Coffee can increase life expectancy, says research institute, but reasons remain unknown

31 Jul 2018 --- Coffee consumption can reduce the risk of death by up to 17 percent, a report on coffee consumption and life expectancy has highlighted. The report is the outcome of a roundtable discussion hosted by The Institute for Scientific Information on Coffee (ISIC) and attended by European researchers, clinicians and dieticians. The roundtable report also considers the implications for healthcare practitioners – for example, should doctors advise patients to drink coffee?

Roundtable speaker Professor Miguel Martínez-González, of the University of Navarra, Spain and Harvard TH Chan School of Public Health, presented unpublished original research studying a cohort of almost 20,000 participants over an average of ten years. Professor Martínez-González’s research suggests that coffee consumption at intakes of 3-6 cups of coffee a day reduces all-cause mortality. Within this cohort, there was a 22 percent lower risk of all-cause mortality for every two additional cups of coffee per day.

Furthermore, the potential mechanisms behind coffee consumption and reduced all-cause mortality were discussed. It was suggested that caffeine alone was unlikely to explain the effect on mortality, mentioning a potential role for polyphenols found in coffee, which may have antioxidant and anti-inflammatory effects.

However, the roundtable concluded that although the link between coffee consumption and reduced all-cause mortality is well documented, the mechanisms remain unknown, and further work is required.

Key research findings highlighted in the roundtable report include:

• Meta-analyses have suggested that coffee consumption versus no coffee consumption is associated with an up to 17 percent risk reduction of all-cause mortality.
• A study by Imperial College London found that participants with the highest consumption of coffee had a lower risk of all causes of death.
• A study from the US found that participants who consumed a cup of coffee a day were 12 percent less likely to die compared to those who didn’t drink coffee.

“Data on cause of death and years lived combined with life expectancy data can be a useful way to understand the general population’s health, and is research frequently examined by health organizations to help inform policy to guide people towards healthier diets and lifestyles. The growing body of research on coffee consumption and all-cause mortality presents new data for consideration, although more evidence is needed to understand the association and mechanisms behind the results,” says Sian Porter, Consultant Dietitian and spokesperson for the British Dietetic Association, UK.

Furthermore, the report notes context is everything when it comes to coffee's health benefits: “a coffee enjoyed as part of a healthy diet and lifestyle can be beneficial, but a coffee accompanied by a cigarette is unlikely to have much, if any, health benefit. Another important factor is how people drink their coffee; for example, adding sugar and cream adds calories, which people may not realize all counts towards their daily intake,” Porter tells NutritionInsight.

Should health practitioners recommend coffee to their patients?
Porter highlighted the importance of using appropriate language when communicating scientific research findings to the general public.

The roundtable agreed that the research on coffee consumption and all-cause mortality provides evidence-based information on the role of coffee in the diet, therefore, it was recommended that advice to drink coffee as a potential preventative measure could be given to patients specifically at risk of cardiovascular disease or type 2 diabetes, given the robust research base indicating that coffee can help reduce the risk of both conditions. It was added that some groups, such as pregnant women, should exercise caution over coffee intake.

NutritionInsight has previously reported on how coffee drinkers fall into one of three major groups based on their caffeine sensitivity: high, regular and low. This is potentially a further reason to exercise caution in recommending coffee to at-risk patients.

The European Food Safety Authority (EFSA) on caffeine intake advises 400mg caffeine per day for healthy adults and a 200mg limit for pregnant women. “The number of cups of coffee per day generally associated with reduced mortality risk (3-5) do match the EFSA definition of a ‘moderate’ daily intake, but it’s important to remember that this is not a case of ‘drink coffee and you’ll live longer’, or for non-coffee drinkers to suddenly start drinking coffee. As we discussed at the roundtable because research suggests that in a healthy population coffee has no adverse effects, people can safely drink coffee if they like it, as long as they stick to sensible amounts,” adds Porter.

By Laxmi Haigh