Hypertension is one of the main cardiovascular risk factors in the elderly population and its control has become a key health priority for public health organisations. The adoption of a heart-healthy lifestyle is recommended, including a diet rich in fruits and vegetables, maintaining a body mass index between 18.5 and 24.9 kg/m², and performing physical exercise.

Research on polyphenol health effects began relatively late, not until 1995, probably because they are not essential nutrients and have very diverse chemical structures, with more than 800 different organic structures found in nature.1 This hampers their analysis in foods and even more so in biological fluids, since they have low bioavailability. Another complication is that polyphenols can be metabolised by intestine or hepatic cells, or by intestinal microbiota when they arrive in the large intestine. Over the last two decades, the literature on polyphenols has grown exponentially following …