There is a clear link that as countries adopt a westernized life style, that's when we really start to see more or to a new disease developing. The biggest risk factor for developing pretty much any of these diseases is actually genetic. So if you're not particularly genetically predisposed to getting an autommune disease, any of the triggers that might set offer a disease in some one else will almost certainly have no effect on you at all. It would be a huge over simplification to just point our fingers just at diet, because we know that things like pollution and smoking and obesity and stress also undoubtedly contributing to this.