Water is crucial in any illness. Most people I talk to do not drink enough water and are even dehydrated. Think about the things we drink: coffee, soda, iced tea, alcohol. These drinks do not add any water into the system, but rather dehydrate the body even further.
Here is the reason that people with Arthritis
need more water. Osteoarthritis begins when the cartilage starts to wear down. Cartilage is composed of about two-thirds water. So not enough water in the system= cartilage wears out.
I suggest that your friend drink at least half his or her body weight in water each day. So, weight at 150lbs than drink 75 ounces. Start each day with a big glass and end each day with a glass.
Hope this helps.