In a non-dairy nutshell (you see what I did there), he suggested that a woman with osteoporosis avoid dairy because "dairy can remove the calcium from your bones"... Dairy is commonly avoided by those following a Paleo lifestyle because it's not considered an appropriate food in-keeping with pre-agricultural diets.
Now, I have to say, I like Pete. He seems like a great guy, and he has been nice enough to mention me and my story on his Facebook page. He has also done a great job of encouraging thousands to eat more healthily (as you know I am not averse to Paleo as a compendium of foods for a healthy diet, in fact, I think it provides an easy conceptual structure that people can understand and apply).
But I disagree with him on this point for several reasons:
1. Dairy does not strip calcium from bones
2. Dairy is not 'unhealthy' in an absolute sense
3. It is ethically dubious to provide what could be considered medical advice if you are not a qualified and registered practitioner.
The issue is primarily when someone is overzealous about one 'right way' to eat. We need to recognise that there is a spectrum of diet and people respond differently to different 'diets' depending on their ethnicity/genetic factors, activity, metabolic state, and other factors such as allergy or intolerance to foods. I stated in my latest book The Carbohydrate Appropriate Diet that if dairy works for you and you tolerate it well, then there is no good reason to ditch it from the diet.
I have also become more and more concerned lately with medical and other health advice for conditions being provided by people outside of their scope of education, registration and skill-set. On the whole, I think the info that Pete puts out is awesome but when diets, supplements, herbs or medications are being either included or excluded to treat a condition, then it is prudent to take advice from someone qualified and registered. Others should refrain from giving medical advice in any forum that could be misconstrued and that is without an appropriate context (a clinical assessment especially).
Extra for geeks...
Does dairy strip calcium from bones?
A quick look at the empirical evidence suggests that dairy does not strip calcium from bones, but in fact aids bone mineral density:
“bone accretion is improved up to 10% when dairy products are used as a source of supplemental calcium in adolescent girls” 1
Hypoenergetic diets higher in dairy foods, dietary calcium, and protein with daily exercise, favorably affected important bone health biomarkers vs. diets with less of these bone-supporting nutrients.2
Consuming ≥ 2 servings/day of dairy (versus less) was associated with significantly higher mean BMC and BA. Higher intakes of meats/other proteins (≥ 4 servings per/day) were also associated with higher mean BMC and BA values. Children with higher intakes of both dairy and meats/other proteins had the highest adjusted BMC (3090.1 g), and children consuming less of each had the lowest BMC (2740.2 g).3
Alcohol or smoking had a significant negative effect on bone density, whereas adequate dairy intake (>4 servings per day) had a favorable effect in Wisconsin adolescents.4
A reduced-energy diet supplying 1.4 g·kg−1·d−1 protein and 3 dairy servings increased urinary calcium excretion but provided improved calcium intake and attenuated bone loss over 4 mo of weight loss and 8 additional mo of weight maintenance.5
The data support the hypothesis that adequate calcium intake through milk and milk products in childhood and adolescence is a decisive marker for attaining maximum bone mass (peak adult bone mass) and for the prevention of osteoporosis.6
Cross-sectional results indicated that higher dairy product consumption is associated with greater hip BMD in men, but not in women. Calcium supplementation protected both men and women from bone loss in the longitudinal study of whites.7
[Meta-analysis] “Increased dietary calcium/dairy products, with and without vitamin D, significantly increases total body and lumbar spine BMC in children with low base-line intakes.”8
Dairy foods varied widely in their content of nutrients known to affect calcium excretion and skeletal mass. Foods such as milk and yogurt are likely to be beneficial; others, such as cottage cheese, may adversely affect bone health. Of the few stronger-evidence studies of dairy foods and bone health, most had outcomes that were not significant. However, white women <30 y old are most likely to benefit. There are too few studies in males and minority ethnic groups to determine whether dairy foods promote bone health in most of the US population.9
Young girls whose dietary calcium intake was provided primarily by dairy products at or above the recommended dietary allowances had an increased rate of bone mineralization.10
Dairy and health
There appears to be a rising incidence of milk protein intolerance and allergy11 and I have often erred towards eliminating dairy early in the process of fat-loss because of its highly insulinergic nature12 and to help determine if the client does, in fact, have any degree of dairy protein intolerance or allergy.
