This study points out that regular nut consumption reduces cardiovascular disease risk, partly from improvements to dietary quality. And the nutrients that are increased when you eat them (particularly, in this case, hazelnuts) include fiber, protein, total fat, MUFA, PUFA, potassium, folate, and vitamin E.
This may be because nuts (in this study it was almonds) can lower total and LDL cholesterol, effectively cleaning up your blood from the harmful effects of the bad cholesterol. Pistachios too also lower the bad stuff, and increase the good stuff.
The point is that, if you need a snack, reach for the nuts because they’re super heart healthy — as well as being delicious!!