"Funding<p>This study has been supported by Tchibo GmbH, Hamburg, Germany."<p>Tchibo is a German chain of coffee retailers and cafés known for its range of non-coffee products that change weekly.<p><a href="https://en.wikipedia.org/wiki/Tchibo" rel="nofollow">https://en.wikipedia.org/wiki/Tchibo</a><p>Number of locations
700 shops (Germany)
300 (rest of world)<p>They might want to make some in-store claims about Dark Roast...
If we had even 1 honest meta-analysis for every 10 trials like this, well, we'd know more than we do now. Small trials with inconsistent/poor designs are the bane of medical science.<p>That said, I drink dark roast so this study must be true.
I drink coffee nearly every day; I am reading this in a coffeeshop. But, p = 0.028? Come on. If you tested for a few dozen things, you would expect to find at least one that had a p-value like that. Was this pre-registered to look at only DNA damage, via this metric? Or did they look at 100 different things to find one with p=0.028?<p>Of course, if they pre-registered and their theory was that it would reduce DNA damage as measured in this way, that would be a bit different, but from this article it's hard to say.<p>Now, back to drinking my mocha latte.
I really hate bad science, and this is an example.<p>Springer Science+Business Media (the publisher) does not transfer copyright of the paper from the author to the publisher like many other journals. This begs the question, why isn't this article open access? The primary author, Dorothea Schipp, is a statistics consultant in small town Germany [0] not associated with a University and the blood work was done in Slovakia. No PHDs or MDs among them. [1].<p>Digging deeper into their research method [2] the study looked at DNA breakage over a four month period in blood sampling for a coffee and non-coffee/caffeine group. I have a few questions about this, mainly around how effective the time period and method for determining total DNA stability. How many individual cell gnomes were measured in the before/after? What's the random variance for genome variability among cells in the same body? I suspect the variance is high enough to explain their unbelievably low p.<p>My guess is that the statistician is having fun with p-hacking [3] while collecting some funding from industry.<p>[0] <a href="https://en.wikipedia.org/wiki/Rosenthal-Bielatal" rel="nofollow">https://en.wikipedia.org/wiki/Rosenthal-Bielatal</a><p>[1]<a href="https://link.springer.com/article/10.1007/s00394-018-1863-2" rel="nofollow">https://link.springer.com/article/10.1007/s00394-018-1863-2</a><p>[2] <a href="https://www.mdlinx.com/journal-summaries/coffee-comet-assay-human-intervention-study/2018/11/20/7549520/" rel="nofollow">https://www.mdlinx.com/journal-summaries/coffee-comet-assay-...</a><p>[3] <a href="http://psychology.wikia.com/wiki/P-hacking" rel="nofollow">http://psychology.wikia.com/wiki/P-hacking</a>
Stopped drinking coffee months ago and I have never felt better. Anxiety is down. Sleeplessness is down. General mood is up. Best of all, I no longer get headaches due to Caffeine withdrawal.
Quick googling indicates that tea has similar effect <a href="https://www.ncbi.nlm.nih.gov/pubmed/24585444" rel="nofollow">https://www.ncbi.nlm.nih.gov/pubmed/24585444</a> (very small study but effect size is good), another study is <a href="https://academic.oup.com/jn/article/138/8/1567S/4750818" rel="nofollow">https://academic.oup.com/jn/article/138/8/1567S/4750818</a><p>What are the common ingredients in coffee and tea except caffeine?<p>EDIT:<p>It seems like black tea also, although I can't make sense of the biological jargon. <a href="https://pubs.acs.org/doi/abs/10.1021/jf010875c" rel="nofollow">https://pubs.acs.org/doi/abs/10.1021/jf010875c</a>
To what extent are "DNA strand breaks", as measured in a blood sample, correlated with other health outcomes?<p>Caffeine is a diuretic. The coffee group likely consumed more total liquids in the course of the treatment. So the mechanism might be simply more flushing of damaged cells – possibly beneficial, but not unique to coffee.<p>It's odd for the headline to highlight "dark roast" when lighter roasts weren't tested, for comparison.
I'm surprised (horrified?) that a control group's DNA deteriorates significantly enough in such a short trial to use as a comparison. #entropy
I wonder if they took fast vs slow metabolizers into account. It seems to be healthy only with the fast metabolizers gene:<p><a href="https://drwillcole.com/caffeine-one-thing-standing-optimal-health/" rel="nofollow">https://drwillcole.com/caffeine-one-thing-standing-optimal-h...</a><p>If you’re a slow caffeine metabolizer:<p>1. Increased risk of high blood pressure (hypertension).<p>2. Increased risk of heart attack.<p>3. Higher chance of digestive disorders.<p>4. More stress and measurable cortisol spikes.<p>If you're a fast metobolizer:<p>1. Longer life.<p>2. Faster metabolism.<p>3. Better memory and mood.<p>4. Lower cancer risk.<p>5. Better blood sugar + insulin balance.<p>I'm most assuredly a slow metabolizer since caffeine makes me feel terrible.
Hey guys Pub Med Labs developer here.
Check out this very same fascinating article in the new Labs site and please give us your feedback! Much appreciated.<p><a href="https://www.ncbi.nlm.nih.gov/labs/pubmed/30448878-consumption-of-a-dark-roast-coffee-blend-reduces-dna-damage-in-humans-results-from-a-4-week-randomised-controlled-study/" rel="nofollow">https://www.ncbi.nlm.nih.gov/labs/pubmed/30448878-consumptio...</a>
Garbage!<p>Figure 2: The coffee-treated group is anomalously higher in the quantified metric BEFORE the treatment. This is entirely an artifact of stratifying the treatment vs. control group prior to wash-out. The only significant difference is between all groups and the PRE-treatment coffee group.
