The Science of Coffee Rings

Coffee rings are a little bit ubiquitous in quirky office focused design. Because they’re the kind of mess that hard workers make. But have you ever stopped to wonder why coffee spillages on paper look the way they do? No? Well. That’s why exists. To answer unasked questions about coffee.

So here you go. This was apparently quite a difficult problem to solve.

“It’s taken physicists more than a decade to figure out why this effect, known technically as “the coffee ring effect,” happens. But now they think they have an answer.”

The answer, according to ten years of scientific study, is that coffee particles are spherical (there’s more info, and a video of what is going on at a microscopic level, at NPR).

The study, at first unrelated to coffee, noticed that when liquids with spherical particles evaporated they formed a ring that looked like a coffee ring. Other shaped particles didn’t.

So, thinking they’d solved the coffee conundrum they put it to the test:

“We went down to the building coffee machine, put 35 cents in, got a cup of coffee, went back upstairs to the microscope, put it on a slide, took a look, and, at least on the micron scale, the particles that we saw were spherical in shape.”

So there you go.

10 ways science proves drinking coffee is good for your health

Science. It’s a wonderful thing. And if there’s one thing we’ve learned from the cigarette lobby – it’s that you can use “science” as a tool for anything. Tobacco is definitely harmful. But many people have been told, for many years, that caffeine is almost as bad for you. But it’s not. Though you can take these results, like a bitter cup of coffee, with a grain of salt.

What we’re really looking at here is the health benefits of caffeine consumption. Coffee itself has many psychological benefits. Because it tastes nice, and is a pleasurable experience. But we’ll largely ignore those. You might have been told by all sorts of killjoys, and naysayers, that caffeine is bad for you. Well here’s the almost irrefutable proof that it isn’t. So tell them where to stick their cup of bad advice (see the bonus item on the list) while you enjoy your next cup of caffeinated goodness.

Image Credit: Flickr

1. Caffeine is good for your heart.

In a study published this week in the American Journal of Cardiology an Israeli medical team have discovered that caffeine (three coffees a day worth) is good for the heart. It stops heart attacks and strokes.

“The study found that caffeine consumption improves the functioning of the endothelium by 30 percent, reduces by 40 percent the C-reactive (CRP ) protein in the body , a leading predictor of heart attacks and stroke, and increases by 25 percent the amount of adiponectin, a protein which prevents heart attacks and strokes.”

This study is not an isolated case – it follows a string of recent studies that have downplayed previously held convictions about coffee being bad for one’s heart. An American study of almost 60,000 Finns aged 25-74, published in January 2011, found that caffeine consumption didn’t increase the risk of heart failure. And a German study from April 2010 found drinking between four and eight cups of coffee a day improved one’s cholesterol.

2. Caffeine is good for your head.

The effects of caffeine on the brain are well documented. And we’ll get to the issues of memory and Alzheimer’s in a minute. But it seems caffeine consumption will also help prevent the development of nasty head cancers. Scientists found that five or more cups a day can significantly reduce your chances of developing a nasty head/spine tumour called glioma, at least according to a combined study between researchers from Harvard and the Imperial College, London from January 2010, which found tea and coffee can reduce the risk of developing the cancerous tumours.

“Caffeine has different effects on the brain, some which could play a role in brain carcinogenesis, and coffee has been consistently associated with reduced risk of liver cancer, thus suggesting a potential anticarcinogenic effect. A total of 335 incident cases of gliomas (men = 133, women = 202) were available from three independent cohort studies. Dietary intake was assessed by food-frequency questionnaires obtained at baseline and during follow-up.”

“Consumption of five or more cups of coffee and tea a day compared to no consumption was associated with a decrease risk of glioma (RR = 0.60; 95% CI: 0.41–0.87; p-trend = 0.04).”

Caffeine will also significantly lower the potential development of Parkinson’s Disease, see this study relating to Alzheimer’s that references the Parkinson’s/caffeine relationship, and this abstract for another study.

3. Caffeine is good for your memory.

Caffeine can help your memory if you’ve got a normal, fully functioning, brain. And it’ll also, apparently, stave off the onset of Alzheimer’s Disease. This edition of the Journal of Alzheimer’s Disease is available in full on the web, and is devoted to the relationship between caffeine and the brain. This Science Daily article offers a summary of the findings in that journal.

This study of the available scientific literature found that caffeine is good for the normal function of your memory – but mainly if you’re tired. And because it’s a stimulant. It isn’t hugely beneficial in that sense. But it’ll help if you’re not alert. Here’s a quote:

Caffeine does not usually affect performance inlearning and memory tasks. Occasionally, caffeine effects on memory and learning, facilitatory or inhibitory, were found. These effects were rather the result of complex interactions with dose, subject, and task variables. They may result from effects on encoding, or attention devoted to the information, rather than being direct and specific effects on the storage or retrieval ofinformation in short-term and working memory. Caffeine can apparently improve performance directly over a wide variety of mental tasks, and indirectly by reducing decrements in performance under suboptimal alertness conditions. The efficacy of caffeine under states of reduced alertness is quite consistent.

