Recent studies of lower and middle socio economic groups of African Americans and Chinese men and women showed an inverse association of nut (predominantly peanut) consumption and death from heart disease. Furthermore eating peanuts decreased respiratory disease and cancer.
Yes technically the peanut is not a nut since it grows in a bush and not a tree but they are inexpensive easily available and GOOD for your heart!
The American Heart Association and American College of Cardiology specifically includes nuts as part of a recommended dietary pattern to reduce atherosclerotic risk. A detailed in depth paper is worth a read or a skim there is a good table of contents to assist.