What type of study was this? Was it an experiment or a correlational study? Was it a survey? How long was the study period? How many people were recruited for the study, how were they recruited, and from where? How old were they? What other variables were recorded about the individuals? Were changes made to the participants’ coffee habits during the course of the study? Where was the study published? Was it a peer-reviewed article?

What type of data was collected? What graphs are relevant, and what do they reveal? What descriptive statistics can be calculated to summarize relevant aspects of the data? What patterns can we see in the data? Are there any individual observations that deviate from the overall pattern, and what do they reveal? For example, did the proportions differ for life longevity if we compared smokers to the non-smokers? Are the results statistically significant? Is the 10%–15% reduction in risk of death something that could have happened just by chance?

Who do you think these conclusions apply to? (Were the people in the coffee study older? Healthy? Living in cities?) Can you draw a cause-and-effect conclusion about your treatments? Are scientists now saying that coffee drinking is the cause of the decreased risk of death?

When researchers study the effects of something like coffee on mortality, they need to consider other factors that could also be affecting mortality, like smoking or age. So, they do what’s called an “age-adjusted analysis” where they look at the data while taking into account the age of the people being studied.

Initially, the researchers found that in their age-adjusted analyses, coffee consumption seemed to be linked to an increased risk of dying for both men and women. However, they also found that when they took into account other factors that could be influencing the results (like smoking), there was actually a small decrease in the risk of dying for both men and women who drank coffee. In short, after considering other factors that could be affecting the results, the researchers found that drinking coffee was actually associated with a slightly lower risk of dying for both men and women.

When researchers do a “multivariate adjustment”, they take into account many different factors that could be influencing the results. In this case, the researchers looked at whether there was a connection between drinking coffee and different causes of death, like heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections.

What they found was that after taking into account all these other factors, drinking coffee appeared to be linked to a lower risk of dying from most of these major causes of death, both for men and women. So, it seems that coffee may have some protective benefits against a range of diseases and health conditions that can lead to death.

Researchers found that there was no significant association between coffee consumption and deaths from cancer in women. This means that drinking coffee did not appear to increase or decrease the risk of dying from cancer in women.

However, in men, the researchers did find a borderline positive association between drinking coffee and deaths from cancer. This means that men who drank six or more cups of coffee per day had a slightly higher risk of dying from cancer than men who drank less coffee.

Some studies have found that drinking coffee may actually lower the risk of developing diabetes, which is a good thing. However, it’s also been found that people who drink coffee tend to engage in other behaviors that can be unhealthy and increase the risk of death. These include things like smoking tobacco, eating a lot of red meat, and drinking a lot of alcohol. So even though coffee itself may have some health benefits, people who drink coffee may also have other unhealthy habits that outweigh those benefits. In other words, just because someone drinks coffee and may have a lower risk of diabetes doesn’t mean that they’re necessarily overall healthier or at a lower risk of death, especially if they engage in other unhealthy behaviors.