It is safe to consume three to four cups of coffee a day and it is probably more beneficial than harmful for the health, finds the new evaluation by Nutrimedia, a project of the Science Communication Observatory (OCC) of the Department of Communication at UPF, in collaboration with the Cochrane Iberoamerican Center (CCIB). This evaluation shows that the available research results have a very low degree of certainty and that it is therefore unsure or doubtful whether it can be stated that coffee is beneficial for the health. The Nutrimedia analyses establish five degrees of certainty about messages concerning food and health: true, probably true, probably false, fake and unsure.

To carry out this evaluation, the results of the main studies dealing with the effects of coffee on the health of the general population, including adults, pregnant women, children and adolescents were analysed. These studies show that drinking three or four cups a day, compared to not drinking any coffee, has a minimal effect on the reduction of the risk of death and cardiovascular disease; in addition, the results of the research show that high consumption of coffee, in comparison with low consumption, has a minimal effect on reducing the risk of suffering cancer.

Nevertheless, these results are deemed uncertain or doubtful due to their low degree of certainty. This is so firstly because most studies carried out are observational, and such studies, as a rule, have a very low degree of certainty. Moreover, these studies have other limitations arising from the rigour of their performance and from the disparity and impreciseness of their results. To clarify whether coffee really does have any beneficial -or harmful- properties, quality clinical assays are required.

Average consumption of caffeine per person is calculated at 165 mg/day of which over 60% is associated with the consumption of coffee. Other drinks and food, such as tea, chocolate and cola drinks are also sources of caffeine, though its content varies. Caffeine content also varies according to the type of coffee and how it is prepared. For example, it is calculated that a cup of instant coffee contains 100 mg of caffeine, whereas a cup of filtered coffee contains some 140 mg; a cup of tea contains 75 mg of theine (caffeine and theine are the same molecule with a different name, depending on where it is found); a cola drink can contain up to 40 mg of caffeine; a bar of dark chocolate may contain up to 50 mg, whereas milk chocolate contains about half.

Safety limits for the consumption of caffeine are set at 400 mg a day for healthy adults, according to medical guidelines. Children and adolescents should not exceed 2.5 mg per kilo of weight (children from 4 to 6 years, a maximum of 45 mg a day; from 7 to 9 years, a maximum of 62.5 mg a day, and children of 10 to 12, no more than 85 mg a day), although further studies are required to find out about the long-term effects of caffeine consumption. in the case of women who are pregnant, lactating or trying to get pregnant, the recommended limits range from 200 to 300 mg a day, due to the possible relationship between the consumption of caffeine and low birth weight.

Reference work:

Nutrimedia technical report:  https://tinyurl.com/y8cwemvw