Male-34 years short and longhaul BA, 5 years independent. The first few years were a constant succession of colds, flu each year. Frequent headaches inflight, and bone-aching tiredness and fatigue. Busy months utterly, desperately fatiguing, and rather too occasional migraine headaches. After a few years, you really do get an immunity from the bugs. Effects of the job long term seem to be weight gain for pilots (inactivity and drinking), many female cabin crew (children and lack of time for exercise), and male cabin crew (drinking and lack of exercise), and divorce. Many pilots suffer gradual long term blood pressure problems, but that may be because the group is more closely monitored than the general population. Radiation effects do not seem more severe than general- I calculated as a longhaul crew I got up to about 5x normal population exposure
I do not feel airline crews suffer extraordinary health effects. I do monitor mortality amongst my former colleagues post retirement. Pilots do seem to exceed average population death ages. Most prevalent cancers appear to be skin melanoma, brain tumours, prostate, bowel (sedentary and lack of exercise), and of course the out of the blue heart attacks. You are not shortening your life doing this job, the weird hours/early starts/long working days do absolutely no detectable damage. What does make a massive difference is:
1- sensible, not excessive exercise
2- not smoking
3- keeping alcohol consumption under control
4- weight control
5- monitoring health (BP, blood, skin, digestion, lumps and other inside things- you know what)
Incidently, it's been calculated that the classic airline exercise -golf, is NOT beneficial health wise. Golfers have exactly the same mortality as the general equivalent population. It's thought the massive muscle contraction across the chest damages the heart to wipe out the freshair/walking benefits (which don't exist with motorised golf trolleys!). And give up squash after 40.
Quite simply, those 5 do it. It's not the job that is bad for you. It's being alive! Discussing concerns early is important and following through properly. I've been under BP treatment for 12 years. I have pituitary/hormone problems. I make the medics work for their money- my GP hides when I go in the surgery but I make sure they deliver the goods (me!).