Category Archives: Dairy

Review: Dairy for Bones

Abstract

Invited review: Dairy intake and bone health: a viewpoint from the state of the art.

The aim of this review was to focus on the complex relationships between milk and dairy products intake and bone health, with particular emphasis on osteoporosis. The literature was extensively examined to provide an objective overview of the most significant achievements on the subject. Osteoporosis can be defined as a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk. Although the major determinants of peak bone mass and strength are genetic, major factors during childhood and adolescence may affect the ability to achieve peak bone mass. These include nutrition, particularly calcium and protein intake, physical activity, endocrine status, as well as exposure to a wide variety of risk factors. The role of calcium intake in determining bone mineral mass is well recognized to be the most critical nutritional factor to achieve optimal peak bone mass. The greatest amount of dietary calcium is obtained from milk and dairy foods, which also provide the human diet with vitamin D (particularly for products fortified with vitamin D), potassium, and other macro- and micronutrients. Although studies supporting the beneficial effects of milk or calcium on bone health are predominant in the literature, perplexity or discordance on this subject was expressed by some authors. Discordant data, mainly on the risk of fractures, provided limited proof of the unfavorable effect of dairy intake. More often, discordant works indicate no effect of dairy consumption on bone safety. Some considerations can be drawn from this viewpoint. Milk and dairy products are an optimal source of calcium as well as of other limiting nutrients (e.g., potassium and magnesium), with important effects on bone health. Bioactive components occurring in milk and dairy products may play an essential role on bone metabolism, as shown by in vivo and in vitro studies on colostrum acidic proteins and milk basic proteins. Calcium intake positively affects bone mass and is crucial in childhood and youth for correct bone development. In elderly people, calcium intake as well as vitamin D availability should be carefully checked. As a general conclusion, calcium is essential for bone health, although it will not prevent bone loss due to other factors; in this context, milk and dairy foods are bioavailable, relatively inexpensive sources of calcium for the human diet.

Caroli A, Poli A, Ricotta D, Banfi G…
J. Dairy Sci. Nov 2011
PMID: 22032348 | Free Full Text

This article reviews some of the negative studies on dairy for bones. Including this study. The article concludes with:

In any case, some general conclusions can be drawn. First, milk and dairy products are an optimal source of calcium as well as other limiting nutrients (e.g., potassium and magnesium), with important effects on bone health. Bioactive components occurring in milk and dairy products may play an essential role in bone metabolism, as shown by colostrum acidic proteins and MBP. Calcium intake positively affects bone mass and is crucial in childhood and youth for correct bone development. In elderly people, calcium intake as well as vitamin D availability should be carefully checked. The literature reporting favorable effects of milk and dairy products on bone is highly predominant compared with contradictory papers, including discordant and perplexing works. Discordant data, mainly on the risk of fractures, provided limited proof of the unfavorable effects of dairy intake. The majority of the contradictory papers indicate that dairy consumption does not alter bone safety. The best conclusion comes from Lindsay and Nieves (1994):

“Calcium will not prevent the bone loss due to other factors . . . nonetheless, milk is a bioavailable, relatively inexpensive source of calcium for those who can ingest it.”

Milk Increases Risk of Fracture in Women

Abstract

Milk, dietary calcium, and bone fractures in women: a 12-year prospective study.

This study examined whether higher intakes of milk and other calcium-rich foods during adult years can reduce the risk of osteoporotic fractures.
This was a 12-year prospective study among 77761 women, aged 34 through 59 years in 1980, who had never used calcium supplements. Dietary intake was assessed with a food-frequency questionnaire in 1980, 1984, and 1986. Fractures of the proximal femur (n = 133) and distal radius (n = 1046) from low or moderate trauma were self-reported on biennial questionnaires.
We found no evidence that higher intakes of milk or calcium from food sources reduce fracture incidence. Women who drank two or more glasses of milk per day had relative risks of 1.45 for hip fracture (95% confidence interval [CI] = 0.87, 2.43) and 1.05 for forearm fracture (95% CI = 0.88, 1.25) when compared with women consuming one glass or less per week. Likewise, higher intakes of total dietary calcium or calcium from dairy foods were not associated with decreased risk of hip or forearm fracture.
These data do not support the hypothesis that higher consumption of milk or other food sources of calcium by adult women protects against hip or forearm fractures.

