Although medical science has not yet discovered the exact cause of rheumatoid arthritis, we do have some knowledge of what factors contribute to the development of the disease, and how lifestyle figures into the picture.
At this point in time, doctors understand that the immune system plays an important part in the development of RA, although they still do not understand exactly how the immune system is triggered to start attacking healthy tissues. Infections appear to play a part, but only infections by certain viruses, fungi, and bacteria – others appear to have no effect at all on RA onset, and even those that are suspected only show correlation, not causation, so it is yet to be proved that they actually cause arthritis. There is an element of heredity in the disease as well, but again, there is no direct, irrefutable link between your genes and the development of RA. There are genes that have been identified as being associated with RA, and while they do appear to increase one’s risk for developing RA, they have not been identified as the smoking gun either. In short, you may carry the genes for RA, but unless your body encounters the correct trigger (whatever that might be) the disease will likely never manifest itself. Essentially, the cause for RA is still mostly unknown.
There are several risk factors – some of which you can control, and others that you cannot – that add to the risk of developing RA. These risk factors, again, have not been identified as direct causes, but may increase your chances of triggering the disease. One of the risk factors is your sex. RA is far more common in women than it is in men, occurring in three times as many women as men. Age is another significant risk, since the vast majority of RA sufferers develop the disease between the ages of forty and sixty. There are cases where RA is diagnosed in children, but that is known as Juvenile Rheumatoid Arthritis, and while it affects more than 50,000 children in the US alone, it is not always a lifelong disease. Many children experience symptoms for a few weeks or months at some stage of their childhood, and never experience symptoms again.
Smoking appears to cause a higher risk of developing RA, and is possibly one of the factors that the immune system requires to trigger the disease. One of the problems with this is that the RA pain keeps people from moving, and so they sit much more, and therefore may increase the amount that they smoke, in order to counteract the boredom. Smoking is also associated with more severe forms of the disease as well, so it is best to quit smoking altogether – not just for your lungs, but for your joints as well.
There are other environmental exposures that are believed to serve as triggers for RA, including asbestos, silica, Vitamin D deficiencies, heavy manual labor, and possibly geography (some areas have far higher rates of RA than others) although none of the above has been definitively proven to cause RA. While smoking seems to have the greatest influence, people who are exposed to asbestos fibers or silica also carry a greater risk, which points to lung injuries as possibly being a factor. Vitamin D deficiencies are being examined as a possible trigger for RA symptoms, but only a tenuous link has been found so far. Heavy manual labor may also play a part in the development of RA, although that possible link is still being examined. The theory seems to be that heavy labor causes minor damage to the joints to begin with, which in turn triggers RA symptoms, eventually leading to full-blown RA.
There are a few other possible factors that influence your chances of developing Ra, such as your birth weight. Heavier babies (over 10 lbs at birth) seem to have a higher incidence of RA than do those with birth weights of between 5 lbs and 9 lbs. There are even those who question whether being breastfed as an infant affects your future chances of developing RA, and others who are researching whether breastfeeding a child for a certain length of time will offer a woman future protection from RA symptoms.
Where you are born may also have an influence on your chances of developing RA. Certain areas of the US and Canada have much higher rates of RA than other areas. At this time, however, it is not known whether this is due to ancestry, since ethnic groups tended to settle in clusters, or factors such as water quality or diet.
While obesity does seem to have a correlation to rates of RA, it is not yet known whether obesity causes RA, or whether both RA and obesity are caused by a third factor that is as yet unidentified.
The good news in all of this is that individuals who drink alcohol 3 to 4 times a week (in moderation, of course) seem to have less RA, and of those who do have RA, the symptoms are less sever in those who drink in moderation.