Coffee is one of the world’s most commonly consumed beverages. The coffee culture is an undeniable feature of modern living, but over the years science has presented mixed messages regarding its benefits.
Recent research published in the British Medical Journal suggests that three to four cups of coffee a day is linked to longer life expectancy (except during pregnancy and for women at risk of fracture).
The study examined existing evidence for associations between coffee consumption and multiple health outcomes. It gave an umbrella review of evidence across meta-analyses of more than 200 observational and intervention studies. Overall the authors claim drinking coffee is likely to benefit wellbeing for a range of health outcomes.
Coffee drinking was linked with a lower risk of several cancers including prostate, endometrium, skin and liver as well as type 2 diabetes, gallstones and gout. The greatest relationship appeared to be seen in chronic liver conditions such as cirrhosis and there are promising associations between coffee consumption and a lowered risk of Parkinson’s, Alzheimer’s and depression.
Positive vs negative
There is a long list of pros for drinking coffee; it is a rich source of antioxidants, has been found to reduce gut permeability, improve mood, enhance memory and boost sports performance. However there can also be some cons; due to caffeine’s mode of action, it can create dependency, raise blood pressure and induce anxiety in susceptible individuals. Therefore it’s reassuring to read research of this kind that invites us to adopt a ‘common-sense’ approach to our coffee consumption.
Coffee is not for everyone and, like any dietary choice, it is always a case of ‘horses for courses.’ If you like coffee, of course you can continue to enjoy it as part of a healthy diet. If you really crave coffee, can’t get through the day without it or you experience anxiety, tremors or gastrointestinal distress then perhaps you should lower the strength of your morning coffee or choose decaffeinated varieties.
Bioactivity of coffee
Many will not be surprised by these findings. Roasted coffee is a complex mix of 1,000 bioactive compounds with potentially therapeutic, anti-inflammatory, anti-fibrotic, and anti-cancer effects. Caffeine is a powerful antioxidant but has also been shown to have “antifibrotic effects by preventing hepatic stellate cell adhesion and activation.” Other compounds such as Diterpines, cafestol and kahweol “induce enzymes involved in carcinogen detoxification and stimulation of intracellular antioxidant defence.”
Genotypes and microbiomes
To complicate matters even further it has been found that an individual’s genotype and gut microbiome determines the bio-availability of coffee metabolites to which that individual is exposed. Therefore, the benefits of coffee drinking are all down to the individual. This might explain why some people are full of energy after a morning latte while others are able to enjoy a double espresso right before bed.
What does this mean for coffee lovers?
Coffee drinking is controversial among health care professionals with some in favour and others strongly against it but I am all about the science. In many ways we should be cautious about making firm conclusions about cause and effect based on this research because the studies included were mainly observational.
For the majority we can assume drinking coffee is safe within the usual patterns of consumption. There also appears to be sufficient evidence in the British Medical Journal’s study to highlight the benefits of drinking decaffeinated coffee. It is positively associated with type 2 diabetes, endometrial cancer and lung cancer. Moreover there were no convincing harmful associations between decaffeinated coffee and any health outcome.
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