Drinking milk may slow osteoarthritis' progression

Women who regularly drink fat-free or low-fat milk could delay the progression of osteoarthritis (OA) of the knee, according to research published in the Arthritis Care & Research journal.

The study also reveals that eating cheese caused the condition to progress in females, whereas consuming yogurt has no measurable impact. OA is a common, degenerative joint disease that can cause severe pain and swelling in the hands, knees or hips.

“Dietary factors were under-researched in OA progression. It is of great public health and clinical significance to examine the role of diet in OA progression,” says Dr Bing Lu, Assistant Professor of Medicine, Brigham and Women’s Hospital in Boston, Massachusetts. Dr Lu and colleagues wrote the article published online.

Dr Lu says the key finding in the study, which is the largest to investigate the effect of dairy intake on the progression of knee OA, is that increased milk consumption is associated with slower progression of joint space narrowing in women with OA. Progression was also slower in men who drank seven or more glasses of milk per week.

More than 2,100 participants – 888 men and 1,260 women – with knee OA were involved in the new research. Scientists discovered that as the intake of milk increases, the joint space width in women decreases.

Cheese increases acceleration of joint damage

On the other hand, eating more than seven servings of cheese a week can worsen knee OA. Researchers suggest this might be because of its high level of saturated fatty acids. Increased consumption of saturated fatty acids has been linked to bone marrow lesions, which in turn predict knee OA progression.

Calcium and OA progression in women vs men

Researchers suspect dietary calcium might be a factor that links milk consumption with reduced knee OA progression. The highest quartile of dietary calcium intake among the women in the study was associated with significantly less joint space narrowing.

Calcium might also explain some of the sex difference. The average dietary calcium intake of the women participants was 647 mg/day, whereas it was 715 mg/day among the men. “If dietary calcium is a possible mediation factor linking milk consumption and knee OA progression, women may be more sensitive to its effect than men. However the gender differences in the relationship between milk consumption and OA progression are not completely understood,” say the authors.

“Sex differences have been noted in the prevalence, incidence, and severity of OA for many years. Faber and colleagues found cartilage thickness of the distal femur to be less in women than in men. Other evidence suggests exogenous oestrogen exerts a protective effect on cartilage and bone turnover,” Dr Lu says.

Dr Lu concludes by saying: “A healthy diet, including frequently drinking fat-free or low-fat milk, would be beneficial to your knees and general health.”

Further links:
Brighamandwomens.org
Webmd.com
Medscape.com