Heart Health Benefits of Consuming Leafy Greens

By Michelle Routhenstein, MS RD CDE CDN,  Cardiology Dietitian, and owner of EntirelyNourished.com.

Leafy green vegetables provide an abundant amount of heart health benefits. Having a variety of green leafy vegetables allows you to reap its various benefits. In this article, we will highlight the benefits of these nutrients and discuss what makes them cardioprotective.

Spinach, Swiss chard, arugula, cabbage, and kale are high in nitrates. These nitrate-rich vegetables convert into nitric oxide in the body, which is a potent vasodilator that helps to lower blood pressure and improve vascular function. In this randomized controlled crossover study, meals that had 220 mg of nitrate derived from spinach, lead to a higher large artery elasticity index, lower pulse pressure, and systolic blood pressure, indicating an improvement in arterial stiffness.

Green leafy vegetables, particularly kale, are rich in flavanols, specifically kaempferol, and quercetin, which have been shown to help prevent cardiovascular disease. The main cause for this is due to their antioxidant, antiatherogenic, and antithrombotic properties. In this meta-analysis, quercetin and kaempferol were linearly associated with a lower risk of coronary heart disease and cardiovascular disease, respectively.

It is important to note that there is not just one nutrient that makes green leafy vegetables a superstar in a heart-healthy diet. Green leafy vegetables are nutrient-dense and are rich sources of potassium, magnesium, folate, and vitamin K, micronutrients that are essential for optimal heart health.

Potassium plays many roles in heart health. The mineral helps maintain a regular heartbeat and normal blood pressure. In this systemic review and meta-analysis of 22 randomized controlled trials and 11 cohort studies, increased potassium lowered the incidence of stroke by 24%. The highest levels of potassium are found in Swiss chard and spinach leafy greens.

Magnesium is also an important nutrient for heartbeat regularity. If you have low magnesium levels, you are more likely at risk for irregular heartbeats and palpitations. This mineral is found in many leafy green vegetables such as collard greens and cabbage.

When someone is deficient in folate, it can lead to high homocysteine levels which can increase the risk of atherosclerosis. Folate helps to break down homocysteine, an amino acid that can cause damage to the walls of the arteries. You can find this nutrient concentrated in romaine and spinach leafy greens.

Vitamin K1 is found in many green leafy vegetables like Swiss chard, endive, and escarole. It plays an important role in bone health and vascular calcification, along with helping with blood clotting. Vitamin K has also been associated with a reduced heart failure risk. In this study, high vitamin K status was associated with decreased left ventricular mass index in women. The reason Vitamin K found in leafy greens may help with reducing the burden on the heart and preventing heart failure is because of the role it plays in absorbing calcium into the bone and preventing potential calcification in the arteries.

Overall, aim to eat a variety of green leafy vegetables to reap the abundant benefits and nutrients they contain. Each leafy green has a different advantageous nutrition profile. To make leafy green vegetables become part of your diet, look for variety in how you prepare them. For instance, if you enjoy salads and you always gravitate to one green leafy vegetable like romaine, perhaps next time add in a handful of another leafy green, like shredded cabbage or arugula. If you enjoy smoothies, a handful of spinach adds a heart-healthy boost without changing the flavor. Greens can also be easily incorporated into most sauces, soups, stir-fries, or scrambles. Some of my personal favorites are to add arugula on top of my avocado toast or to a veggie egg white omelet.

The benefits of green leafy vegetables for heart health are clear, and we need to incorporate them regularly into our diets to protect our hearts.