Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes
BMJ 2017; 359 doi: https://doi.org/10.1136/bmj.j5024 (Published 22 November 2017) Cite this as: BMJ 2017;359:j5024
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This scientific paper elicited eleven responses. This is number 12.
Surely Dr Poole and co-authors could respond to us?
Perhaps the bmj editors could remind Dr Poole?
Thank you
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I am surprised to NOT read anything about coffee being an INHIBITOR OF SIRT1. 2 cups a day will STOP production of SIRT 1 &2...Is this too new of a discovery to be mentioned in these articles? .
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Coffee con caveats
Drinking coffee in moderate amounts is safe but with a word of caution for women in pregnancy and those at risk of fractures1. Aggravation of some symptoms such as sleeplessness, restlessness and palpitations by drinking coffee may not be just 'physiological' as reported in the paper. Some of these patients may seek medical attention or even medication. Decaffeinated coffee, though less beneficial than regular coffee, may be a better option for such patients, specifically when the symptoms are troublesome.
The other caveat is the thermal damage to oesophageal mucosa caused by drinking very hot coffee. In the long term, this may increase the risk of malignancy2. It would be safer to let the very hot coffee cool down a bit before drinking.
References:
1. BMJ 2017;359:j5024
2. Islami F, Boffeta P, Ren J et al. High temperature beverages and foods and oesophageal cancer risk - A systemic review. Int J Cancer 2009; 125(3):491-524. DOI: 10.1002/ijc.24445.
Competing interests: No competing interests
Prof Koh has moved, thank goodness, to actually “quantifying” the amount of coffee it is safe to drink..unfortunately, he too is vague.
1. Three to five cups. What size cups are we talking about? Even Turkish coffee cups may hold three ounces or (the larger ones) six ounces.
A cappucino is traditionally, about six ounces.
2. Would you treat (to coffee) an 80 kg man exactly as you would a 60 kg man?
3. Do you see no difference between the consumption of Turkish coffee and, say, cappuccino? Or, Irish coffee?
Just because Christmas is round the corner, you cannot dismiss factors such as the chemical composition, the method of preparation, the amount consumed, the bulk of the consumer. Et cetera. Et cetera.
Umbrella Reviews are shot full of holes. Meta analyses of, say, Physalis edulis consumers are simpler - only two varieties. Meta analyses of the taste of baked apples are extremely difficult - Bramleys, Jonagolds, Lord Derbys are very different.
Competing interests: No competing interests
Poole R, et al1 evaluated the existing evidence for associations between coffee consumption and multiple health outcomes by performing an umbrella review of the evidence across meta-analyses of observational and interventional studies. The umbrella review identified 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with nine unique outcomes. Coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures including high versus low, any versus none, and one extra cup a day. There was evidence of a non-linear association between consumption and some outcomes, with summary estimates indicating largest relative risk reduction at intakes of three to four cups a day versus none, including all cause mortality, cardiovascular mortality, and cardiovascular disease. High versus low consumption was associated with an 18% lower risk of incident cancer. Coffee drinking seems safe within usual patterns of consumption, except during pregnancy and in women at increased risk of fracture.
Korea is the second most frequently consumed country worldwide. Many Korean patients with cardiovascular diseases would like to enjoy drinking coffee, however most do not because of incorrect knowledge. Previous studies already reported similar results. Indeed, Harvard group tried to elucidate considerable controversy on the association between coffee consumption and cardiovascular disease (CVD) risk by performing a meta-analysis with thirty-six studies including 1 279 804 participants and 36 352 CVD cases. A nonlinear relationship of coffee consumption with CVD risk was identified. The study demonstrated that a nonlinear association between coffee consumption and CVD risk was observed and moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups per day, and heavy coffee consumption was not associated with elevated CVD risk.2
This group also investigated an inverse association of caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes by performing a systematic review and a dose-response meta-analysis. They observed that coffee consumption was inversely associated with the risk of type 2 diabetes in a dose-response manner. Both caffeinated and decaffeinated coffee was associated with reduced diabetes risk.3
In summary, moderate coffee intake can be part of a healthy diet.4 However, should doctors recommend drinking coffee to prevent disease? Should people start drinking coffee for health reasons? Guallar answered “no” to both questions in his editorial.5 The evidence is so robust and consistent across studies and health outcomes, however, that we can be reassured that drinking coffee is generally safe, although some caveats apply. the amount consumed is important. For many endpoints, the lowest risk of disease is associated with drinking three to five cups of coffee a day. Higher intake may reduce or reverse the potential benefit, and there is substantial uncertainty, both in individual studies and in meta-analyses, about the effects of higher levels of intake. The safety of coffee should thus be restricted to moderate intake, generally considered as ≤400 mg of caffeine a day (about four or five coffee drinks).5
Funding: None, Disclosures: None
REFERENCES
1. Poole R, Kennedy OJ, Roderick P, Fallowfield JA, Hayes PC, Parkes J. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes.
