We’ve all heard that walnuts can help our heart. They lower blood cholesterol and help prevent cardiovascular disease, but how do walnuts do this? Scientists knew that walnuts were an important part of a heart healthy diet but were not sure exactly what part of the walnut was beneficial. In a study results found that consuming walnut oil just once, increased the functioning of blood vessels. Eating whole walnuts was also beneficial in increasing good cholesterol. Omega-3 fatty acids and vitamin E are the beneficial nutrients in walnuts according to this study. While more research needs to be done on these findings, they do show an important step in nutrition research.