This might explain why people who often eat nuts live longer.
Consumption of whole walnuts or their extracted oil can reduce cardiovascular risk through a mechanism other than simply lowering cholesterol,...
"We already know that eating walnuts in a heart-healthy diet can lower blood cholesterol levels,"...
... a one-time consumption of the oil component in walnuts favorably affected vascular health. In addition, consumption of whole walnuts helped HDL -- good cholesterol -- perform more effectively in transporting and removing excess cholesterol from the body.
"Our study showed that the oil found in walnuts can maintain blood vessel function after a meal, which is very important given that blood vessel integrity is often compromised in individuals with cardiovascular disease," ... "The walnut oil was particularly good at preserving the function of endothelial cells, which play an important role in cardiovascular health."
According to the researchers, walnuts contain alpha-linolenic acid, gamma-tocopherol and phytosterols, which may explain the positive effects of the walnut oil treatment.
"Our study indicates that simple dietary changes, such as incorporating walnuts and/or their oil in a heart healthy diet, may reduce the risk of heart disease," she said. [emphasis mine]
I love walnuts. A good reason to eat them.