Vinegar is not useful for treating arthritis, according to Healthline. Although apple cider vinegar is proposed as a remedy for arthritis pain, it does not contain any nutrients that would have that effect.
Some people believe that the beta carotene in apple cider vinegar attacks free radicals in the body, which damage the immune system, explains the Arthritis Foundation. However, this type of vinegar contains only trace amounts of beta carotene. Carrots have large amounts of beta carotene, and their consumption does not improve symptoms of arthritis.
An alternative theory is that apple cider vinegar dissolves acid crystals that cause arthritis, the Arthritis Foundation says. However, gout, a form of arthritis that produces uric acid crystals, is unaffected by vinegar.