Translation: Caffeine will help your brain function when it’s tired.
caffeine curve
Image Credit: Flickr

Better news, if you’re trying to justify your coffee habit, is the research into degenerative brain disorders. Another article from the same journal quoted above came up with a slightly different finding.

“Thus, caffeine restores memory performance in sleep-deprived or aged human individuals, a finding replicated in rodent animal models. Likewise, in animal models of Alzheimer’s disease (AD), caffeine alleviates memory dysfunction, which is in accordance with the tentativeinverse correlation between caffeine intake and the incidence of AD in different (but not all) cohorts. Caffeine also affords beneficial effects in animal models of conditions expected to impair memory performance such as Parkinson’s disease, chronic stress, type 2 diabetes, attention deficit and hyperactivity disorder, early life convulsions, or alcohol-induced amnesia. Thus, caffeine should not be viewed as a cognitive enhancer but instead as a cognitive normalizer.”

Again, the take home message seems to be coffee will bring you back to normal from an abnormal spot. Which is a good thing. Better to be normal than sub-normal. This actually meshes nicely with another study into the stimulating effect of caffeine, which found that after an initial high when you first start drinking coffee, your morning coffee returns you to a functional baseline (ie treats withdrawals) rather than actually perking you up.

Although, yet another article from that journal waxes lyrical about the benefits of caffeine consumption. It deals more specifically with caffeine’s effect on synaptic plasticity.

“The cognitive enhancing properties of caffeine have long been recognized, and are experienced daily by regular coffee drinkers. Although it has been more difficult to demonstrate these cognitive enhancing effects in a formal experimental setting, caffeine improves mood and enhances psychomotor and cognitive performance in healthy volunteers, particularly on tasks measuring typing speed, simple reaction time, sustained attention,memory, and logical reasoning, as well as simulated driving.”

Need for Speed anybody? But the best news on the Alzheimer’s Disease front is that aged, Alzheimer’s effected mice that drink caffeine regularly show marked improvement in memory, while mice that grew up drinking caffeine were “protected against memory impairment”… prompting this statement (in this article):

“These results indicate a surprising ability of moderate caffeine intake (the human equivalent of 500 mg caffeine or 5 cups of coffee per day) to protect against or treat AD in a mouse model for the disease and a therapeutic potential for caffeine against AD in humans”

Here’s another article that looks at caffeine and dementia. Again. Finding that caffeine protects your brain. So it’s good for your head. Ok. Onto the next bit of the body.

4. Coffee is good for your throat

Did you know that drinking coffee, at least if you’re Japanese, seems to reduce the risk that you’ll develop cancer in the throat area.

“We conclude that coffee consumption is related to a lower risk of oral, pharyngeal, and esophageal cancers in the general population of Japan. Although cessation of alcohol consumption and cigarette smoking is currently the best known way to help reduce the risk of developing these cancers, coffee could be a preventive factor in both low-risk and high-risk populations.”


5. Caffeine is good for your energy levels.

Everybody knows this. Olympic athletes aren’t allowed to have too much caffeine in their blood, and a whole industry exists to pump youngsters full of the stuff. The bad news is that the best results, performance wise, come when you consume pure caffeine, not coffee.

6. Caffeine is good for your gall bladder.

From what I can tell, this one is a little in dispute. But a study published in the Journal of the American Medical Association in 1999 found that caffeine is an effective prevention method for gallstones. And who wants those.

“During 404,166 person-years of follow-up, 1081 subjects reported symptomatic gallstone disease, of whom 885 required cholecystectomy. After adjusting for other known or suspected risk factors, compared with men who did not consume regular coffee in 1986 and 1990, the adjusted relative risk (RR) for those who consistently drank 2 to 3 cups of regular coffee per day was 0.60 (95% confidence interval [CI], 0.42-0.86) and for those who drank 4 or more cups per day the RR was 0.55 (95% CI, 0.33-0.92). All coffee brewing methods showed a decreased risk.”

7. Caffeine is good for your lungs.

Well. Especially if you have asthma. According to a couple of studies anyway. The first one found that caffeine improves lung function in asthmatics.

“Seven trials involving a total of 75 people with mild to moderate asthma were included. The studies were all of cross-over design. Six trials involving 55 people showed that in comparison with placebo, caffeine, even at a ‘low dose’ (< 5mg/kg body weight), appears to improve lung function for up to two hours after consumption.”

The second, that caffeine acts as an asthma preventer.

“Subjects who drank coffee on a regular basis had a 29% reduction in the odds of having current asthma symptoms (odds ratio, 0.71; 95% confidence interval, 0.55 to 0.93) when compared with non-coffee drinkers. The effect exhibited a significant dose-response relationship, with the number of cups of coffee consumed per day being inversely related to asthma prevalence. This relationship was independent of age, gender, and cigarette smoking.”

8. Caffeine is good for your pain.

This is true in a couple of ways. Firstly. Caffeine helps post exercise recovery. So says a study by University of Georgia researcher Victor Maridakis (see this abstract for the paper published in the Journal of Pain).

