There is promising evidence that eating nuts on a regular basis can improve cardiovascular health and reduce the risk of coronary heart disease. Even though nuts are very high in fat, the fat they do contain is the "healthy" type of fat - mostly monounsaturated and polyunsaturated fats.

Does Peanut Butter Count?

Only if it's 100% peanuts. Peanut butter brands contain added sugar, and some contain added saturated fats. One or both of these ingredients may counteract any positive effects that the peanuts have.

I looked at the websites of a few major peanut butter producers, thinking that they would have the ingredients available. It was surprising to find that neither Peter Pan or Skippy brand peanut butter had their ingredients listed on their websites.

Health Benefits of Nuts - Covers some specific health benefits of nuts, in a way that is accessible to consumers. From Harvard Medical School and School of Public Health

Nutting But the Truth - Don't let the bad-pun fool you, this article provides useful information about the studies from Melissa Stevens, MS, RD, LD (that's a lot of titles). She's from the Cleveland Clinic.