Is coffee healthy? Recent study tries to answer age-old question

Coffee drinkers probably draw health benefits from their preferred beverage, according to an international research team. The report, based on data about the deaths of half a million people from a total of 10 European countries, was recently published in the medical journal Annals of Internal Medicine. It showed, for example, that the probability of dying within the observation period, about 16.4 years, was 12 per cent lower for male participants with a very high consumption of coffee than for those who did not drink coffee. Among women, this probability was 7 per cent lower for coffee drinkers. In order to look at the health effects of coffee in isolation, researchers eliminated many other factors, including diet and whether the participants smoked. Research team leader Marc Gunter tones down excitement around these results, however. “Given the limits of observational research, we are not at a point where we can speak for greater or lesser coffee consumption,” Gunter admits. Still, the results of this study indicate that moderate coffee consumption, about three cups per day, not only does not damage health but actually might have health benefits. Gunter Kuhnle, of the University of Reading in Britain, is less optimistic. Kuhnle, a nutritional biochemist who was not involved in the study, believes the impact of these results is rather limited. Kuhnle notes that reports of this kind tend to be subjected to sensationalism, although they usually say nothing about causality. In this case, the research does not establish whether it is really coffee that caused the observed effect. According to the research team that carried out the study, coffee is one of the most popular drinks in the world: People around the globe are believed to drink an estimated total of 2.25 billion cups per day, even though coffee was for a long time considered unhealthy. Last year, the International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), said that there was no evidence that coffee increased the risk of cancer. The most recent study now joins a growing number of research projects that challenge coffee’s traditionally negative image or even put forward its positive effects. Studies carried out in the US and Japan have reached similar conclusions. This latest study, with input from researchers from IARC and from Imperial College London, observed that people who drank more coffee faced lower risks in relation to all the causes of death that were surveyed, particularly circulatory diseases and illnesses related to the digestive tract. “Our study offers ... important insights into the systems that probably account for coffee’s positive effects,” Gunter says. “We found that drinking more coffee was linked to more favourable liver function tests and better immune responses.” Kuhnle notes this has already been shown in previous studies, but not as accurately. He believes this research fills a gap by establishing for Europe a relationship between coffee consumption and total mortality that had already been researched for the United States. However, Kuhnle is above all interested in the question of why the mortality rate is higher among people who drink a lot of coffee. “Is this an effect of the bioactive compounds in coffee, so that one could then isolate them or better prepare the coffee, or is there a different reason?” he asks. It is also possible that these health effects in fact have nothing to do with coffee, but rather that the beverage is merely linked to the real cause of those effects. For example, it may be the case that people with increased risks of suffering various diseases generally drink less coffee. Still, this study indicated that coffee consumption is at least not unhealthy; whether it is actually healthy is a different question. — dpa