Claims that regular coffee drinking causes obesity are being refuted, due to the source study being based on the effects of a concentrated chemical on mice. The study, conducted by universities in both Australia and Malaysia, was published in the Journal of Agricultural and Food Chemistry. The research emerged from a desire to better understand ‘metabolic syndrome’, a medical term for the combination of obesity, diabetes and high blood pressure which increases the risk of heart disease and stroke. This is a condition which has become more and more of an issue over recent years. In the study, chlorogenic acid, or CGA, was the substance found in coffee which was given to the mice, in order to analyse the effect it had on their fat and glucose levels. The rodents given CGA alongside a high-fat diet showed worse glucose regulation, than those given only a high-fat diet. The results were quickly applied to coffee by extension, thus the claim that drinking coffee regularly could lead to weight gain.
Whilst many assumed that the worse glucose regulation in the rats given CGA linked coffee-drinking to obesity, this study doesn’t say how often or how strong the coffee would have to be drunk in order for the CGA in it to affect glucose regulation, so it is problematic to compare the conditions and results of the study to the average coffee drinking human.
Previous observational studies on humans had found that humans who drank coffee regularly had lowered risk of type 2 diabetes. The aim of the study was to see if CGA had a beneficial effect on glucose and weight regulation. The conclusion the researchers themselves drew, however, was that their results did not support this, and could not be said to help prevent or reduce the effects of metabolic syndrome. Other studies found the opposite result in mice, and that CGA was beneficial. Since these results contradict each other, it can be said that CGA is not the thing that needs to be understood better, but the biological processes involved.