There’s been so much conflicting information about coffee over the years that it’s enough to give even the most resilient among us some serious trust issues. Some say coffee is a cancer-fighting superfood, others say it’s an addictive concoction that will do nothing but dehydrate you, stunt your growth, and in the long run, kill you.
If you’re anything like me, all this information has given you a love-hate relationship with your morning elixir. Regardless of which side of the fence you’re on when it comes to coffee, though, you probably still find yourself craving a cup of it every now and again. So, for the coffee junkies, occasional sippers, and emergency-all-nighter-essay-writing drinkers alike, we’ve tackled the most popular coffee rumours to discern fact vs fiction when it comes to this morning routine staple.
Ah, one of the oldest tales told about coffee, but is there any truth to it?
It’s hard to pinpoint exactly where this misconception came from, but smear advertising by coffee competitors likely had something to do with it. The early 20th century coffee alternative Potsum, for instance, spent a great deal of time and money decrying the supposedly damaging effects of coffee on children’s growth and learning abilities. Even though this negative advertising successfully changed the American attitude towards coffee, there is actually no scientific evidence to support the old wives’ tale that coffee stunts your growth.
Still, some might try to argue that coffee disrupts physical growth because of its propensity to cause osteoporosis. Fortunately for coffee-lovers like myself, the scientific evidence is clear – coffee definitely does not cause osteoporosis. Though some studies have shown that caffeine could lead to a small decrease in calcium absorption (which is necessary for bone growth), it is nowhere near enough to cause serious bone density issues in young and healthy people. The amount of calcium excreted due to caffeine is so minimal, in fact, that it can be offset by adding as little as one tablespoon of milk to your cup of coffee. It’s also worth noting that osteoporosis doesn’t technically stunt growth – it puts you at risk for small spinal fractures, and you’d have to go a very long time without any treatment to lose a considerable amount of height this way. So even if coffee did cause osteoporosis, it likely wouldn’t lead to a serious decrease in height.
In short (pun totally intended), coffee will definitely not relegate you to a life of not being able to reach the top shelf.
Caffeine is a diuretic (meaning it causes you to pee a lot), and since coffee has lots of caffeine, it must cause your body to eliminate a lot of water and put you at risk for dehydration, right? Well, not exactly.
While it’s true that coffee is a mild diuretic, there is no evidence to suggest that it increases the risk of dehydration. This is because coffee does not make you eliminate more liquid than you’ve ingested – after all, coffee is over 98% water, so any fluid going out is being replaced by the fluid coming in. One recent study from the University of Birmingham even found that in caffeine-habituated individuals, moderate coffee intake (around 4 cups per day) is just as good a source of hydration as water, and counts towards daily fluid requirements.
Sorry to disappoint, but the answer to this one is a resounding no.
When caffeine and alcohol are consumed together, evidence from lab experiments suggests that alcohol inhibits caffeine-induced anxiety, but coffee fails to reduce the adverse effects that alcohol has on learning and coordination. So no, coffee does not sober you up – and while its stimulating effect does counteract the sedative properties of alcohol, this may actually be harmful insofar as it gives people the illusion that they are less drunk than they really are, potentially causing them to feel they are sober enough to manage dangerous tasks such as driving.
The answer to this one is a bit complicated.
While a pathological and obsessive form of caffeine consumption has never been observed in humans, it has been well established that regular caffeine intake can result in a mild physical dependence. Symptoms of caffeine withdrawal can include headache, fatigue, drowsiness, irritability, nausea, and anxiety. In the event that you’re a regular coffee drinker looking to kick the habit, you can reduce potential withdrawal symptoms by weaning off of coffee instead of quitting cold turkey.
The question of whether or not coffee is carcinogenic has been a topic of scholarly debate for decades, but a recent Meta-analysis involving over 500 publications from multiple countries has helped put this lingering rumour to rest. The results indicate an overall lack of effect, and for certain cancers, coffee actually seems to have a protective effect.
Specifically, no connection was found between coffee consumption and the development of breast, pancreatic, kidney, ovarian, prostate, or gastric cancer, while a strong protective link was found for endometrial and liver cancers. There did appear to be a risk associated with heavy coffee consumption in certain populations and in men, but for typical 1-3 cups-per-day drinkers, this shouldn’t be a concern.
To reflect the most recent research, as of 2016, the World Health Organization no longer classifies coffee as a possible carcinogen.
As is the case with anything, too much coffee can be bad for you. Everybody is different, of course, and some may be more prone to the anxiety and jitters that can occur with caffeine, but there are some general guidelines to follow; according to the Mayo clinic, adults should limit themselves to about 400mg of caffeine per day, which is equivalent to about four cups of coffee, while adolescents should stick to around 100mg per day.
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