Our bones are constantly in a state of adding minerals and being broken down. The interaction between the two is necessary for our bones to be healthy. Decreased bone density occurs when the rate of breakdown is faster than the rate of building bone by adding minerals. The conditions when the bone becomes more fragile or vulnerable are known as osteopenia and osteoporosis (osteoporosis is more serious or severe).
Osteoporosis has no single cause; it is related to a complex series of hormonal interactions that regulate bone formation and reabsorption. A number of different hormone levels, including estrogen and testosterone, are important in mineral deposition and activity of osteoblasts, the cells which create new bone.
Calcium, along with a long list of other minerals and vitamins (including Vitamin D) are important for maintaining healthy bone density.
• Coffee and caffeine interfere with the absorption of minerals and increase the excretion of several vital minerals, including calcium, potassium, magnesium and iron. (Bergman, et al, 1990)
Coffee and Bone Density
• High coffee intake is associated with an increased risk of lower bone density in older women. (Korpelaninen, et al, 2003); (Barrett-Connor, et al, 1994); (Hernandez-Avila, et al, 1993)
• Women with high caffeine intakes experience higher rates of bone loss than those with low intakes. (Mikuls, et al, 2002); (Rapuri, et al, 2001)
• Bone loss associated with caffeine consumption is especially pronounced in women who do not consume adequate calcium. (Harris and Dawson-Hughes, 1994)
• It is difficult for older women to compensate for the calcium loss due to caffeine. (Massey and Whiting, 1993)
Coffee and Increased Metabolic Acidity
• Consumption of acidic foods including coffee increases the leaching of minerals from the bone due to overall increased metabolic acidity. Minerals appear to have a buffering effect on the bloodstream and are subsequently leached from bone to realkinalize the blood when pH levels have shifted too far into acidity. (Kynast-Gales and Massey, 1994)
• Excess acidity has been associated with negative calcium balance and increased excretion of calcium. (Massey and Whiting, 1993)
Coffee, Homocysteine and Osteoporosis
• Coffee drinking significantly increases serum levels of the amino acid homocysteine. This negative effect of coffee drinking occurs with caffeinated, decaffeinated, filtered and unfiltered coffee. It is noted within hours of coffee consumption. (Verhoef, et al, 2002); (Urgert, et al, 2000); (Grubben, et al, 2000)
• High homocysteine levels are a significant risk factor for developing osteoporotic fractures. (van Meurs, et al, 2004); (McLean, et al, 2004)
References (by alphabetical order)
Barrett-Connor, E., Chang, J.C. and Edelstein, S.L. 1994. Coffee-associated osteoporosis offset by daily milk consumption. The Rancho Bernardo Study. JAMA. 271(4). 280-3.
Bergman, E.A., Massey, L.K., Wise, K.J. and Sherrard, D.J. 1990. Effects of dietary caffeine on renal handling of minerals in adult women. Life Sciences. 47(6):557-64.
Grubben, M.J., Boers, G.H., Blom, H.J., Broekhuizen, R., de Jong, R., van Rijt, L., de Ruijter, E., Swinkels, D.W., Nagengast, F.M. and Katan, M.B. 2000. Unfiltered coffee increases plasma homocysteine concentrations in healthy volunteers: a randomized trial. American Journal of Clinical Nutrition. 71(2):480-4.
Harris, S.S. and Dawson-Hughes, B. 1994. Caffeine and bone loss in healthy postmenopausal women. American Journal of Clinical Nutrition. 60(4):573-8.
Hernandez-Avila, M., Stampferm M,J,, Ravnikar, V.A., Willett, W.C., Schiff, I., Francis, M., Longcope, C. and McKinlay, S.M. 1993. Caffeine and other predictors of bone density among pre- and perimenopausal women. Epidemiology. 4(2):128-34.
Korpelainen, R., Korpelainen, J., Heikkinen, J., Vaananen, K. and Keinanen-Kiukaanniemi, S. 2003. Lifestyle factors are associated with osteoporosis in lean women but not in normal and overweight women: a population-based cohort study of 1222 women. Osteoporosis International. 14(1):34-43.
Kynast-Gales, S.A. and Massey, L.K. 1994. Effect of caffeine on circadian excretion of urinary calcium and magnesium. Journal of the American College of Nutrition. 13(5):467-72.
Massey, L.K. and Whiting, S.J. 1993. Caffeine, urinary calcium, calcium metabolism and bone. Journal of Nutrition. 123(9):1611-4.
McLean, R.R., Jacques, P.F., Selhub, J., Tucker, K.L., Samelson, E.J., Broe, K.E., Hannan, M.T., Cupples, L.A. and Kiel, D.P. 2004. Homocysteine as a predictive factor for hip fracture in older persons. New England Journal of Medicine. 350(20):2042-9.
Mikuls, T.R., Cerhan, J.R., Criswell, L.A., Merlino, L., Mudano, A.S., Burma, M., Folsom, A.R. and Saag, K.G. 2002. Coffee, tea, and caffeine consumption and risk of rheumatoid arthritis: results from the Iowa Women's Health Study. Arthritis and Rheumatism. 46(1):83-91.
Rapuri, P.B., Gallagher, J.C., Kinyamu, H.K. and Ryschon, K.L. 2001. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes. American Journal of Clinical Nutrition. 74(5):694-700.
Urgert, R., van Vliet, T., Zock, P.L. and Katan, M.B. 2000. Heavy coffee consumption and plasma homocysteine: a randomized controlled trial in healthy volunteers. American Journal of Clinical Nutrition. 72(5):1107-10.
van Meurs, J.B., Dhonukshe-Rutten, R.A., Pluijm, S.M., van der Klift, M., de Jonge, R., Lindemans, J., de Groot, L.C., Hofman, A., Witteman, J.C., van Leeuwen, J.P., Breteler, M.M., Lips, P., Pols, H.A. and Uitterlinden, A.G. 2004. Homocysteine levels and the risk of osteoporotic fracture. New England Journal of Medicine. 350(20):2033-41.
Verhoef, P., Pasman, W.J., Van Vliet, T., Urgert, R. and Katan, M.B. 2002. Contribution of caffeine to the homocysteine-raising effect of coffee: a randomized controlled trial in humans. American Journal of Clinical Nutrition. 76(6):1244-8.