Growing epidemiological evidence has shown that plant-based dietary patterns (e.g., Mediterranean diet, DASH diet, etc.) are associated with improvements in cardiovascular health. What is less clear is the contribution of individual micronutrients or phytonutrients within these dietary patterns on cardiovascular risk reduction. One such phytonutrient is the phytochemical family—catechins, a group of flavonoids commonly found in cocoa, tea, legumes, grapes, apples, pears, and other plant-based foods.
Dr. Daniel Mangels from the Hospital of the University of Pennsylvania (HUP) and Dr. Emile Mohler III from the Perelman School of Medicine at the University of Pennsylvania published a review article in the journal Arteriosclerosis, Thrombosis, and Vascular Biology highlighting the current literature on the relationship between catechins and cardiovascular health.1 They found a large body of evidence supporting the role of catechins in blood pressure (BP) reduction, flow-mediated vasodilation (FMD), and atherosclerosis attenuation. The key findings are summarized below.
Effect of catechins on BP:
- Meta-analysis of 20 randomized controlled trials (RCTs) found that cocoa consumption was associated with a mean reduction in systolic BP by 2.77 mmHg and diastolic BP by 2.20 mmHg (p<0.01)
- Meta-analysis of 16 RCTs found that consumption of 25 mg of epicatechin (a specific catechins) reduced systolic BP by 4.1 mmHg and diastolic BP by 2 mm Hg (p<0.05)
Effect of catechins on FMD:
- Impaired FMD is an independent predictor of future cardiovascular events
- Multiple RCTs (sample size ranging from 20 to 60 subjects) showed that flavanol-enriched cocoa, flavanol drink, or pure epicatechin improved FMD in a dose-dependent fashion
- The mechanism of flavanol-induced vasodilation is nitric oxide dependent
Effect of catechins on atherosclerosis:
- As atherosclerosis develops over a prolonged period of time, most of studies assessing the effect of catechins intake on this condition are based on epidemiological studies
- A large cohort study including nearly 35,000 postmenopausal women showed an inverse relationship between consumption of foods rich in catechins and deaths from coronary artery disease, even after adjusting for other risk factors
Although the accumulating evidence is compelling, the authors cautioned that RCTs that exhibit statistical significance do not necessarily translate to clinical significance. Also, plant foods that contain catechins may also contain other beneficial phytochemicals. Several relevant human studies did not include information on participants’ use of antihypertensive medications. Further, consuming large amounts of catechins-rich foods such as chocolate may be accompanied by increased intakes of sugar.
Why is this Clinically Relevant?
- A growing number of studies have demonstrated the benefits of plant-based diets for cardiovascular health
- One of the benefits of plant-based diets may be related to increased consumption of catechins
- Mechanistically, catechins have a role in blood pressure reduction, flow-mediated vasodilation, and atherosclerosis attenuation
Citation
1. Mangels DR, Mohler ER. Catechins as potential mediators of cardiovascular health. Arterioscler Thromb Vasc Biol. 2017;37(5):757-763.