BMJ. 2017;359:j5024.
2. Ding M, Bhupathiraju SN, Satija A, van Dam RM, Hu FB. Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies. Circulation. 2014;129:643-659.
3. Ding M, Bhupathiraju SN, Chen M, van Dam RM, Hu FB. Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis. Diabetes Care. 2014;37:569-86.
4. Guallar E, Blasco-Colmenares E, Arking DE, Zhao D. Moderate coffee intake can be part of a healthy diet. Ann Intern Med. 2017;167:283-284.
5. Guallar E. Coffee gets a clean bill of health. BMJ. 2017;359:j5356.
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Thanks for the cites, George Henderson.
See also;
Salomone, Federico & Galvano, Fabio & Li Volti, Giovanni. (2017). Molecular Bases Underlying the Hepatoprotective Effects of Coffee. Nutrients. 9. 85. 10.3390/nu9010085. PMID 28124992.
We should pursuing treatments with this with rigor.
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If the directionality of the association is in fact that coffee ingestion leads to decreased overall mortality, this intervention would exceed in effectiveness statins and most of our wonderous medications. If this effect could be copyrighted by pharma, the phase III trials and consultancy work for branding would already be hot venture capital investments.
Competing interests: No competing interests
May I first wish you all Merry Christmas
The "umbrella review" must be valuable (to those who market coffee). Its value to most consumers though is doubtful.
It may be health promoting. It may not do any harm to most drinkers (of coffee) - whether strong Turkish, or "Coffee mit schlag", Viennese fashion. Or, any other.
Do you remember the coffee substitutes used in this starved country as a result of WW 2?
Could the epidemiologists mount a comparative trial of the coffee from say, Jamaica, India, Brazil, using different strengths , different methods of roasting...... The permutations are endless.
The research may take three generations. But so what.
Rome was not built in a day.
Admittedly, it took only a few hours for the Polish and allied soldiers to force the Turks to retreat from Vienna. But far more importantly, the Turks left their coffee beans behind. The Viennese coffee shops assured me that their "coffee mit schlag" is better than the Turkish coffee. I accept that.
Also, please may we also include in the trial, Irish Coffee?
Thank you
Competing interests: No competing interests
Coffee maybe, but caffeine? In evolutionary terms caffeine is a neurotoxic insecticide and as our physiology has common routes it would be expected that we would be similarly effected? All the morbidity and mortality cited is physical and no mental health conditions included. Paucity of research into mental health or a bias? Anxiety and insomnia are everyday experiences for some caffeine users and withdrawal headaches and morning apathy without that early caffeine hit reinforcing their dependence a daily spectacle at our miriad of coffee shops on offer.
Competing interests: No competing interests
Re: Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes
Hello,
I have a theory about coffee consumption and it's potential harms/benefits. I think there are 2 kinds of people: there are people who can consume coffee and in whom the coffee is very beneficial, for cognitive function, immunity, etc. And then, there are the people in whom coffee consumption is detrimental. In fact, I am one of these people. Since I stopped drinking coffee, my migraine headaches have almost completely vanished (I used to get them at least once a month and they were devastating). Also, I just feel healthier. There may be a gene that determines whether coffee agrees with one or not. In fact, when I was reading my Child Development textbook, I am pretty sure that they mentioned that some fetuses cannot tolerate coffee consumption by the mother and develop learning disabilities while other fetuses are not so adversely affected. This is why, to me, the studies on coffee are not definitive. There are 2 subpopulations of people in whom coffee reacts quite differently.
Competing interests: No competing interests