Warped/bowing roof beam

[octpods]

Our house is 1880 and I think these roof beams are just as old... They're looking fairly bowed and been like that since I moved in 10 years ago. Would this be of any concern?

 

[John D v2.0]

Unless the roof covering has been replaced edit-with something heavier or a strut removed, I'd go for the principle of it's not going anywhere.
You can look down the street and see if it's similar to the rest, assuming there are rows of similar houses.

 

[datarebal]

The roof has been replaced.
an outside picture might help , I'd guess its been stripped and interlocking tiles fitted.. look to fit struts off the purlin to stop further stress

 

[Wayners]

I'd recommended treating timbers and adding more supports as above.
Some roofs around me have had heavier concrete tiles fitted Vs the original slate tiles causing problems