“One and two days after an exercise session that caused moderate muscle soreness, the volunteers took either caffeine or a placebo and performed two different quadriceps (thigh) exercises, one designed to produce a maximal force, the other designed to generate a sub-maximal force. Those that consumed caffeine one-hour before the maximum force test had a 48 percent reduction in pain compared to the placebo group, while those that took caffeine before the sub-maximal test reported a 26 percent reduction in pain.”

This confirmed the findings of an earlier study, published in the same journal. Which found that when a bunch of teenage males were asked to engage in a spot of cycling the post-exercise pain was reduced when treated with caffeine.

“Leg muscle pain ratings were significantly and moderately reduced after a high dose of caffeine. This observation suggests that prior reports showing caffeine improves endurance exercise performance might be partially explained by caffeine’s hypoalgesic properties. It also suggests that moderate intensity cycling exercise has promise as a useful experimental model for the study of naturally occurring muscle pain.”

Another study found that caffeine and ibuprofen are the best combined treatment for headaches. And not just caffeine withdrawal headaches. Tension headaches as well.

“Ibuprofen and caffeine administered together provided significantly greater analgesic activity than ibuprofen alone, caffeine alone, and placebo. Ibuprofen and caffeine administered together demonstrated significantly shorter times to meaningful improvement in headache relief than ibuprofen or placebo; significantly greater total analgesia than ibuprofen alone, caffeine alone, or placebo; and significantly greater peak relief than ibuprofen alone, caffeine alone, or placebo.”

Sounds good to me.

9. Caffeine is good for your liver.

A study found that coffee – not just caffeine – has a positive impact on the health of your liver. Especially in the prevention of cirrhosis. So if you’re an alcoholic – it pays to have a simultaneous coffee addiction.

And. Another study found that drinking 2-3 cups of coffee a day will significantly reduce the chances you have of developing liver cancer. And that can only be good news.

“Four cohort and 5 case-control studies, involving 2260 cases and 239,146 noncases, met the inclusion criteria. All studies observed an inverse relation between coffee consumption and risk of liver cancer, and in 6 studies the association was statistically significant. Overall, an increase in consumption of 2 cups of coffee per day was associated with a 43% reduced risk of liver cancer (RR, 0.57; 95% CI, 0.49-0.67). “

10. Caffeine is good for baldness.

Well. Not that sort of baldness.

This one’s a stretch. There other benefits for caffeine consumption that may deserve to make the list. But. Seriously. If you rub caffeine into your scalp you may be able to prevent baldness. And that can only be a good thing. Especially if you look over your shoulder at your father and grandfather at family portrait time and think there’s no hope for you…

Here’s the abstract for the study. We’re talking about people suffering from Androgenetic Alopecia (AGA), which is the fancy name for run of the mill male pattern baldness.

Androgen-dependent growth inhibition of ex vivo hair follicles from patients suffering from AGA was present in the human hair organ culture model, a constellation which may serve for future studies to screen new substances against androgen-dependent hair loss. Caffeine was identified as a stimulator of human hair growth in vitro; a fact which may have important clinical impact in the management of AGA.

Some of the reports I read suggested for best results the caffeine needs to be massaged into the scalp. And the good news is that you can buy some caffeine shampoo.

Bonus: Decaff is good for your colon.

An Oxford study found that decaff, quite appropriately, is only really good for looking after your rear.

“Consumption of caffeinated coffee, tea with caffeine, or caffeine was not associated with incidence of colon of rectal cancer, whereas regular consumption of decaffeinated coffee was associated with a reduced incidence of rectal cancer.”

Summing up

Coffee is good for you. Don’t let anybody tell you otherwise. And here’s a pretty good little visual reminder of where coffee sits on the calorie scale too, in case you need any ammunition to throw back at your critics.

Caffeine vs Calories
Image Credit: Flickr

Science says: Don’t freeze your coffee

Serious Eats is your favourite food blog. You just may not know it yet. They conducted a blind taste test (with the help of my food hero J. Kenji Lopez-Alt.


The table was littered with tiny paper cups numbered one through eight, each representing a different method for storing coffee beans:

  • 1. Whole beans stored at room temperature in a Ziploc bag (Ziploc bags are not hermetically sealed—air can still escape and enter the bag)
  • 2. Whole beans stored at room temperature in a one-way valve bag (from which CO2 can escape but stale-making air can’t get in)
  • 3 and 4. The same beans stored in the freezer
  • 4, 5, 6, and 7. Ground coffee stored in the same 4 manners

The grinds and whole beans all came from the same batch. The coffee was stored for two weeks before we cracked it out, to get the full effect.

The taste test followed an earlier, less scientific, test, which came up with the following conclusion (which I agree entirely with)…

“Looking at the results with an open and caffeinated mind, my recommendation is to treat fresh-roasted coffee just as you would fresh-baked bread: Better to buy a little bit, use it up while it’s fresh, and buy more when needed. And, just as with fresh-baked bread, the second-best—though by a mile—option is to prepare it into individual servings and store them air-tight in the freezer (in the case of bread, that means slices; for coffee, that means premeasured doses you’d use to make a certain size batch of joe at a time), using only what you need at any time and never letting them thaw and refreeze.”

When beans thaw they sweat and their chemical make-up changes. It’s bad. Mmmkay.

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