Dairy Products are not Necessary for Bone Health ----- and may even be Detrimental

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The calcium paradox refers to the unexpected observation that osteoporosis and hip fracture rates are highest in the countries with the highest calcium consumption. Many studies have concluded that …

The calcium paradox refers to the unexpected observation that osteoporosis and hip fracture rates are highest in the countries with the highest calcium consumption. Many studies have concluded that high calcium intake, especially in the form of dairy products, is not beneficial to bone health. A high animal protein diet may actually be detrimental to bone health, and dairy consumption is not a necessary component of a nutritious diet. High fruit and vegetable consumption, minimal animal proteins, and regular exercise may be the best recommendation for healthy bones.

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  • I agree 100% - dairy is NOT needed to maintain/obtain a healthy diet. There are other sources of calcium that don't include milk, like sesame seeds, almonds, soybeans, parsley, collard greens, and garbanzo beans. Nicole I would recommend reading 'The Kind Diet' by Alicia Silverstone, it's really informative and interesting. Your presentation looks great!
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  • 1. Dairy Products are not Necessary for Bone Health ----- and may even be Detrimental Kristen Nilsson Farley In conjunction with Melissa Nickel Nutrition 577 December 2009
  • 2. Abstract
    • The calcium paradox refers to the unexpected observation that osteoporosis and hip fracture rates are highest in the countries with the highest calcium consumption. Many studies have concluded that high calcium intake, especially in the form of dairy products, is not beneficial to bone health. A high animal protein diet may actually be detrimental to bone health, and dairy consumption is not a necessary component of a nutritious diet. High fruit and vegetable consumption, minimal animal proteins, and regular exercise may be the best recommendation for healthy bones.
    • This presentation is intended to be viewed in conjunction with Melissa Nickel’s presentation, which argues for the importance of dairy consumption in a healthy diet.
  • 3. Learning Objectives
    • After viewing this presentation, the reader will:
        • Understand what is meant by “the calcium paradox”
        • Appreciate the importance of a diet rich in calcium-rich vegetables to ensure adequate calcium consumption and its bone-protective qualities.
        • Be aware of the controversy surrounding the relationship between animal protein consumption and bone health.
        • Recognize that many nutrition professionals believe that dairy consumption is not necessary for bone health, and may, in fact, be detrimental to the bones and other health indicators.
  • 4. Harvard School of Public Health, on the Consumption of Dairy Products (2005)
    • “ The recommendation to drink three glasses of low-fat milk or eat three servings of other dairy products per day to prevent osteoporosis is another step in the wrong direction. … Three glasses of low-fat milk add more than 300 calories a day. This is a real issue for the millions of Americans who are trying to control their weight. What's more, millions of Americans are lactose intolerant, and even small amounts of milk or dairy products give them stomachaches, gas, or other problems. This recommendation ignores the lack of evidence for a link between consumption of dairy products and prevention of osteoporosis. It also ignores the possible increases in risk of ovarian cancer and prostate cancer associated with dairy products.”
  • 5. The Calcium Paradox
    • Hip fracture rates are highest in countries with high calcium intake and lowest where calcium intake is lower (Lanou, 2009; FAO/WHO, 1998)
    • American women >50 yo have one of the highest rates of hip fractures in the world (Frassetto et al., 2000).
    • According to the WHO: “the adverse effect of protein, in particular animal protein, might outweigh the positive effect of calcium intake on calcium balance” (FAO/WHO, 1998).
  • 6. Summary of Some of the Relevant Studies
    • Many studies have attempted to evaluate the relationship between dairy consumption and risk of fractures, particularly of the hip. Results have been inconsistent and often conflicting. A summary of some of the many studies showing no relationship between dairy consumption and bone health is presented on the next several slides.
    • Harvard Nurses’ Health Study (Feskanich et al., 1997)
      • >75,000 women, >12 year prospective study
      • No protective effect of increased milk consumption on fracture risk.
