I don’t blame you if you are thoroughly confused. On an everyday basis, there is breaking news offering you the latest in nutrition science. Coffee is good for you. Coffee is not good for you. Hot coffee causes cancer. Well actually, maybe it does not after all. Arguments are made about all kinds of nutrients. The Internet amplifies them. Quacks of all kind (present company excluded, hopefully) offer advice as though they conducted the research themselves. Such is the level of interest that fluffy magazines about entertainment have whole sections dedicated to nutrition. Everyone is an expert; they would have you believe. So what should you make of it?
Here is the harsh truth. The science of nutrition is complicated. When you are evaluating the impact of hot coffee on sapiens, imagine the normalization required. The cohort all have to be from a similar gene pool, of the same age, backgrounds, economic status, and habits. Their diets have to be analogous to ensure that it is not the rest of their diet impacting them positively in some way. If I said, finding such a cohort is well nigh impossible, I would not be exaggerating. Let us say that by some miracle you do find a group like this. This group has to drink hot coffee continuously day after day. The coffee drinking has to go on for a relatively extended period before you can begin to evaluate the impact. What are the odds that people will cheat, drop out or dilute their habit? You also need to account for the placebo effect and hide the factor being tested. Try hiding hot coffee!
Scientists find that somehow, humans seem to have a mind of their own. For these reasons, animals are used for studies. A study in mice does not easily translate to sapiens. Therefore, the next time you hear of a miracle discovery, take it with a pinch of salt; or hot coffee perhaps.