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Educate your patients on the importance of 3-A-Day of Dairy: Here's
a great
tool (PDF: 618k) to show families how to get their 3-A-Day of Dairy
every day for stronger bones.
Developed in conjunction with The American Academy of Family
Physicians, The American Academy of Pediatrics, The American Dietetic
Association, and The National Medical Association.
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Dairy Council Digest Archives
The Benefits of Dairy Foods in Health Promotion
Dairy Foods' Role in Reducing the Risk for Various Medical Disorders
Osteoporosis . A large body of scientific evidence demonstrates that adequate intake of calcium and calcium-rich foods such as milk, cheese, or yogurt positively affects bone health by increasing bone acquisition during growth, slowing age-related bone loss, and reducing osteoporotic fragility fractures (4,8-11). Osteoporosis is a skeletal disease in which bones weaken and risk of fractures increases (9). Bone mass in later adult years is primarily influenced by peak bone mass, about 90% of which is reached by 20 years of age (10).
According to the recent National Institute of Health (NIH) Consensus Statement on Osteoporosis (9), "calcium is the specific nutrient most important for attaining peak bone mass and for preventing and treating osteoporosis." This statement is supported by findings from an analysis of139 studies published between1975 and1999 describing the relationship of calcium intake and bone health in children and adults (11). In this analysis, all but two of 52 randomized intervention studies demonstrated that calcium intake increased bone gain during growth and reduced bone loss and/or fractures in later adult years (11). Three-quarters of the 86 observational studies supported calcium's beneficial effect on bone health. All of the studies that used dairy foods as a source of calcium reported a positive link between dairy foods and bone health (11).
In addition to calcium, milk and other dairy foods provide several other nutrients such as phosphorus, vitamin D (if fortified), protein, and magnesium, which are beneficial to bone health (8,10). Dairy foods are considered to be among the best sources of calcium because of their high content of this mineral, overall nutritional value, and relatively low cost (1,12). Recognizing the importance of adequate calcium intake and good nutrition during childhood and adolescence to maximize peak bone mass and reduce the risk of osteoporosis in later adult years, the American Academy of Pediatrics urges pediatricians to recommend milk, cheese, yogurt, and other calcium-rich foods for children's daily diets (13). This recommendation is supported by several recent studies demonstrating that consuming dairy foods benefits children's bone health (14-16).
Researchers in New Zealand found that children ages 3 to 13 years with a history of avoiding drinking cow's milk for prolonged periods had lower dietary calcium intakes, lower bone mineral density of the total skeleton and at specific skeletal sites, and increased risk of prepubertal bone fractures compared with milk-drinking children (14,15). In a recent clinical trial involving 28 healthy boys between 13 and 17 years who participated in a strength training program, those who drank three servings of milk a day in addition to their usual diet had significantly greater increases in bone mineral density compared to boys who consumed unfortified juice (16).
When data from more than 3,000 women who participated in the third National Health and Nutrition Examination Survey (NHANES) were analyzed, researchers found that women with low milk intake during childhood and adolescence had less bone mass in adulthood and greater risk of fractures (17). The researchers attributed milk's combination of nutrients (e.g., calcium, protein, phosphorus, vitamin D, zinc, and magnesium) to this food's positive effects on bone growth and mineralization (17). The author of an accompanying editorial states that the combination of nutrients in milk "may have a greater effect on enduring skeletal integrity than does calcium given in a short-term supplementation program" (18).
Adult skeletal health is also improved by increasing dairy food or calcium intake (19- 25). In postmenopausal Chinese women who increased their milk consumption, bone loss was reduced and bone mineral density was increased (19,20). Drinking at least three servings of fat free or lowfat milk each day significantly reduced bone resorption in older adults, according to a multicenter, randomized controlled trial (21). Likewise, bone resorption was reduced in postmenopausal women with habitual low calcium intakes who increased their intake of calcium and other nutrients by adding three servings of yogurt a day to their diet (22).
Two major studies – the Dietary Approaches to Stop Hypertension (DASH) and the Coronary Artery Risk Development in Young Adults (CARDIA) – provide strong evidence of the health benefits of a diet that includes adequate amounts of dairy products.
