estrogen concentrations. However, alcoholism is known to have negative effect on bone.10) In women, both age of menarche and postmenopausal period had negative association with BMD, and total period of HRT (estrogen regimen) had a positive association with BMD. These findings accord with known positive effects of estrogen on bone. The present study differs from previous reports that investigated the association between food intake and bone health in that it is the first report that examined BMD in a large sample of adults in Korea. It also deals with food intake frequency of a variety of food groups and food items that properly reflects people’s diet. Because dietary habits vary widely, studies implemented on specific populations can be very useful. In addition, this study collected extensive information on other factors known to affect bone health, such as BMI, physical activity, smoking, alcohol drinking, diseases like hypertension, rheumatoid arthritis, thyroid disease, cerebrovascular accident, coronary artery diseases, diabetes, supplements of vitamin or minerals, menarche, menopause, and estrogen use, thus enabling the association between BMD and food consumption to be adjusted for the potential confounding effects of these variables. However, the main limitation of this study is that the design was cross-sectional so that only associations rather than causal relations between food and BMD can be inferred. The other limitation is that food frequency may not represent the accurate amount of food consumed. Therefore, further investigations with quantitative analysis of food and nutrient consumption and long- term follow-up are warranted. CONFLICT OF INTEREST No potential conflict of interest relevant to this article was reported. REFERENCES Korean J Fam Med 1. Kanis JA. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: synopsis of a WHO report. WHO Study Group. Osteoporos Int 1994;4: Eui-Hyun Yoon, et al: BMD and Food-frequency 368-81. 2. Tucker KL, Hannan MT, Chen H, Cupples LA, Wilson PW, Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. Am J Clin Nutr 1999;69:727-36. 3. Mitchell BD, Kammerer CM, Schneider JL, Perez R, Bauer RL. Genetic and environmental determinants of bone mineral density in Mexican Americans: results from the San Antonio Family Osteoporosis Study. Bone 2003;33:839-46. 4. Cummings SR , Kelsey JL, Nevitt MC, O’Dowd K J. Epidemiology of osteoporosis and osteoporotic fractures. Epidemiol Rev 1985;7:178-208. 5. Livshits G, Deng HW, Nguyen TV, Yakovenko K, Recker RR, Eisman JA. Genetics of bone mineral density: evidence for a major pleiotropic effect from an intercontinental study. J Bone Miner Res 2004;19:914-23. 6. Eisman JA. Genetics of osteoporosis. Endocr Rev 1999;20: 788-804. 7. Nelson ME, Fiatarone MA, Morganti CM, Trice I, Greenberg RA, Evans WJ. Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. A randomized controlled trial. JAMA 1994;272:1909-14. 8. Seeman E, Melton LJ 3rd, O’Fallon WM, Riggs BL. Risk factors for spinal osteoporosis in men. Am J Med 1983;75: 977-83. 9. Kiel DP, Zhang Y, Hannan MT, Anderson JJ, Baron JA, Felson DT. The effect of smoking at different life stages on bone mineral density in elderly men and women. Osteoporos Int 1996;6:240-8. 10. Schapira D. Alcohol abuse and osteoporosis. Semin Arthritis Rheum 1990;19:371-6. 11. Felson DT, Zhang Y, Hannan MT, Kiel DP, Wilson PW, Anderson JJ. The effect of postmenopausal estrogen therapy on bone density in elderly women. N Engl J Med 1993;329: 1141-6. 12. Matkovic V, Fontana D, Tominac C, Goel P, Chesnut CH 3rd. Factors that influence peak bone mass formation: a study of calcium balance and the inheritance of bone mass in adolescent females. Am J Clin Nutr 1990;52:878-88. 13. Tranquilli AL, Lucino E, Garzetti GG, Romanini C. Calcium, phosphorus and magnesium intakes correlate with bone Vol. 33, No. 5 Sep 2012 | 293