Got milk? Chances are good that even if you consume milk and other milk products, you’re not meeting the recommended amount, especially if you’re female. According to the 2010 Dietary Guidelines for Americans (DGA), most Americans fall below the recommended servings of fat-free or low-fat milk and milk products. Generally, females consume less than males, and intake declines with age. Adults should aim for three servings of dairy products per day. A standard dairy serving is one cup of milk or yogurt, two cups cottage cheese, or 1½ ounces of hard cheese.
Why should you put milk-based foods on your grocery list? Research suggests that dairy foods and the nutrients they provide can shield you against weak bones, high blood pressure and more. The DGA identify four nutrients of concern. Both children and adults consume too little calcium, vitamin D, potassium and dietary fiber. Dairy products provide all but the fiber.
Bone health. Milk and other dairy products provide calcium, protein, vitamin D, phosphorus, magnesium, and potassium that work synergistically to help build and protect bones, says Melissa Joy Dobbins, M.S., R.D., L.D.N., C.D.E., spokesperson for the Academy of Nutrition and Dietetics. As many as half of all American women and 25 percent of men older than 50 will break a bone because of osteoporosis, a disease characterized by low bone mass, deterioration of bone tissue and increased risk of fractures. Many factors contribute to the development of this bone-thinning disease, including the failure to develop optimal peak bone mass earlier in life. According to a review article in a 2011 issue of the Journal of Dairy Science, researchers found that women who consumed little milk as children and adolescents have lower bone mass. Additionally, low milk intake during childhood is associated with 11 percent increase in osteoporotic fractures in women later in life. When researchers in Finland compared the bone-building effects of cheese to calcium supplements in a study among pre-teen girls, they found that dairy consumption resulted in greater cortical bone mass. (Children age two to three years should consume two servings of dairy, older children through age eight should consume 2 ½ servings, and those nine years and above should aim for three.)
Blood pressure. Population studies suggest that consuming dairy foods lowers the risk of developing high blood pressure. In addition, the Dietary Approaches to Stop Hypertension (DASH) clinical study, funded by the National Heart, Lung, and Blood Institute, showed that a diet high in fruits and vegetables and containing about three servings of dairy foods daily produced greater reductions of both systolic and diastolic blood pressure than either a high fruit and vegetable diet without dairy or a control diet similar to a typical American diet. According to a February 2011 review published in the Journal of Human Hypertension, calcium supplements will also lower blood pressure, though the effect is not as great as the effect of dairy foods. “A combination of nutrients in foods is often more beneficial than a single nutrient in the form of a supplement,” says registered dietitian Robin Ralston, M.S., R.D., one of the authors of the review conducted at Monash University in Australia. “It’s likely the combination of several components of dairy foods that is responsible for the reduced risk of developing elevated blood pressure,” she adds.
Weight loss. Can drinking milk help you lose weight? Some studies say yes and some say no. These conflicting results may occur because of varying study designs, suggests Marta Van Loan, Ph.D., F.A.S.C.M. of the U.S. Department of Agriculture’s Agricultural Research Service. Van Loan and others published the results of their recent study in a 2011 issue of the Journal of Obesity. They fed 71 overweight or obese adults a reduced-calorie diet that was either low or adequate in dairy foods. All of the food was provided to the participants, and they were instructed to consume everything. “We saw no difference in the amount of weight loss between those getting three to four servings per day of dairy compared to those receiving less than one serving per day,” says Van Loan. However, “it appears that participants felt less hungry on the diet with three to four servings per day,” she adds. These results suggest that if dairy foods help dieters lose weight, it is likely because the foods help to squelch hunger, thus reducing calorie intake.
Cancer. “Dairy products seem to help reduce the risk of colorectal cancer,” says Karen Collins, M.S., R.D., C.D.N., nutrition advisor to the American Institute for Cancer Research (AICR). In a meta-analysis for the AICR/World Cancer Research Fund Continuous Update Project involving nearly 1.2 million people, the greatest consumption of total dairy foods compared with the lowest was linked with a 19 percent reduced risk of colorectal cancer. Calcium supplements may also reduce the risk. “Calcium can tie up bile acids formed in the gut, making them unavailable to promote colon cell growth and reproduction. However, it’s possible that other components in milk such as certain components of dairy fat, vitamin D, and others may be protective,” she adds.
Unfortunately, “high consumption of dairy products may increase the risk of prostate cancer,” Collins warns. Men shouldn’t be afraid to consume moderate amounts, however. Two or perhaps three standard servings appear safe and probably lower their risk of colon cancer, she says. “Men who consume dairy products should be cautious about foods that are highly fortified with calcium” and avoid a total calcium intake beyond 1,200 mg/day.
Muscle mass. Along with strength training, eating high quality protein may help build muscle and protect against age-related muscle loss. Dairy protein “contains more branched chain amino acids (BCAA) than many other types of protein,” says Marie Spano, M.S., R.D., C.S.C.S., C.S.S.D., nutritionist for the Atlanta Braves Minor Leagues. BCAA are necessary to build muscle and prevent muscle tissue breakdown. But be sure to time it right; it’s best to consume dairy right after a strength-training workout, she explains, because it stimulates muscle protein synthesis. To get enough dairy protein, Spano often recommends adding whey protein powder to a post-workout smoothie. Muscle tissue recovery and growth is a 24-hour process, however. You should incorporate dairy or protein-rich foods into each meal to ensure adequate protein throughout your day.
When you can’t do dairy. Many people avoid dairy foods because they are lactose intolerant, allergic to milk or prefer not to consume animal products. If lactose intolerance gets in the way of enjoying dairy, “there is good news,” says Dobbins. She explains that those with lactose intolerance can often tolerate yogurt with live active cultures and hard cheeses like cheddar and Parmesan and lactose-free milk. You may even be able to tolerate small amounts of milk, such as one-fourth to one-half cup with a meal. Additionally, you can take lactase enzymes when consuming dairy products to replace the enzymes your body lacks. If you consume no dairy products, you can meet your nutritional needs with fortified soy beverages, according to the DGA. Other milk substitutes fail to stack up nutritionally, warns Dobbins. For example, rice and almond milk each contain only one gram of protein per serving compared to milk’s eight grams.
—Jill Weisenberger, M.S., R.D., C.D.E.