While the research may be compromised by a conflict of interest, I still have a legit question.<p>Trader Joe's discontinued my favorite dark roast coffee (Fair Trade Organic Guatemalan) and nothing I've found has come close to the taste and cost.<p><a href="http://www.traderjoesreviews.com/product/trader-joes-fair-trade-organic-guatemalan-coffee-reviews/" rel="nofollow">http://www.traderjoesreviews.com/product/trader-joes-fair-tr...</a><p>Does anyone have a suggestion for me that's ~$10-$12 per pound?
> consumed 500 ml of freshly brewed dark roast coffee blend per day,<p>half a liter per day of coffee is a lot! I wonder if they controlled for caffeine<p>some highlights from my reading:<p>- 372mg caffeine per day<p>- water-only group specifically avoided caffeine<p>- coffee/caffeine group had to abstain from all caffeine for 4 weeks before study (baseline to 300+mg a day is a LOT for someone with no tolerance)<p>- they base their claim of the 'darkness' of the roast mattering on other similar studies, with less pronounced results, that used lighter roasts.<p>"Among several previous studies of the effects of coffee
consumption on DNA damage, only two were randomised
controlled trials, with DNA breakage rather than oxidative
modification of DNA bases analysed [23]. Bakuradze et al.
[14] also studied the effects of coffee C21 consumption, after
4 weeks of intervention, and found a decrease of DNA strand
breaks by 27% in comparison to the control group with water
consumption (p<0.001). Misik et al. [22] studied a much
shorter intervention period (5 days) and a different coffee
type and used isolated lymphocytes. In comparison to C21,
the coffee had an approximately twofold content of caffeoyl
quinic acids and trigonelline and about half of N-methylpyridinium. Therefore, the coffee used by Misik et al. is a light/
medium roast type while we used here a dark roast blend.
We assume that the different degree of roasting accounts
for the different outcome observed. "
The first thing I notice is that both the first and last authors of this paper are industry-affiliated. Not to say there's anything inherently problematic with that, but at least raises an eyebrow about the motivation behind this study.
Too bad dark roast coffee also triggers a bunch of digestive tract ailments. Other than stomach ulcer, hemorrhoids, and all the bowl irritations, dark roast coffee is just fine. Noooooooooooooooot.
I'm willing to bet there is another study that coffee causes some sort of cancer (last I saw it was linked with colon cancer). I'll still drink my coffee, and tea, and probably continue to consume nicotine in one of many forms.<p>Life is too short to worry about maybe, probably is something you should likely worry about - that why I stopped inhaling burning things to feed my nicotine addiction, while cancer isnt all that likely, COPD, heart failure, and others issues sure as hell are.
While I'm always happy to hear good news about coffee (although as an espresso aficionado, I'd be hard pressed to consume half a litre a day), given the obvious difference between coffee and water, I don't see how this can be a 'single-blind' study.
Yeah, this is bullshit.<p>100 people were a part of this "controlled" study.<p>Please don't be one of those people that runs around telling people this. This is nothing more than biased surveying by a weak company in attempt to create self-promoting propaganda.<p>Thank you @1_over_n for doing the research
I grew skeptical the moment I read "single-blind" test. So, the researchers know which group is what and that could involuntarily lead them to pick for what they are leaning to find (given it is funded by a coffee company)
As a stimulant coffee could be placing stress on the body leading cells with damaged DNA to act more aberrantly and subsequenttly rejected by the body.
"The study comprised two periods of 4 weeks: a preconditioning period, with daily consumption of at least 500 ml water but no coffee, nor tea, nor any other caffeine-containing product. During the subsequent intervention period the coffee group consumed 500 ml of freshly brewed dark roast coffee blend per day, the control group consumed water instead."<p>Apparently, it's caffeine, or perhaps hot beverages (as it doesn't seem like the control drank their water heated).<p>The information that would help me is an answer to the question: Why?
Coffee remains one of the few things you can buy the best of, in the world, for less than $100usd and enjoy for several days.<p><a href="http://store.georgehowellcoffee.com/coffees/limited-roasts" rel="nofollow">http://store.georgehowellcoffee.com/coffees/limited-roasts</a><p>Only grind what you are going to brew immediately. Use a conical Burr grinder. Technivorm coffee machine else bonavida.
What about <a href="https://www.reuters.com/article/us-california-lawsuit-coffee/cancer-warnings-to-be-served-up-with-coffee-in-california-idUSKBN1I930H" rel="nofollow">https://www.reuters.com/article/us-california-lawsuit-coffee...</a>
All I can say... "Is Most Published Research Wrong?"
<a href="https://www.youtube.com/watch?v=42QuXLucH3Q" rel="nofollow">https://www.youtube.com/watch?v=42QuXLucH3Q</a><p>TL;DR: Likely yes. Spinning statistics is not that hard, even with the best of intentions.
>Our results indicate that regular consumption of a dark roast coffee blend has a beneficial protective effect on human DNA integrity in both, men and women.<p>What they established was that drinking water damages DNA. When they drank coffee there wasn't as much damage. It's a stretch to say that coffee is providing a protective effect though.<p>Without denigrating anyone, it's a bad study.<p>What was the chemical breakdown of the water? Was it tap water? Distilled? Bottled? Spring? etc.<p>A better designed study would have groups drinking different kinds of water. Was the fact that the water was boiled (in the coffee) providing the protective effect? i.e removing toxins etc, did the kettle they use have a filter that processed the water, whereas the water was drunk straight from a tap etc.<p>Coffee is great though!