Compendium of the most significant studies with reference to properties, intake, effects.

Marangoni F, Pellegrino L, Verduci E, Ghiselli A, Bernabei R, Calvani R, Cetin I, Giampietro M, Perticone F, Piretta L, Giacco R, La Vecchia C, Brandi ML, Ballardini D, Banderali G, Bellentani S, Canzone G, Cricelli C, Faggiano P, Ferrara N, Flachi E, Gonnelli S, Macca C, Magni P, Marelli G, Marrocco W, Miniello VL, Origo C, Pietrantonio F, Silvestri P, Stella R, Strazzullo P, Troiano E, Poli A. Cow's Milk Consumption and Health: A Health Professional's Guide. J Am Coll Nutr. 2019 Mar-Apr;38(3):197-208. doi: 10.1080/07315724.2018.1491016.

Abstract. The most recent scientific evidence supports the consumption of cow's milk and dairy products as part of a balanced diet. However, these days, the public and practicing physicans are exposed to a stream of inconsistent (and often misleading) information regarding the relationship between cow's milk intake and health in the lay press and in the media. The purpose of this article, in this context, is to facilitate doctor-patient communication on this topic, providing physicians with a series of structured answers to frequently asked patient questions. The answers range from milk and milk-derived products' nutritional function across the life span, to their relationship with diseases such as osteoporosis and cancer, to lactose intolerance and milk allergy, and have been prepared by a panel of experts from the Italian medical and nutritional scientific community. When consumed according to appropriate national guidelines, milk and its derivatives contribute essential micro- and macronutrients to the diet, especially in infancy and childhood where bone mass growth is in a critical phase. Furthermore, preliminary evidence suggests potentially protective effects of milk against overweight, obesity, diabetes, and cardiovascular disease, while no clear data suggest a significant association between milk intake and cancer. Overall, current scientific literature suggests that an appropriate consumption of milk and its derivatives, according to available nutritional guidelines, may be beneficial across all age groups, with the exception of specific medical conditions such as lactose intolerance or milk protein allergy. Key teaching points: Milk and its derivatives contribute essential micro and macronutrients to the diet, when consumed according to appropriate national guidelines, especially in infancy and childhood where bone mass growth is in a critical phase. Preliminary evidence suggests potentially protective effects of milk against overweight, obesity, diabetes and cardiovascular disease No clear data are available about the association between milk intake and cancer. Current scientific literature suggests that an appropriate consumption of milk and its derivatives may be beneficial at all ages, with the exception of specific medical conditions such as lactose intolerance or milk protein allergy.

Alcantara JMA, Sanchez-Delgado G, Martinez-Tellez B, Labayen I, Ruiz JR. Impact of cow's milk intake on exercise performance and recovery of muscle function: a systematic review. J Int Soc Sports Nutr. 2019 May 6;16(1):22. doi: 10.1186/s12970-019-0288-5.

Abstract. Dairy products are thought to improve recovery after both resistance and endurance exercises due to their nutritional proprieties. We systematically reviewed the effects of dairy product intake on exercise performance and recovery of muscle function in humans. A literature search was conducted in the MEDLINE (via PubMed) and Web of Science databases from their inception to 15th April 2018. The initial search retrieved 7708 articles, and a total of 11 studies were finally included after applying inclusion and exclusion criteria. All the selected studies were conducted with cow's milk. Whereas some studies found significant positive effect of cow's milk on exercise performance and recovery of muscle function, others did not find any effect. These controversies could be due to the heterogeneity of cow's milk ingestion (e.g., amount of cow's milk, timing of consuming the cow's milk), to the type of intervention, and to the large heterogeneity of outcomes measured. Limited studies exist examining the effects of cow's milk consumption and its influence on exercise performance and recovery of muscle function, therefore further studies are needed to draw more definitive conclusions.

Foroutan A, Guo AC, Vazquez-Fresno R, Lipfert M, Zhang L, Zheng J, Badran H, Budinski Z, Mandal R, Ametaj BN, Wishart DS. Chemical Composition of Commercial Cow's Milk. J Agric Food Chem. 2019 May 1;67(17):4897-4914. doi: 10.1021/acs.jafc.9b00204. 

Abstract. Bovine milk is a nutritionally rich, chemically complex biofluid consisting of hundreds of different components. While the chemical composition of cow's milk has been studied for decades, much of this information is fragmentary and very dated. In an effort to consolidate and update this information, we have applied modern, quantitative metabolomics techniques along with computer-aided literature mining to obtain the most comprehensive and up-to-date characterization of the chemical constituents in commercial cow's milk. Using nuclear magnetic resonance (NMR) spectroscopy, liquid chromatography-mass spectrometry (LC-MS), and inductively coupled plasma-mass spectrometry (ICP-MS), we were able to identify and quantify 296 bovine milk metabolites or metabolite species (corresponding to 1447 unique structures) from a variety of commercial milk samples. Through our literature analysis, we also found another 676 metabolites or metabolite species (corresponding to 908 unique structures). Detailed information regarding all 2355 of the identified chemicals in bovine milk have been made freely available through a Web-accessible database called the Milk Composition Database or MCDB ( http://www.mcdb.ca/ ).

