The immune cells in mice eating olive oil and nuts had fewer 'danger signals' on their surface than those eating a fatty Western diet, making them less likely to trigger inflammation.

The plaques in mice eating olive oil and nuts had fewer inflammatory immune cells inside them than plaques in mice eating a fatty diet.

When immune cells from mice eating olive oil and nuts were provoked in a lab, they released less of the inflammatory chemicals than cells from mice eating butter.

When immune cells from mice eating olive oil and nuts were tested in a dish, they absorbed less of the bad cholesterol that clogs arteries than cells from mice eating butter.

Mice eating olive oil and nuts had fewer fat-filled immune cells in their blood than mice eating butter, which may help prevent artery damage.

Mice that ate olive oil and nuts instead of butter had less cholesterol and fat in their blood, which might help keep their arteries from getting clogged.