Polyphenols are a diverse group of plant-derived compounds found in foods such as tea, cocoa, berries, and red wine. Their potential benefits in cardiovascular health, including angina, are primarily attributed to their antioxidant and endothelial function-enhancing properties. Several epidemiological studies suggest that diets rich in polyphenols are associated with a reduced risk of coronary artery disease, which is the underlying cause of angina. Experimental and small clinical studies have shown that certain polyphenol-rich extracts (like those from grapes or cocoa) may improve endothelial function, decrease platelet aggregation, and reduce oxidative stress, all of which are relevant to the pathophysiology of angina.

However, direct clinical evidence supporting the use of "mixed polyphenols" specifically for the treatment or symptomatic relief of angina is limited. Most studies focus on surrogate markers (such as endothelial function or blood flow) rather than direct angina outcomes. There are a few small trials (e.g., with grape polyphenol extracts) that report improvements in endothelial function in patients with stable coronary artery disease, but large-scale, high-quality randomized controlled trials assessing the effect of polyphenol supplementation on angina frequency, duration, or severity are lacking.

In summary, while there is some scientific rationale and preliminary evidence suggesting a potential benefit, the direct evidence for using mixed polyphenols to treat or support angina is limited and not definitive.