Walnuts are crunchy, delicious, and oh-so-good for heart health. It is clearly established that walnuts lower cholesterol levels, but scientists recently set out to take a more in-depth look into other ways walnuts may shine for cardiovascular health. For this evaluation, scientist fed study subjects a single feeding of walnuts, walnut oil, walnut skin, and de-fatted walnut meal on four separate occasions. The scientist carefully monitored biochemical and functional responses in the blood vessels of the subjects before and after eating each of the four walnut preparations. After the walnut oil, the blood vessels of the study subjects exhibited significant improvements in endothelial function, a very valuable feature for cardiovascular protection.  After eating the whole walnuts, study subjects showed a boost in the activity of good (HDL) cholesterol with enhanced removal of bad cholesterol from the body.