Is it true? Do budget UV filters degrade quality?

I bought this set of filters for my G2 14-42 kit, basically to protect the lens.

Zeikos ZE-FLK52 52mm Professional MULTI-COATED Glass Filter Kit UV Polarizer
http://www.amazon.co.uk/gp/product/B001KNAWZ4/ref=oss_product

A friend of mine advised against using ANY UV filter, saying it degrades the IQ massively?

He also went on to say that even expensive filters, like HOYA, would also do the same?

Is that true?

Is there no point in buying an expensive filter? Do all degrade IQ?

Thnx