Spanish researchers have found a positive correlation between coffee consumption and a lower risk of mortality.
Living Longer with Coffee
I won’t set off fireworks immediately, but as a caffeine fan, I do find joy in such news. Especially when you hear them three times in one year.
Researchers from the University of Navarra utilized data from a Spanish cohort study in which more than 22,500 graduates participated (SUN project). For the ‘coffee study’, nearly 20,000 participants with an average age of 37 were selected from this cohort. These participants were then followed for 10 years. The diet was initially recorded through surveys. The researchers then examined the extent to which coffee consumption at the beginning of the study influenced the risk of mortality.
During those 10 years, 227 participants died. Participants who drank at least four cups of coffee per day had a 64 percent lower risk of death (from any cause) than people who didn’t drink coffee at all. For every additional 2 cups per day, the risk of death decreased by 22 percent.
The researchers also investigated whether gender, age, and adherence to the so-called Mediterranean diet influenced the association between initial coffee consumption and the risk of mortality. This association appeared to depend, among other factors, on age. In people over 45 years old, the risk of death decreased by 30% for every 2 additional cups of coffee per day. However, in younger participants, there was no significant difference. This latter finding doesn’t seem very surprising to me. The influences of diet on health often have a cumulative effect over time. In this study, all causes of death were considered. One can imagine that younger people may have more unusual causes of death. The influence of diet in general, and specifically coffee, would then be smaller.
In the SUN project we found an inverse association between drinking coffee and the risk of all-cause mortality, particularly in people aged 45 years and above. This may be due to a stronger protective association among older participants.
Our findings suggest that drinking four cups of coffee each day can be part of a healthy diet in healthy people.
– Dr Navarro, Hospital de Navarra, Pamplona, Spain
Year of Coffee Research
This isn’t the first study on coffee intake and life expectancy. This year, the same findings were made in two other cohort studies.
American researchers were particularly interested in the effects of coffee consumption in non-white populations [2]. They used data from the MEC (Multiethnic Cohort) study. From this, they selected data from 185,855 black Americans, Hawaiians, Japanese-Americans, Latinos, and whites aged 45 to 74 years old. A large, diverse population indeed.
In the follow-up, 58,397 participants died over a total of over 3 million person-years. Coffee consumption was associated with a lower risk of mortality after adjusting for risk factors such as smoking. Compared to people who didn’t drink coffee, the ratio for the risk of death at 1 cup per day was 0.88. For 2 to 3 cups, as well as for more than four cups of coffee per day, this ratio was 0.82. So here too, we see the positive influence (or rather the negative correlation with death) of coffee, where two to four cups of coffee per day would yield a greater benefit than one cup of coffee. It seems to be a good year for coffee. This year also saw the results of a large multinational European study on the association between coffee consumption and the risk of death [3] being announced. Researchers from various European institutions utilized data from the EPIC cohort study. The data of 521,330 people from 10 European countries were used in the study. During the average follow-up of 16.4 years, 41,693 of the selected people died. Compared to people who didn’t drink coffee, heavy coffee drinkers had a significantly lower risk of death (men’s ratio 0.88, women’s ratio 0.92).
Association, Cause, and Effect
Here too, it must be emphasized once again that an association doesn’t automatically mean causality. It’s possible that coffee isn’t the cause of this lower risk of death. For example, because the habit of drinking coffee is shared by people who also share other habits that are the actual cause. Suppose, for example, that coffee drinkers are found to smoke less for whatever reason (which isn’t likely in practice).
Although researchers in these types of studies attempt to adjust for such known risk factors, it’s not certain that coffee is indeed associated with a lower risk of death but not the cause.
It’s also important to note that coffee consumption was only determined once in the studies and may have changed during the follow-up.
However, we can at least say that there’s no reason to believe that drinking coffee is an unhealthy habit. Either coffee promotes your life expectancy or coffee drinkers tend to have healthier habits. Both sound fine as a coffee drinker. After extensively discussing the positive effects of coffee for fitness enthusiasts, only the dentist seems to have a reason to complain about that black elixir.
References
- escardio.org/The-ESC/Press-Office/Press-releases/higher-coffee-consumption-associated-with-lower-risk-of-death
- Park SY, Freedman ND, Haiman CA, et al. Association of coffee consumption with total and cause-specific mortality among nonwhite populations [published online July 11, 2017]. Ann Intern Med. doi:10.7326/M16-2472. http://annals.org/aim/article/2643433/association-coffee-consumption-total-cause-specific-mortality-among-nonwhite-populations
- Gunter MJ, Murphy N, Cross AJ, et al. Coffee drinking and mortality in 10 European countries: a multinational cohort study [published online July 11, 2017]. Ann Intern Med. doi:10.7326/M16-2945. http://annals.org/aim/article/2643435/coffee-drinking-mortality-10-european-countries-multinational-cohort-study