Feskanich D, Willett WC, Stampfer MJ, Colditz GA
Am J Public Health Jun 1997
PMID: 9224182 | Free Full Text

Review: Nutrition for Osteoporosis

Abstract

Osteoporosis prevention and nutrition.

Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, recent research has clarified the importance of several additional nutrients and food constituents. Further, results of calcium and vitamin D supplementation trials have been inconsistent, suggesting that reliance on this intervention may be inadequate. In addition to dairy, fruit and vegetable intake has emerged as an important modifiable protective factor for bone health. Several nutrients, including magnesium, potassium, vitamin C, vitamin K, several B vitamins, and carotenoids, have been shown to be more important than previously realized. Rather than having a negative effect on bone, protein intake appears to benefit bone status, particularly in older adults. Regular intake of cola beverages shows negative effects and moderate alcohol intake shows positive effects on bone, particularly in older women. Current research on diet and bone status supports encouragement of balanced diets with plenty of fruit and vegetables, adequate dairy and other protein foods, and limitation of foods with low nutrient density.

Tucker KL
Curr Osteoporos Rep Dec 2009
PMID: 19968914

Video: Dr. Hofflich “Osteoporosis Update 2013” – Stein Institute for Research on Aging

Here is a nice talk by Dr. Heather Hofflich from May 15, 2013. She’s an Associate Professor of Medicine at UCSD. She gives an overview of osteoporosis and discusses the causes and therapies used to treat it. She also takes a look at recent controversies in treatment plans and vitamin usage.

One thing that bothers me about her talk is that she claims Teriparatide is the only thing in the world that builds bone by increasing osteoblast activity. I’ve posted many studies that found increases in osteoblasts from a variety of things. She also didn’t mention any other potentially helpful dietary supplements besides Calcium and Vitamin D. Like most MDs, she is probably unaware of anything that is not FDA approved.

Milk Basic Protein Inhibits Resorption in Ovariectomized Rats

Abstract

Milk basic protein: a novel protective function of milk against osteoporosis.

Milk is recommended as an excellent calcium source for bone health. Moreover, milk is considered to contain other components effective for bone health. In our previous studies, using an unfractionated bone cell culture system, we found that milk whey protein, especially its basic fraction (milk basic protein [MBP]), suppressed bone resorption. In this present study, we investigated whether MBP could prevent bone loss in aged ovariectomized rats. Twenty-one 51-week-old female Sprague-Dawley rats were ovariectomized (ovx), and another seven rats received a sham operation (sham). After a 4-week recovery period, the ovx rats were separated into three groups, and they were then fed a control diet, a 0.01% MBP diet (0. 01% casein of the control diet replaced with MBP), or a 0.1% MBP diet for 17 weeks. The sham rats were fed the control diet. Bone mineral density (BMD) of the femur was measured by dual-energy X-ray absorptiometry in vivo. The BMD in the ovx-control group noticeably decreased during the experimental period in comparison with that in the sham group. However, the BMD in the OVX-0.1% MBP group was significantly higher than that in ovx-control group at weeks 12 and 16 (p < 0.05). After the 17-week feeding period, the breaking energy of the excised femur of all groups was determined by use of a three-point bending rheolometer. The breaking energy in the ovx-control group was significantly lower than that in the sham group (p < 0.05). However, the breaking energy in the ovx-0.1% MBP group was significantly higher than that of the ovx-control group (p < 0.05). Urinary deoxypyridinoline (D-Pyr) level of the ovx-control group was higher than that of the sham group, whereas the level of D-Pyr excretion in the ovx-0.01% MBP and ovx-0.1% MBP groups was significantly lower than that of the ovx-control group (p < 0.05). These results suggest that MBP suppresses the osteoclast-mediated bone resorption and prevents bone loss caused by ovariectomy. Moreover, we performed an in vitro study using isolated osteoclasts from rabbit bone to investigate the possible mechanism. MBP dose-dependently suppressed the number of pits formed by these osteoclasts. This result indicates that MBP suppresses bone resorption by its direct effects on osteoclasts. To our knowledge, this study provides the first evidence that MBP directly suppresses osteoclast-mediated bone resorption, resulting in the prevention of the bone loss that occurs in ovx rats.

