Drinking 2 to 3 cups of coffee per day could have a surprising effect on longevity

A new study conducted by Australian scientists suggests that consuming two to three cups of decaffeinated, ground, and instant coffee can lower the risk of developing cardiovascular disease and dying early.

Scientists also believe that the benefits of the drink come from chemicals in coffee beans rather than caffeine.

"In this large, observational study, ground, instant, and decaffeinated coffee were associated with equivalent reductions in the incidence of cardiovascular disease and death from cardiovascular disease or any cause," says study author Professor Peter Kistler of the Baker Heart and Diabetes Research Institute in a media release.

"The results suggest that mild to moderate intake of ground, instant, and decaffeinated coffee should be considered part of a healthy lifestyle."

Tracking the health of nearly 450,000 volunteers

Examining data from the U.K. Biobank, an ongoing study that analyzes the health of the country's citizens, the research team gathered information about the dietary habits of the volunteers, specifically how much and what kind of coffee they generally drink.

At the start, researchers monitored the health and death of nearly 450,000 volunteers, who were over the age of 40 and had no documented cardiovascular disease, for longer than a 12-year follow-up period. The results have shown that compared to non-coffee drinkers, coffee drinkers are less likely to develop cardiovascular disease and die from any cause in general.

However, these advantages were also dependent on the amount and the type of coffee consumed. The biggest decrease in mortality was observed in those who consumed two to three cups of decaffeinated, ground, or instant coffee per day.

Those who drank one to five cups of ground and instant coffee per day had the lowest risk of developing arrhythmia, or an abnormal heartbeat while decaf hasn't shown any protective effects.

"Drinking modest amounts of coffee shouldn't be discouraged"

“Caffeine is the most well-known constituent in coffee, but the beverage contains more than 100 biologically active components. It is likely that the non-caffeinated compounds were responsible for the positive relationships observed between coffee drinking, cardiovascular disease, and survival,” said study author Peter Kistler, a researcher at the Baker Heart and Diabetes Research Institute in Melbourne, in a statement from the European Society of Cardiology, the journal’s publishers.

"Our findings indicate that drinking modest amounts of coffee of all types should not be discouraged but can be enjoyed as a heart-healthy behavior."

The research is another addition to a long series of research on the effects of coffee on health. Current studies, however, cannot demonstrate a causal association. Therefore, randomized clinical trials are still needed to fully comprehend the connection between coffee and health.

The study was published in the European Journal of Preventive Cardiology.

Abstract:

Aims: Epidemiological studies report the beneficial effects of habitual coffee consumption on incident arrhythmia, cardiovascular disease (CVD), and mortality. However, the impact of different coffee preparations on cardiovascular outcomes and survival is largely unknown. The aim of this study was to evaluate associations between coffee subtypes on incident outcomes, utilizing the UK Biobank.

Methods and results: Coffee subtypes were defined as decaffeinated, ground, and instant, then divided into 0, <1, 1, 2-3, 4-5, and >5 cups/day, and compared with non-drinkers. Cardiovascular disease included coronary heart disease, cardiac failure, and ischaemic stroke. Cox regression modelling with hazard ratios (HRs) assessed associations with incident arrhythmia, CVD, and mortality. Outcomes were determined through ICD codes and death records. A total of 449 563 participants (median 58 years, 55.3% females) were followed over 12.5 ± 0.7 years. Ground and instant coffee consumption was associated with a significant reduction in arrhythmia at 1-5 cups/day but not for decaffeinated coffee. The lowest risk was 4-5 cups/day for ground coffee [HR 0.83, confidence interval (CI) 0.76-0.91, P < 0.0001] and 2-3 cups/day for instant coffee (HR 0.88, CI 0.85-0.92, P < 0.0001). All coffee subtypes were associated with a reduction in incident CVD (the lowest risk was 2-3 cups/day for decaffeinated, P = 0.0093; ground, P < 0.0001; and instant coffee, P < 0.0001) vs. non-drinkers. All-cause mortality was significantly reduced for all coffee subtypes, with the greatest risk reduction seen with 2-3 cups/day for decaffeinated (HR 0.86, CI 0.81-0.91, P < 0.0001); ground (HR 0.73, CI 0.69-0.78, P < 0.0001); and instant coffee (HR 0.89, CI 0.86-0.93, P < 0.0001).