Both my mother and my brother quit smoking when the were in their 50's. Within 5 years, both started showing the signs and were subsequently diagnosed with crippling rheumatoid arthritis. My brother's doctor went out on a limb and shared his experiences with this phenomenon with my brother. He'd seen it quite a few times in his career. Rheumatoid arthritis is hereditary and those who inherit it will usually starts showing signs of it in their mid-thirties or even younger. The doctor was of the opinion that my brother's use of nicotine had delayed the onset as long as he'd continued smoking. He advised my brother not to pick up the habit again however, as my brother also has a history of heart disease. But that's another issue.