Toba Y, Takada Y, Yamamura J, Tanaka M…
Bone Sep 2000
PMID: 10962352

Fermented Milk Reduces Bone Resorption

Abstract

Short-term effect of bedtime consumption of fermented milk supplemented with calcium, inulin-type fructans and caseinphosphopeptides on bone metabolism in healthy, postmenopausal women.

Milk products are good sources of calcium and their consumption may reduce bone resorption and thus contribute to prevent bone loss.
We tested the hypothesis that bedtime consumption of fermented milk supplemented with calcium inhibits the nocturnally enhanced bone resorption more markedly than fermented milk alone, and postulated that this effect was most pronounced when calcium absorption enhancers were added.
In a controlled, parallel, double-blind intervention study over 2 weeks we investigated the short-term effects of two fermented milks supplemented with calcium from milk minerals (f-milk + Ca, n = 28) or calcium from milk minerals, inulin-type fructans and caseinphosphopeptides (f-milk + Ca + ITF + CPP; n = 29) on calcium and bone metabolism in healthy, postmenopausal women, and compared them with the effect of a fermented control milk without supplements (f-milk, n = 28). At bedtime 175 ml/d of either test milk was consumed. Fasting blood samples and 48 h-urine were collected at baseline and at the end of the intervention. Urine was divided into a pooled daytime and nighttime fraction. Multifactorial ANOVA was performed.
Fermented milk independent of a supplement (n = 85) reduced the nocturnal excretion of deoxypyridinoline, a marker of bone resorption, from 11.73 +/- 0.54 before to 9.57 +/- 0.54 micromol/mol creatinine at the end of the intervention (P = 0.005). No effect was seen in the daytime fraction. Differences between the three milks (n = 28 resp. 29) were not significant. Fermented milk reduced bone alkaline phosphatase, a marker of bone formation, from 25.03 +/- 2.08 to 18.96 +/- 2.08 U/l, with no difference between these groups either. Fermented milk increased the nocturnal but not daytime urinary excretion of calcium and phosphorus. The effects on calcium and phosphorus excretion were mainly due to the group supplemented with Ca + ITF + CPP.
Bedtime consumption of fermented milk reduced the nocturnal bone resorption by decelerating its turnover. Supplemented calcium from milk mineral had no additional effect unless the absorption enhancers ITF + CPP were added. A stimulated intestinal calcium absorption may be assumed, since urinary calcium excretion increased at a constant bone resorption.

Adolphi B, Scholz-Ahrens KE, de Vrese M, Açil Y…
Eur J Nutr Feb 2009
PMID: 19030908

Review: Milk + Resistance Training

Abstract

Impact of milk consumption and resistance training on body composition of female athletes.

Resistance exercise (RE) preceding the provision of high-quality dairy protein supports muscle anabolism. Milk contains bioactive components, including two high-quality protein fractions, calcium and vitamin D, each of which has been shown modulate body composition (increasing lean mass and decreasing fat mass) under energy balance and hypoenergetic conditions. These dairy nutrients are also essential for skeletal health. Acutely, no study of RE and milk/whey consumption has been undertaken exclusively in female athletes, let alone women, nevertheless, studies with both men and women show increased lean mass accretion following milk/whey compared to soy/placebo. Currently, no longer-term RE studies with milk supplementation have been done in female athletes. However, trials in young recreationally active women demonstrated augmented increases in lean mass and decreases in fat mass with RE and milk or whey protein consumption. The amount of protein consumed post-exercise is also important; two trials using yogurt (5 g protein/6 oz) failed to demonstrate a positive change in body composition compared to placebo. For bone health, RE plus dairy improved bone mineral density at clinically important sites and reduced bone resorption. With energy restriction, in one study, higher dairy plus higher protein resulted in greater fat loss, lean mass gain and improved bone health in overweight women. In another study, milk and calcium supplementation showed no greater benefit. Neither trial exclusively utilized RE. Overall, RE and milk/dairy consumption positively impact body composition in women by promoting losses in fat, gains or maintenance of lean mass and preservation of bone. Future studies in female athletes and under energy restriction with RE alone are warranted.

Josse AR, Phillips SM
Med Sport Sci 2012
PMID: 23075559