I've had highlights for over 30 years! I get them done professionally. It's probably about 5% of my hair, so that's all that could be damaged. I get my hair cut every 6 weeks.

Depending on what you do as far as color, I think that highlights (thin ones, rather than "chunky" ones) would be less damaging.
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08

SE PA

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic (now Hello Curly Curl Stimulater); Botanical Spirits Jellies, CJ Repair Me, Marie Dean Leave Ins and Curl Creams