I'm 50 next year and suspect that I'm showing symptoms. had first ever coil fitted last year post-divorce but periods had already changed and were coming more regularly ie every 30 days instead of anywhere from 28 to 60 days apart. But the last three months I've been bleeding around 3 weeks apart which is annoying.
Memory fog definitely an issue, as is concentration (or lack of!). Been relatively lucky with the lack of hot flushes but body temperature is definitely harder to regulate - does anyone else sleep with their legs out of the covers ?! 
Hopefully I will be like my mum and grandma and have a fairly easy time - my diet is good, not much meat, I'm not overweight, I exercise almost every day, so I'm hoping that will be OK! Would love to know if anyone has any vitamins/minerals they can recommend?