols, which have been shown to increase your blood cholesterol levels by down-regulating bile acid synthesis. This leads to cholesterol not being recycled and made into bile acids, leading to higher levels of cholesterol in your bloodstream. This happens in this type of coffee because the diterpenes are extracted from the coffee beans by the prolonged contact with hot water. If you don’t have high blood cholesterol levels, it’s not enough of an increase to be concerned about and this increase vanishes after a few weeks of not consuming unfiltered/boiled coffee (note: this effect is not seen in brewed/filtered coffee (what most people drink) because of the shorter contact with the hot water and retention of diterpenes by filter paper).
High levels of caffeine (>750 mg/d) may increase urine output and urinary calcium and magnesium excretion.
Coffee intake, at high volumes and in at risk individuals, may be associated with bone loss, lower bone density, or fracture.
This is just the beginning of coffee research. To have a better understanding of the impact of coffee on health outcomes, we need more (and higher quality) clinical data, along with more knowledge about the compounds within coffee.
There still is a lot unknown about coffee, but overall the current research indicates that moderate coffee consumption, typically 2-4 cups per day, fits well with a healthy balanced diet and active lifestyle. The 2015 Dietary Guidelines for Americans included a coffee recommendation for the first time. These guidelines suggest that 3-5 cups of coffee a day is fine if you choose to drink coffee, but don’t pick up a coffee habit because of this!
Keep in mind that there are discrepancies for what constitutes a cup of coffee (in the literature and in real life!). I would recommend sticking with the 8 fl. oz size, which is the amount in a Starbucks short cup. Also, everyone has different caffeine sensitivity levels. I’m super sensitive to caffeine and spent the last 3 years drinking a cup of caffeinated French-Press coffee every morning, but recently switched off the caffeine (maybe I’ll write about this in another post? :)). The good news is that decaf coffee provides these benefits too.
Are you on board with coffee? Why or why not?
What’s your favorite coffee drink? I’m a sucker for lattes!