Can you use a regular paint brush for basting food?

It depends on the type.

The real inexpensive ones tend to loose bristles so they may end up in your food.

Some of the synthetic ones can melt at higher temperatures so if you are basting on a hot piece of meat the bristles may start to melt. And do not leave the brush in the sauce if it is on a burner keeping warm.

If it is all you have for the moment use it but then I would toss it.

A paint brush has a metal ring that helps keeps the bristles attached it is possible that you will not be able to clean well enough under the metal band and that could allow bacteria to grow.

Next time you are out pick up a silicone basting brush they are inexpensive and can easily be washed and can be used at higher temperatures.

a clean new one, yes.

Try those sponge brushes from the dollar store, there good, work for one go and then toss them, as a chef I used paint brushes, but be careful as said they sometimes lose there bristles, wash them good, dry in the air and store in a sandwich bag, just make sure no one uses it to paint the fence afterwards...

Yes, but better than that is the new silicone basting brushes. The paint brushes tend to loose hairs and you don't want to eat that.

I do. Obviously, they never get used for anything else.

Use the ones made of horse hair for a more earthy musky flavor

Or should you use a pastry brush!