For a healthier heart, indulge in the snack food that contains a collection of natural chemicals that provide your heart with jaw-dropping (and blood pressure-dropping) benefits. Eating walnuts in a heart-healthy diet can lower blood cholesterol levels. The oil in walnuts improves the performance of blood vessel walls and helps HDL (good) cholesterol keep the arteries functioning more efficiently. The oil found in walnuts can maintain blood vessel function after a meal, which is very important given that blood vessel integrity is often compromised in individuals with cardiovascular disease. The walnut oil is particularly good at preserving the function of endothelial cells, which play an important role in cardiovascular health. Simple dietary changes, such as incorporating walnuts and/or their oil in a heart healthy diet, may reduce the risk of heart disease.