Other studies have shown that intake of multiple nutrients (e.g., calcium, vitamin D, phosphorus), as exist in dairy foods, reduce the risk of fractures (8,11,23) and falls (24). The DASH (Dietary Approaches to Stop Hypertension) diet – a lowfat, calcium-rich diet that emphasizes lowfat dairy foods (2-3 servings/day), fruits (4-5 servings/day), vegetables (4-5 servings/day), grains, and lean meat – has been shown to reduce bone turnover, which, if sustained, may improve bone mineral status and reduce the risk of osteoporosis (25).
Based on scientific evidence supporting a beneficial role for dairy foods in bone health and recognition of Americans' low consumption of dairy foods resulting in low calcium intakes, the dairy industry, with support from health professional partners (e.g., American Academy of Family Physicians, American Academy of Pediatrics, American Dietetic Association, National Medical Association) has initiated a nutrition-based marketing and education campaign called "3-A-Day of Dairy for Stronger Bones." The key message is to consume three or more daily servings of milk, cheese, or yogurt to help build and maintain strong bones and achieve overall health. For more information, visit www.3aday.org.
Hypertension . Substantial scientific evidence indicates that increasing consumption of dairy foods or calcium lowers the risk of hypertension or reduces blood pressure (4,5,26-29). Although blood pressure responses to nutrient intakes such as calcium vary among individuals, the beneficial effect tends to be more consistent when foods rather than calcium supplements are used as the mineral source (5,28,30,31).
The blood pressure-lowering effect of dairy products is best exemplified by the DASH clinical trial (5). In this government sponsored, controlled feeding intervention, blood pressure was substantially and quickly reduced in persons with high-normal blood pressure who consumed the DASH diet (5). In those who consumed the diet rich in fruits and vegetables but without dairy products, blood pressure reductions were approximately half the magnitude as found with the DASH diet which included three servings of mostly lowfat dairy products/ day (5). The researchers estimated that if Americans follow the DASH diet, blood pressure improvements would rival those obtained with antihypertensive medications (5).
The DASH findings have been confirmed by results from the DASH-Sodium trial (31). In addition, the DASH diet favorably modifies salt's effect on blood pressure in subjects at risk of "salt sensitivity." Results of the PREMIER trial support the benefits of lifestyle modifications (e.g., weight loss, alcohol restriction, increased physical activity), including the DASH diet, for reducing blood pressure (32). Dairy products are among the top contributors of several nutrients such as calcium, potassium, and magnesium (i.e., nutrients shown to lower blood pressure) provided by the DASH and DASH-Sodium diets (33).
Recently published findings from the CARDIA (Coronary Artery Risk Development in Young Adults) study, a multi-center prospective study involving more than 3,000 young adults followed for10 years, show a consistent reduction in hypertension with high consumption of dairy foods in initially overweight individuals (6). The likelihood of elevated blood pressure was nearly 20% lower for each daily eating occasion of dairy products (6).
The National Heart, Lung, and Blood Institute, in its most recent (7th) Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends lifestyle modifications (34). The report ranks the DASH diet as the most effective nutritional intervention ahead of sodium restriction.
Overweight and Obesity . As discussed in the previous Digest (35) and in recent reviews (36-38), emerging scientific evidence indicates that dairy products and calcium have a beneficial role in controlling body weight/fat in children and adults. Findings indicate that dairy products have greater effects on body weight than predicted from their calcium content alone. A recent randomized controlled clinical trial in obese adults demonstrated that consumption of dairy products significantly accelerated body weight and fat loss (39).
Dairy foods appear to be more effective than calcium alone in reducing the risk for a number of chronic diseases.
Insulin Resistance and Type 2 Diabetes . Dietary patterns characterized by increased dairy consumption may protect overweight individuals from developing obesity and insulin resistance syndrome (IRS), which are key risk factors for type 2 diabetes and heart disease, according to the CARDIA study (6). In this study, overweight participants who consumed the most dairy products (more than 5 servings/ day) had an approximately 70% lower incidence of IRS than those who consumed few dairy products (less than 1.5 servings/day). IRS, known as the metabolic syndrome or syndrome X, is characterized by abnormal blood glucose control, high blood pressure, and abnormal blood lipid levels (low HDL cholesterol and high triglycerides) (6). One study found that the prevalence of metabolic syndrome was 40% lower in men who consumed one or more servings of dairy products/day than those who consumed less (40). Reduced risk of type 2 diabetes has been reported in randomized clinical trials that used lowfat dairy foods as a component of dietary interventions (41,42).
