A glass of milk a day may help keep arthritis away, according to a new study.
The new research showed that women who drank up to seven glasses of low-fat or fat-free milk every week experienced significantly slower joint narrowing in their knees, which is one of the hallmarks of osteoarthritis. Osteoarthritis is a common degenerative joint disease that worsens with age or repetitive motion and results in swollen, painful joints – usually in the hands, hips or knees. Osteoarthritis, which affects nearly a third of all people over age 65, occurs when the cartilage protecting a joint degenerates and the joint space narrows, bringing the bones into closer contact and resulting in bony overgrowth and stiffness.
Researchers gathered dietary data and measured joint space width in 2,148 men and women with knee osteoarthritis. Over the course of the four-year study, joint space decreased by 0.38 mm for women who drank no milk, compared to 0.26 mm for women who drank seven or more glasses a week. In general, the more milk women drank, up to seven glasses, the less joint space narrowing they experienced. One glass is equivalent to 8 ounces of milk.
The results stayed consistent even when the study’s authors adjusted for disease severity, body mass index (BMI) and other dietary considerations. However, while the study observed a correlation between milk and arthritis, it doesn’t necessarily prove that milk was responsible for the joint improvement. The researchers did not find a similar benefit between milk drinking and joint protection in men, perhaps because estrogen may impact how sensitive women are to calcium uptake from the diet.
Researchers also looked at other sources of dairy, which did not show the same benefits as milk. Cheese appeared to worsen joint space narrowing, and yogurt had no effect.