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 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.

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.

Mice eating olive oil and nuts had more of the good fats (like olive oil and nuts) and less of the bad fats (like butter) in their blood than mice eating a typical fatty diet.

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.