    • Swedish Mammography Screening Cohort (Michaelsson et al., 2003)
      • >60,000 women, >11 year prospective study
      • Concluded that dietary calcium in middle-aged and elderly Caucasian women does not substantially influence osteoporotic fracture risk.
  • 7. Relevant Studies (cont.)
    • Meta-analyses
      • Concluded that there is no reduction in risk of hip fracture with higher intakes of milk, dairy, or total dietary calcium.
      • In fact, Bischoff-Ferrarri (2007) found a significantly greater risk of hip fractures with calcium supplementation.
      • Kanis et al. (2005) concluded that self-reported low intake of milk is not associated with any marked increase in fracture risk. The use of this risk indicator is of little or no value in case-finding strategies.
  • 8. Relevant Studies (cont.)
    • Studies of teens and children
    • Neither milk nor calcium intake >500 mg/day shows a beneficial effect on children’s bones (Lloyd et al., 2000; Lanou et al., 2005; Winzenberg et al., 2006).
    • Calcium intake among girls 12-18 was not associated with hip bone density at age 20. Hip bone density did, however, reflect physical activity levels during the teenage years (Lloyd et al., 2000).
    • Meta-analysis of 37 studies showed little or no relationship between dairy or dietary calcium intake and measures of bone health in adolescents (Lanou et al, 2005)
    • Even a doubling of calcium intake from milk for a year showed no difference in bone health among white, adolescent girls (Chan et al., 1995).
  • 9. Protein and Bone Health
    • Fracture incidence is associated with high protein intake (Abelow et al., 1992). High protein consumption increases calcium loss in the urine (Barzel and Massey, 1998).
    • In an analysis of 34 studies from 16 countries, a strong correlation was seen between animal protein intake and bone fracture rate (Abelow, 1992)
    • Animal protein, unlike plant protein, increases the acidic load in the body (Wachsman and Bernstein, 1968). The body pulls calcium from the bones in order to fight the acidic environment.
    • In a 7-year study of over 1000 women ≥ 65 yo, the women with the highest rate of animal protein to plant protein had 3.7x more bone fractures than the women with the lowest ratio (Sellmeyer et al., 2001)
  • 10. There is a dramatic decrease in bone fracture incidence when the ratio of vegetable to animal protein increases (Frassetto, 2000).
  • 11. Calcium and Bone Health
    • A higher consumption of calcium was associated with a higher risk of bone fracture in a comparison study of 10 countries (Hegsted, 1986).
    • Hip fractures are more frequent in populations where dairy products are commonly consumed and calcium intakes are relatively high (Hegsted, 1986).
  • 12. Calcium Availability from Different Sources
    • Calcium is more highly absorbed from beans and most greens than from milk. 40-64% of calcium from beans and greens is absorbed compared to 32% from milk (Lanou, 2009).
    • Fortified cereals, juices, soy milk, rice milk have calcium that is absorbed at comparable levels to dairy calcium (approx 28-36% for those sources) (Lanou, 2009).
  • 13. Calcium availability from various foods The amount of each food is the amount needed to absorb approximately 100 mg Ca. (Lanou, 2009).
  • 14. Other risks possibly associated with dairy consumption
    • Although is is beyond the scope of this presentation, it is worth pointing out the relationship between dairy consumption and other health concerns (cited in Lanou, 2009).
      • Prostate cancer
      • Type 1 Diabetes
      • Ear Infections
      • Allergies
      • Increase in saturated fat, total fat, cholesterol consumption which can lead to increases in obesity, heart disease, cancers, diabetes, etc.
      • Reliance on dairy as a protein and calcium source displaces more healthful plant sources which are high in fiber, antioxidants, and phytochemicals
      • Digestive difficulties; especially from Lactose
      • Concerns about contaminants such as hormones, antibiotics, pesticides, steroids
      • Preferences and beliefs related to production practices
  • 15. Recommendations for Bone Health
    • Achievable levels of exercise and fitness have a favorable effect on bone. Lloyd et al (2004) concluded that exercise is the predominant lifestyle determinant of bone strength.