Coronary Heart Disease and Stroke . In addition to its beneficial effect on hypertension (5), the DASH diet, which contains dairy foods, positively affects other risk factors for heart disease. This diet has been shown to significantly reduce blood total and low density lipoprotein (LDL) cholesterol without affecting blood triglyceride levels (43) and to lower blood levels of homocysteine, an amino acid linked to increased risk of heart disease and stroke (44). Based on the reduction in homocysteine levels, researchers project that intake of the DASH diet could lower atherosclerotic cardiovascular disease by 7% to 9% (44), in addition to the 15% reduction in heart disease and 27% reduction in stroke estimated by the DASH-induced decrease in blood pressure (5). Intake of dairy foods may also reduce the risk for obesity and insulin resistance syndrome, which are additional risk factors for heart disease (35-39).
Consuming dairy foods increases intake of nutrients such as calcium, potassium, and magnesium, which may protect against heart disease either directly or through effects on blood lipids, blood pressure, and body weight (45). Increasing calcium intake has been demonstrated to result in a blood lipoprotein-lipid profile that is associated with a reduction in the risk of coronary heart disease (46-48). A recent study of nearly 500 adults participating in phase 2 of the Quebec Family Study found that higher calcium intake, primarily from dairy products, was negatively correlated with plasma LDL cholesterol, total cholesterol, and the ratio of total cholesterol to high density lipoprotein (HDL) cholesterol (48).
Dairy products and dairy product nutrients such as calcium, potassium, and magnesium may help to reduce the risk of stroke, a type of cardiovascular disease (29,49). Consumption of dairy foods, such as milk, may have a greater effect on reducing risk of stroke than nondairy sources of calcium (49).
Cancer . Intake of dairy foods may lower the risk for certain cancers. Epidemiological investigations report inverse associations between calcium, vitamin D, and dairy food intake and colon cancer (50-54). A clinical trial of 40 adults at high risk for colon cancer found that increasing intake of lowfat dairy foods (i.e., three additional servings of lowfat dairy foods for a total of approximately1, 300mg/day) or calcium (900mg supplemental calcium plus 600 mg dietary calcium for a total intake of approximately1, 500mg calcium/day) for four months significantly reduced the growth of abnormal cells thought to precede colon cancer development (55). A previous study by these researchers found that a diet supplemented with lowfat dairy foods providing a total calcium intake of approximately 1,500mg/day significantly decreased proliferation of colonic epithelial cells (56). The combination of calcium and vitamin D may be particularly effective in preventing the recurrence of colon cancer, according to a recent randomized clinical trial (57). This finding supports the suggestion that dietary calcium may be more effective than calcium supplements in reducing the risk for colon cancer (58).
Preliminary epidemiological evidence suggests a protective effect of dairy products against breast cancer (59-62). In a 6-year prospective study of premenopausal Norwegian women, those who consumed more than three 8-ounce servings of milk/day had a 44% lower incidence of breast cancer than nonmilk drinkers (60). Consumption of dairy products, especially lowfat dairy products and skim/lowfat milk, was associated with a significantly reduced risk of breast cancer in premenopausal, but not postmenopausal, women participating in the Nurses' Health Study (59).
More research is needed to determine how intake of dairy foods such as milk may help reduce the risk of developing colon or breast cancer. However, researchers have suggested an anticancer effect for several nutrients in dairy foods such as calcium, vitamin D, and certain milkfat components (e.g., conjugated linoleic acid, sphingolipids, butyric acid) (63,64).
Dental Health . Dairy foods such as milk and especially cheese may play a protective role in dental health, according to findings from experimental animal, in vitro, and limited epidemiological studies (4,65-67). Studies show that milk intake does not promote dental caries and may even have a modest caries-protective effect and that different types of cheese (e.g., Cheddar, Swiss, blue, Monterey Jack, process American) may protect teeth against caries (4,65-67). Moreover, researchers have suggested that nutrients in milk and cheese such as protein, calcium, and phosphorus may contribute to the protective effect of these foods against dental caries (67).
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