This piece originally appeared on Fix.com.
It’s hard to imagine birthday cakes without colorful writing, vibrant flowers, or other exciting designs. But the colors in our cakes, candies, and other popular foods may not be as innocuous as their pretty exteriors would lead us to believe.
Research suggests that synthetic food coloring may harm human health in a variety of ways. But in spite of the risk factors, these colorants are cropping up in more foods than ever before. Although they provide no nutritional value, they’re added to a wide range of foods to intensify color or give those foods the color people expect to see. (For example, boxed cake batters may be dyed yellow in to look like they’re made from real eggs.)