A glass of milk a day may delay knee osteoarthritis in women

A degenerative disease causing pain and swelling of the knee joints, knee osteoarthritis currently is difficult to cure. But researchers say drinking milk every day has been linked to reduced progression of the disease.

The researchers say while their findings show that women who regularly drank fat-free or low-fat milk experienced delayed progression of knee osteoarthritis (OA), those who ate cheese actually experienced an increase in progression of the disease. They also note that their findings are not applicable to men, and that yogurt did not affect OA progression.

Osteo Arthritis is characterized by degeneration of the cartilage and its underlying bone in a joint, is believed to result from "mechanical and molecular events in the affected joint. However, the actual causes of the disease are unknown. Treatment for the condition aims to relieve symptoms and improve function, which can include physical therapy, weight control and medications.

The study authors say milk consumption has been acknowledged as playing an important role in bone health, but until now, its role in the progression of knee OA has been unknown. The researchers found that, in women, as milk intake increased (from none to less than 3, 4-6, and more than 7 glasses per week), the joint space width decreased (by 0.38 mm, 0.29 mm and 0.26 mm, respectively). Though obesity has been cited as a risk factor for knee OA, the researchers say their results remained, even after adjusting for body mass index.

Additionally, they say there was no association between milk consumption and joint space width decreases in men. When asked why their study revealed that women who consumed cheese showed increased progression of OA, researchers told that the high saturated fat acids in cheese could be to blame. There is one recent study reported that increased consumption of saturated fatty acids was associated with an increased incidence of bone marrow lesions, which may predict knee OA progression.

With the aging population and increase in life expectancy, there is an urgent need for effective methods to manage OA. The study by Lu et al. provides the first evidence that increasing fat-free or low-fat milk consumption may slow the progression of OA among women who are particularly burdened by OA of the knee, which can lead to functional disability.