Before you treat yourself to a delicious milkshake, you may want to consider whether it is the right choice. After a recent study, milkshakes have been negatively correlated with stress on your blood vessels and damage to your red blood cells.

In the experiment, ten healthy men were given a milkshake (80g of fat and 1000 calories) to drink, and then tested for the differences in their biological health. When the results were in the hands of the researchers, they noticed that each participant’s blood vessels could not dilate or had difficulty relaxing. A handful of their red blood cells had become characterized as “spiky,” as opposed to the regular rounded and smooth shape. This was after only one milkshake.

Professor of cell biology, Julia Brittain, says that there is no need to worry if you are a healthy person and decide to have a milkshake or two every so often. The symptoms clear up quickly for averagely healthy individuals, but over time, she notes, “it will add up.” Ultimately, Brittain’s study revealed that milkshakes are severely dangerous for your vascular health in the long term.

You don’t need to stop drinking milkshakes, but scientists and researchers involved in this study warn to limit your fat intake to 20-30% a day if you are a healthy individual, just to be safe.