Effect of periodic abstinence from dairy products for approximately half of the year on bone health in adults following the Christian Orthodox Church fasting rules for decades.

Unlabelled: Christian Orthodox Church (COC) fasting is characterized by periodic abstinence from animal foods (including dairy products). We found that, despite this, older individuals adhering to COC fasting for decades did not differ in bone mineral density, bone mineral content, or prevalence of osteoporosis at five sites from non-fasting controls.

Purpose: The present observational study investigated whether adherence to COC fasting, characterized by periodic abstinence from animal foods (including dairy products), affects bone health and the prevalence of osteoporosis in older individuals.

Methods: Participants were 200 men and women, of whom 100 had been following the fasting rules of the COC for a median of 31 years and 100 were non-fasters, all aged 50 to 78 years. Participants underwent measurements of bone mineral density (BMD) and bone mineral content (BMC) at the lumbar spine, right hip, left hip, right femoral neck, and left femoral neck; completed a 3-day food intake record and food frequency questionnaire; and provided blood samples for biochemical measurements.

Results: Fasters did not differ from non-fasters in demographic characteristics, anthropometric measures, BMD, BMC, or prevalence of osteopenia or osteoporosis at any of the five sites measured (P > 0.05). Fasters had lower daily calcium intake than non-fasters (median 532 vs 659 mg, P = 0.010), daily protein intake (0.67 vs 0.71 g/kg, P = 0.028), and consumption of dairy and soy products (10.3 vs 15.3 servings per week, P < 0.001). Groups did not differ in serum calcium, vitamin D, or urea concentrations.

Conclusions: Despite lower calcium intake and lower consumption of dairy and soy products, older individuals adhering to COC fasting did not differ in BMD, BMC, or prevalence of osteoporosis from controls. Thus, periodic abstinence from dairy and, generally, animal products does not seem to compromise bone health in older individuals.