Dairy is quite possibly the most controversial food group there is. For centuries, milk and cheese has been a staple of the American diet, and I don’t know many people who don’t profess a dear love for cheese. Dieticians and nutritionists tout dairy foods as having many great nutritional benefits, but some experts also blame them as being part of the problem with the high incidence of obesity, food allergies and degenerative disease. Here in Part One, we’ll take a look at the good things associated with dairy and in Part Two, we’ll talk about the bad. Part Three will try to sort through the controversies and see if we can’t sort out whether or not dairy is good or bad.
The Good
Milk, as stated by The National Dairy Council, is a great source of many vital nutrients. It is a fantastic source of protein, complete with all the essential amino acids. Milk contains both fast-acting whey protein, which also has benefits such as increased immune functioning and increased muscle protein synthesis, and slow release casein protein. At roughly nine grams of protein per one cup serving, milk is a very respectable source of protein. Milk also contains good minerals and vitamins, including ample amounts of calcium, potassium, phosphorus, niacin, riboflavin, and vitamins A, D, and B12. Milk is commonly fortified with additional vitamins to give it an extra punch of benefits (although it could be argued that these additional vitamins aren’t absorbed and used as efficiently as the natural contents). Yogurt has a similar nutritional profile to milk, and some varieties have the additional benefits of live active cultures of probiotic bacteria such as acidophilus and bifidus, that help with the proliferation of good gut bacteria. Cheese is also similar--depending on the type--and all dairy products of course vary in calories, carbohydrate and fat content (depending on whether they are whole milk, low fat or non-fat).
The National Dairy Council declares that dairy products help with numerous health problems, including increased bone density, energy levels, muscle mass, weight loss, and fat oxidation. At the same time, these products help to prevent diabetes, obesity, metabolic syndrome, and any number of other negative health defects. The problem is that the research that they point to in order to support their claims is not only often times bad research, but also very inconclusive, as we will show in the third part of the series. Despite that, there has been a great deal of good research done to show that there are indeed many benefits of integrating dairy into your diet on a regular basis.
Studies have shown that milk is associated with much lower body fat rates than soda in a direct comparison between the two beverages. This would make sense, considering the presence of fat and protein in milk as compared to soda, which is essentially pure sugar and chemicals. Milk is more satisfying because of the presence of the protein and fat (which stimulate more release of the satiety hormone PYY), and it is easier to drink 2-3 servings of soda, with all those “empty calories,” than it is to drink 2-3 servings of milk. It is essentially the equivalent of comparing white bread to whole grain bread. Milk is a much better alternative to things like juice and soda because of the macronutrient content, but the caveat is that you should use the right type of milk (a discussion for later). Research by Dr. John Hartman has also shown that consuming milk after a workout helps to induce muscle gains. That is not surprising when you consider the protein content and quality found in milk. This has lent some credence to the claims of some experts that milk is a great option for a post-workout drink. There has been some promising research showing that the calcium you get from dairy sources is more effective at stimulating weight loss, fat oxidation and increases in bone density than non-dairy supplemented calcium sources. It has also been shown that dairy based calcium can help to decrease fat storage and increase weight and fat loss by inhibiting the active form of vitamin D, 1α,25 Dihydroxyvitamin D3, or calcitriol, which allows the influx of calcium into fat cells to stimulate energy metabolism and growth in those cells. The branched chain amino acids, and ACE-inhibiting whey fractions in milk proteins have also been shown to promote anti-obesity bioactivity.
As evident from the great natural ingredients in dairy foods and research showing very beneficial effects, dairy can be a very good source of nutrition as long as you are getting the right kinds. The right kinds, on the other hand, can be a bit tricky, as we will discuss in the next part of the series. Protein, fat, calcium and a host of other vitamins and minerals make dairy a good thing to eat as long as you can tolerate it.
Next time in Part Two, we will take a look at “The Bad” side of dairy.
Resources:
"Unique Nutrient Combination." NDC Home . The National Dairy Council. Web. 31 Aug. 2011. <http://www.nationaldairycouncil.org/HealthandWellness/Pages/DairysUniqueNutrientCombination.aspx>.
National Institue of Health. "Lactose Intolerance: Information for Health Care Providers."Www.nichd.nih.gov. US Department of Health and Human Services, Jan. 2006. Web. <http://www.nichd.nih.gov/publications/pubs/upload/NICHD_MM_Lactose_FS.pdf>.
Novotny R, Daida YG, Acharya S, Grove JS, Vogt TM. Dairy intake is associated with lower body fat and soda intake with greater weight in adolescent girls. Journal of Nutrition. 2004; 134(8):1905-1909.
Hartman JW, Tang JE, Wilkinson SB, Tarnopolsky MA, Lawrence RL, Fullerton AV and Phillips SM. Consumption of fat-free fluid milk following resistance exercise promotes greater lean mass accretion than soy or carbohydrate consumption in young novice male weightlifters. American Journal of Clinical Nutrition August 2007:86:373– 81.
Lin YC, Lyle RM, McCabe LD, McCabe GP, Weaver CM, Teegarden D. Dairy calcium is related to changes in body composition during a two-year exercise intervention in young women. Journal of the American College of Nutrition. 2000; 19(6):754-760.
Zemel MB, Donnelly JE, Smith BK, Sullivan DK, Richards J, Morgan-Hanusa D, Mayo MS, Sun X, Cook-Wiens G, Bailey BW, Van Walleghen EL, Washburn RA. Effects of dairy intake on weight maintenance. Nutr Metab (Lond). 2008; 5:28.
Zemel MB. The role of dairy foods in weight management. Journal of the American College of Nutrition. 2005 Dec;24(6 Suppl):537S-46S.
Zemel MB, Herweyer A. Role of branched chain amino acids and ACE inhibition in the anti-obesity effect of milk. FASEB Journal. 2007;21:538.11.Abstract.
Shi H, et al. Effects of dietary calcium on adipocyte lipid metabolism and body weight regulation in energy-restricted aP2-agouti transgenic mice. FASEB J. 2001; 15:291-293.
Shi H, et al. 1,25 Dihydroxyvitamin D3 modulates human adipocyte metabolism via nongenomic action. FASEB J. 2001; 15:2751-3.E19.
Nuwanee Kirihennedige – Is a nutritionist and dietician that works with athletes and health minded individuals on sports performance and weight loss. Nuwanee currently is the nutritionist for the California Strength Academy in San Ramon California. Nuwanee can be reached at nuwanee@californiastrength.com.