Corazzin M, Romanzin A, Sepulcri A, Pinosa M, Piasentier E, Bovolenta S. Fatty Acid Profiles of Cow's Milk and Cheese as Affected by Mountain Pasture Type and Concentrate Supplementation. Animals (Basel). 2019 Feb 22;9(2):68. doi: 10.3390/ani9020068.

Abstract. The aim of this trial was to assess the effect of pasture type and concentrate supplementation on the fatty acids (FA) composition of milk and cheese obtained during summer grazing on mountain pasture. Seventy-two Italian Simmental dairy cows were assigned to two groups that differed by the amount of concentrate supplementation: 3.0 kg/head/d (HIGH) vs. 1.5 kg/head/d (LOW). The dairy cows grazed on a Poion alpinae alliance pasture (PAST1), and subsequently they grazed on a Seslerion caeruleae alliance pasture (PAST2) for 10 d each. In the last three days of each experimental period, milk samples were collected immediately before each cheese-making event. Cheese samples were collected from each cheese loaf after 60 d of ripening. LOW showed higher isoFA, FA intermediates of the ruminal biohydrogenation, C18:3 c9,c12,c15, and total polyunsaturated fatty acid (PUFA) levels than HIGH. The pasture type had a more limited effect on FA composition of milk than concentrate level and was mainly related to monounsaturated fatty acids (MUFA), which were higher in PAST1 than PAST2 (p < 0.05). In cheeses, these differences were reduced. The phytanic acid and phytanic isomer ratio (SRR/RRR) in milk were not affected either by supplement level (p > 0.05) or by type of pasture (p > 0.05). Increasing the concentrate offered to dairy cows from 1.5 to 3.0 kg/d did not markedly influence the level of PUFA in cheeses produced during summer grazing on high mountain pasture.

Thorning TK, Raben A, Tholstrup T, Soedamah-Muthu SS, Givens I, Astrup A. Milk and dairy products: good or bad for human health? An assessment of the totality of scientific evidence. Food Nutr Res. 2016 Nov 22;60:32527. doi: 10.3402/fnr.v60.32527.

Abstract. Background: There is scepticism about health effects of dairy products in the public, which is reflected in an increasing intake of plant-based drinks, for example, from soy, rice, almond, or oat. Objective: This review aimed to assess the scientific evidence mainly from meta-analyses of observational studies and randomised controlled trials, on dairy intake and risk of obesity, type 2 diabetes, cardiovascular disease, osteoporosis, cancer, and all-cause mortality. Results: The most recent evidence suggested that intake of milk and dairy products was associated with reduced risk of childhood obesity. In adults, intake of dairy products was shown to improve body composition and facilitate weight loss during energy restriction. In addition, intake of milk and dairy products was associated with a neutral or reduced risk of type 2 diabetes and a reduced risk of cardiovascular disease, particularly stroke. Furthermore, the evidence suggested a beneficial effect of milk and dairy intake on bone mineral density but no association with risk of bone fracture. Among cancers, milk and dairy intake was inversely associated with colorectal cancer, bladder cancer, gastric cancer, and breast cancer, and not associated with risk of pancreatic cancer, ovarian cancer, or lung cancer, while the evidence for prostate cancer risk was inconsistent. Finally, consumption of milk and dairy products was not associated with all-cause mortality. Calcium-fortified plant-based drinks have been included as an alternative to dairy products in the nutrition recommendations in several countries. However, nutritionally, cow's milk and plant-based drinks are completely different foods, and an evidence-based conclusion on the health value of the plant-based drinks requires more studies in humans. Conclusion: The totality of available scientific evidence supports that intake of milk and dairy products contribute to meet nutrient recommendations, and may protect against the most prevalent chronic diseases, whereas very few adverse effects have been reported.

Konstantynowicz J, Nguyen TV, Kaczmarski M, Jamiolkowski J, Piotrowska-Jastrzebska J, Seeman E. Fractures during growth: potential role of a milk-free diet. Osteoporos Int. 2007 Dec;18(12):1601-7. doi: 10.1007/s00198-007-0397-x. 

Abstract. Dietary calcium deficiency may increase fracture risk. In girls, 29.4% of fracture cases and 11.8% of controls without fracture had a history of milk-free diet. The odds ratio (OR) for fracture with a milk-free diet in girls was 4.6, p < 0.01. In boys, 23% of cases and 19% of controls had a history of a milk-free diet; OR = 1.3, NS). A milk-free diet due to cow's milk allergy is associated with increased fracture risk in girls. Introduction: An intake of calcium below the reference daily intake (RDI) of 800-1200 mg/day during growth is thought to increase fracture risk even though convincing evidence for this view is scarce. The paucity of evidence may be partly due to many trial participants being calcium replete. Children and adolescents with cow's milk allergy (CMA) avoid milk and have a calcium intake below the RDI. The aim of this study was to examine the association between consumption of a milk-free diet and fracture risk....Conclusions: Cow's milk allergy is associated with increased fracture risk in girls. Whether this association is due to the illness, calcium deficit or a deficit in other milk nutrients is uncertain. These data suggest that the contribution of milk-free diet to fracture liability among children and adolescents is modest.