The evidence though for the absolute avoidance of dairy by most people is sparse. In fact, in an adequate protein diet, a moderate dairy intake retains lean mass during dieting more effectively than the same protein with a lower dairy intake (and high protein, high dairy intake increases fat-loss).13 People lose more fat when supplemented with calcium, and more again when the same amount of calcium is provided from a diary containing diet.14, 15 It is likely to exert a synergistic effect along with dairy proteins (especially the BCAAs found in dairy in abundance) and angiotensin-converting enzyme inhibitors, to attenuate adiposity.16
Systematic reviews and meta-analyses of the evidence have concluded that increased dairy consumption without energy restriction or in long-term studies might not lead to a significant change in weight or body composition, but the inclusion of dairy in energy-restricted weight-loss diets significantly reduces weight, body-fat and improves lean-mass.17, 18 There has also been demonstrated an inverse association between the intake of dairy products with type-2 diabetes19, 20 and high-dairy consumption improves insulin resistance without negatively impacting bodyweight or cardiometabolic markers.21
1. Kerstetter JE. Do Dairy Products Improve Bone Density in Adolescent Girls? Nutrition reviews. 1995;53(11):328-32.
2. Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Diets Higher in Dairy Foods and Dietary Protein Support Bone Health during Diet- and Exercise-Induced Weight Loss in Overweight and Obese Premenopausal Women. The Journal of Clinical Endocrinology & Metabolism. 2011;97(1):251-60.
3. Moore LL, Bradlee ML, Gao D, Singer MR. Effects of Average Childhood Dairy Intake on Adolescent Bone Health. The Journal of Pediatrics. 2008;153(5):667-73.
4. Korkor AB, Eastwood D, Bretzmann C. Effects of gender, alcohol, smoking, and dairy consumption on bone mass in Wisconsin adolescents. WMJ. 2009;108(4):181-8.
5. Thorpe MP, Jacobson EH, Layman DK, He X, Kris-Etherton PM, Evans EM. A Diet High in Protein, Dairy, and Calcium Attenuates Bone Loss over Twelve Months of Weight Loss and Maintenance Relative to a Conventional High-Carbohydrate Diet in Adults. The Journal of Nutrition. 2008;138(6):1096-100.
6. Renner E. Dairy Calcium, Bone Metabolism, and Prevention of Osteoporosis1. Journal of Dairy Science. 1994;77(12):3498-505.
7. McCabe LD, Martin BR, McCabe GP, Johnston CC, Weaver CM, Peacock M. Dairy intakes affect bone density in the elderly. The American Journal of Clinical Nutrition. 2004;80(4):1066-74.
8. Huncharek M, Muscat J, Kupelnick B. Impact of dairy products and dietary calcium on bone-mineral content in children: Results of a meta-analysis. Bone. 2008;43(2):312-21.
9. Weinsier RL, Krumdieck CL. Dairy foods and bone health: examination of the evidence. The American Journal of Clinical Nutrition. 2000;72(3):681-9.
10. Chan GM, Hoffman K, McMurry M. Effects of dairy products on bone and body composition in pubertal girls. The Journal of Pediatrics. 1995;126(4):551-6.
11. Rona RJ, Keil T, Summers C, Gislason D, Zuidmeer L, Sodergren E, et al. The prevalence of food allergy: A meta-analysis. Journal of Allergy and Clinical Immunology. 2007;120(3):638-46.
12. Holt S, Miller J, Petocz P. An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods. The American Journal of Clinical Nutrition. 1997;66(5):1264-76.
13. Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women. J Nutr. 2011;141(9):1626-34.
14. Zemel MB, Thompson W, Milstead A, Morris K, Campbell P. Calcium and dairy acceleration of weight and fat loss during energy restriction in obese adults. Obes Res. 2004;12(4):582-90.
15. Zemel MB, Richards J, Milstead A, Campbell P. Effects of calcium and dairy on body composition and weight loss in African-American adults. Obes Res. 2005;13(7):1218-25.
16. Zemel MB. Role of calcium and dairy products in energy partitioning and weight management. Am J Clin Nutr. 2004;79(5):907s-12s.
17. Abargouei AS, Janghorbani M, Salehi-Marzijarani M, Esmaillzadeh A. Effect of dairy consumption on weight and body composition in adults: a systematic review and meta-analysis of randomized controlled clinical trials. International journal of obesity (2005). 2012;36(12):1485-93.
18. Chen M, Pan A, Malik VS, Hu FB. Effects of dairy intake on body weight and fat: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2012;96(4):735-47.
19. Tong X, Dong JY, Wu ZW, Li W, Qin LQ. Dairy consumption and risk of type 2 diabetes mellitus: a meta-analysis of cohort studies. Eur J Clin Nutr. 2011;65(9):1027-31.
20. Gao D, Ning N, Wang C, Wang Y, Li Q, Meng Z, et al. Dairy products consumption and risk of type 2 diabetes: systematic review and dose-response meta-analysis. PLoS One. 2013;8(9):e73965.
21. Rideout TC, Marinangeli CP, Martin H, Browne RW, Rempel CB. Consumption of low-fat dairy foods for 6 months improves insulin resistance without adversely affecting lipids or bodyweight in healthy adults: a randomized free-living cross-over study. Nutr J. 2013;12:56.