    • WHO recommendations (FAO/WHO, 1998)
      • Increase physical activity
      • Reduce sodium intake
      • Reduce consumption of animal protein
      • Increase consumption of fruits and vegetables
      • Moderate sun exposure to promote Vitamin D production
  • 16. Conclusions
    • There are adequate ways to ensure bone health without consuming diary products.
    • For those who are willing to put in the effort to eat a nutritious diet, I would not advocate dairy products to someone who does not enjoy them. However, one must take care to consume adequate dietary protein and calcium, abundant fruits and vegetables, minimize animal protein, and get regular exercise and responsible sun exposure.
    • When the alternative is high-sugar drinks and a nutrient-poor diet, low-fat dairy should be considered an important source of calcium and protein.
  • 17. Bibliography
    • Abelow BJ, Holford TR, Insogna KL. Cross-cultural association between dietary animal protein and hip fracture: a hypothesis. Calcif Tissue Int 1992;50:14-18.
    • Barzel US, Massey LK. Excess dietary protein can adversely affect bone. J Nutr 1998;128;1051-3. 
    • Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, et al. Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials. Am J Clin Nutr 2007;86:1780-90. 
    • Chan GM, Hoffman K, McMurry M. Effects of dairy products on bone and body composition in pubertal girls. J Pediatr 1995;126:551-6.
    • Feskanich D, Willett WC, Stampfer MJ, Colditz GA. Milk, dietary calcium, and bone fractures in women: a 12-year prospective study. Am J Public Health 1997;87:992-7.
    • Frassetto LA, Todd KM, Morris RC, Jr., et al. Worldwide incidence of hip fracture in elderly women: relation to consumption of animal and vegetable foods. J Gerontology 2000;55: M585-M592.
    • Harvard School of Public Health, The Nutrition Source; Food Pyramids: What Should You Really Eat?; Harvard School of Public Health, 2005 http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/pyramid-full-story/index.html (accessed 11/28/09) 
    • Hegsted DM. Calcium and osteoporosis J Nutr 1986;116:2316-2319.
  • 18.
    • Kanis JA, Johannson H, Oden A, et al. A meta-analysis of milk intake and fracture risk; low utility for case finding. Osteoporos Int 2005;16:799-804. 
    • Lanou, AJ. Should diary be recommended as part of a healthy vegetarian diet? Counterpoint. Am J Clin Nutr 2009;89(suppl):1638S-42S.
    • Lanou AJ, Berkow SE, Barnard ND, Calcium, dairy products, and bone health in children and young adults: a reevaluation of the evidence. Pediatrics 2005;115:736-43.
    • Lloyd T, Chinchilli VM, Johnson-Rollings N, Kieselhorst K, Eggli DF, Marcus R. Adult female hip bone density reflects teenage sports-exercise patterns but not teenage calcium intake. Pediatrics 2000;106:40-4.
    • Michaelsson K, Melhus H, Bellocco R, Wolk A. Dietary calcium and vitamin D in relation to osteoporotic fracture risk. Bone 2003;32:694-703.
    • Report of a Joint FAO/WHO Expert Consultation. Human vitamin and mineral requirements. September 1998, Bangkok, Thailand. ftp.fao.org/es/esn/nutrition/Vitrni/vitrni.html (accessed 11/28.09)
    • Sellmeyer DE, Stone KL, Sebastian A, et al., A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Am J Clin Nutr 2001;73:118-122.
    • Waschman A, Bernstein DS. Diet and osteoporosis. Lancet 1968:958-959.
    • Winzenberg T, Shaw K, Fryer J, Jones G. Effects of calcium supplementation on bone density in healthy children: meta-analysis of randomized controlled trials. BMJ 2006;333:775.