Chronic coronary syndrome (CCS) is the leading cause of death in women in the most developed regions of Brazil. The primary etiopathogenic mechanism is the process of atherosclerosis. A healthy diet rich in fruits and vegetables is associated with a lower incidence of CCS. The higher consumption of these foods promotes greater availability of phenolic compounds, and the higher intake of these compounds is one of the main hypotheses for vascular health. Quercetin, a phenolic compound, is the most abundant natural antioxidant belonging to the group of flavonoids. Quercetin improves lipoprotein metabolism, has an antioxidant capacity, produces vasodilating substances in the vascular endothelium, and reduces platelet aggregability. Likewise, statins are medications known to reduce cardiovascular events in women with CCS by reducing serum LDL-cholesterol levels and, to a lesser extent, by possible pleiotropic effects. In turn, SIRT1 is one of the 7 classes of proteins. It mediates various metabolic pathways in response to nutritional stimuli, particularly for caloric restriction and phenolic compounds, as well as coordinating the production and secretion of important hormones. However, the impact of quercetin supplementation and statin administration on serum endogenous estrogen levels is unknown

The main objective of this study is to investigate the influence of atorvastatin and of quercetin in the serum concentrations of estradiol and estrone after the administration of atorvastatin and supplementation with quercetin. This is a randomized, double-blind, placebo-controlled, 60-day study in 60 postmenopausal women with CAD, divided into three groups of 20 women each: Group 1 - quercetin (500 mg/day); Group 2 - atorvastatin (80 mg/day); Group 3 - control (placebo).

Inclusion Criteria:

• Postmenopausal women;
• Diagnosed coronary artery disease;
• Stable coronary disease;

Exclusion Criteria:

• hypo or hyperthyroidism,
• rheumatic disease,
• use of alcohol,
• hepatic failure,
• renal failure
• hormone replacement therapy
• use of insulin

Participants in the control group will receive capsules identical to those in the intervention group, but with cornstarch.

The care provider and the participants do not have the information about which capsules the participant is taking, and do not have access to which groups the patients belong. Statistical analyses will be performed on a blinded database, i.e. without information of which groups the participants belong to.

Only the principal investigator of the study has this information.