Promising Potential of Dietary (Poly)Phenolic Compounds in the Prevention and Treatment of Diabetes Mellitus

Background: The incidence of diabetes mellitus (DM) is reaching alarming proportions worldwide, particularly because it is increasingly affecting younger people. This reflects the sedentary lifestyle and inappropriate dietary habits, especially due to the advent of processed foods in modern societies. Thus, unsurprisingly, the first medical recommendation to patients with clinically evident DM is the alteration in their eating behaviour, particularly regarding carbohydrates and total energy intake. Despite individual and cultural preferences, human diet makes available a large amount of phytochemicals with therapeutic potential. Phenolic compounds are the most abundant class of phytochemicals in edible plants, fruits and beverages. These compounds have strong antioxidant and anti-inflammatory activities that have been associated with specific features of their chemical structure. Among others, such properties make them promising antidiabetic agents and several mechanisms of action have already been proposed. Objective: Herein, we discuss the recent findings on the potential of dietary phenolic compounds for the prevention and/or treatment of (pre)diabetes, and associated complications. Conclusion: A broad range of studies supports the innate potential of phenolic compounds to protect against DM-associated deleterious effects. Their antidiabetic activity has been demonstrated by: i) regulation of carbohydrate metabolism; ii) improvement of glucose uptake; iii) protection of pancreatic β-cells; iv) enhancement of insulin action and v) regulation of crucial signalling pathways to cell homeostasis. Dietary phenolic compounds constitute an easy, safe and cost-effective way to combat the worrying scenario of DM. The interesting particularities of phenolic compounds reinforce the implementation of a (poly)phenolic-rich nutritional regime, not only for (pre)diabetic patients, but also for non-diabetic people.