3. Dairy products. Milk, cheese, and other dairy products have been known to irritate arthritic conditions, according to The Physicians Committee for Responsible Medicine. “Dairy foods are one of the principle offenders, and the problem is the dairy protein, rather than the fat, so skim products are as much a problem as whole milk,” the Committee says. “Once the offending food is eliminated completely, improvement usually comes within a few weeks.” Mayo Clinic rheumatologist Dr. Clement Michet told Everyday Health the body can create antibodies against what it thinks is a harmful substance, in this case the dairy proteins. Those antibodies then attack not only the milk but also certain portions of the body itself, he noted. Doctors suggest soy, rice, or almond milk as dairy alternatives for those suffering from arthritis.