New Dietary Guidelines Emphasize Dairy for Better Health

  • The U.S. government just released the 2015-2020 Dietary Guidelines for Americans, including recommended eating patterns to improve health and reduce the risk of diet-related chronic diseases.
  • Emphasizing that there are many paths to healthy eating, this year’s edition focuses on three different diet patterns: Healthy U.S.-Style Eating Pattern, Healthy Mediterranean-Style Eating Pattern, and Healthy Vegetarian Eating Pattern.
  • Dairy is a key component of each eating pattern, both because it is a nutrient-dense food and because it has a unique combination of nutrients not available in other foods.
  • For adults, consuming the 3-cup per day recommended intake of dairy may be the only way to meet daily requirements for essential nutrients such as calcium, vitamin D, zinc, and potassium.

 

Americans just received their dietary report card, and are doing below average in almost every category [1]. With one in two American adults suffering from a preventable chronic disease [1], we must find ways to improve our marks in nutrition. Every five years, the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) provide help in a nutritional study guide, the Dietary Guidelines for Americans (DGA). The recently announced 2015-2020 DGA tackles many of the same dietary issues highlighted in previous editions (e.g., too much saturated fat, too few vegetables, not enough calcium), but offers a new approach to reaching the recommended healthy diet. Rather than a complete dietary overhaul, Americans are instead encouraged to think about making small shifts in their current diet choices; high-calorie, low-nutritional-value foods and drinks should be substituted with those that are nutrient-dense. Leading DGA’s list of nutrient-dense choices are low- and fat-free dairy foods, including milk, yogurt, and cheese. And because dairy foods offer a set of nutrients (including calcium, protein, potassium, phosphorus, and zinc) not all together found in any other recommended nutrient-dense food, meeting the daily-recommended intake for dairy may be the only way to earn passing grades in all nutritional categories.

From the scientific literature to the dinner table

The goal of the DGA is to “help Americans make healthy choices for themselves and their families” [1]. To determine what “healthy” is for Americans from age 1 to 100, the HHS and USDA enlist top researchers in the fields of nutrition, health, and medicine to scour the scientific literature and make evidence-based recommendations. For example, the recommended three cups per day of dairy for adults is not randomly selected, but grounded in support from numerous studies, including dietary intervention studies with dairy foods (e.g., potential benefits from adding one serving of dairy to bone health in children and adults) as well as those that evaluate at what level more servings would add no additional benefit.

Because science never sleeps, a new edition of the DGA is produced every five years, with the most recent edition (2015-2020) released in December 2015. But not to worry if you have not yet read through the 146-page document to figure out what you should (and should not) be eating. The intended audience is not the American public but nutritional policymakers (e.g., USDA’s National School Breakfast and Lunch Programs) and health care professionals (e.g., pediatricians, nutritionists, primary care physicians).

But in between the many facts and figures is one overarching theme that Americans can easily adopt into their own lives: the need to think about healthy eating in terms of a dietary pattern rather than the inclusion of particular nutrients or foods. After all, when was the last time you heard someone say “I’m really craving some potassium right now?” Although humans have specific nutrient requirements, we consume nutrients in food, and foods as part of a meal, usually comprised of many different food groups. By emphasizing patterns over nutrients, the DGA hopes to make healthy eating something that people of all cultural backgrounds can attain without having to abandon to their current diet [1].

Time to make the shift

DGA-infographic-2.2The 2015-2020 DGA proposes that there are many ways to reach a healthy diet, not simply a one-diet-fits-all mindset that many Americans may find difficult to achieve. But even with dietary flexibility, the DGA emphasizes that all healthy diets need to include fruits, vegetables, protein, dairy, grains, and oils while limiting sodium, added sugars, and saturated and trans fats (Fig. 1). (For more on trans fats click here) [1]. The number of servings of each of these food types varies depending on which healthy diet pattern you choose to follow. This edition offers three choices: Healthy U.S.-Style Eating Pattern, Healthy Mediterranean-Style Eating Pattern, and Healthy Vegetarian Eating Pattern. The latter two are modifications of the Healthy U.S.-Style Eating Pattern; the Mediterranean-style eating pattern contains more fruits and seafood and less dairy, while the Vegetarian-style lacks meats, poultry, and seafood but includes more beans and peas, nuts and seeds, whole grains, and soy products [1].

The DGA argues that these eating patterns are “attainable and relevant in the U.S. population” because they are based off data on the types and proportions of foods that Americans are currently eating [1]. Thus, small modifications or shifts in diet (as opposed to changing the diet as a whole) allow individuals to move closer to one of these patterns. The key is to replace foods (and drinks) with little to no nutrition with those considered nutrient-dense. Nutrient-dense foods provide vitamins, minerals, and other substances such as protein or healthy polyunsaturated fatty acids, but little or no solid fats or added sugars and sodium. Examples include: lean meats, vegetables, fruits, nuts and seeds, and low- and fat-free dairy products.

Dairy foods and healthy eating patterns

Lest you think the DGA aren’t intended for you, here is a startling fact: 75% of the U.S. population currently has an eating pattern that is low in vegetables, fruits, dairy, and oils and exceeds the recommended intake of saturated fats, sugars, and sodium [1]. And if that statistic alone isn’t enough to make you want to give up your fast food lunch, consider the links between diet and health. Currently, 50% of all American adults have one or more diet-related chronic disease, such as type 2 diabetes, high blood pressure, or poor bone health [1]. But there is a silver lining to all of this doom and gloom—these diseases are preventable and can be improved with changes in diet and lifestyle.

For example, the scientific literature offers strong support for prevention and improvement in insulin sensitivity, cardiovascular health, and bone mineral density through dietary changes. Indeed, one food group – dairy – has been shown to have positive effects on each of these health issues. One reason dairy is related to so many health improvements is because it is unique among the nutrient-dense foods in the combination of nutrients it provides: calcium, phosphorus, zinc, potassium, riboflavin, magnesium, selenium, choline, vitamin B12, vitamin A, vitamin D (if fortified), and high-quality protein [1]. In fact, it is such a good source of calcium, potassium, and vitamin D that diet patterns that do not meet the recommended daily intake of dairy are lacking in these essential nutrients [1]. Both the Healthy U.S.-Style Eating Pattern and the Healthy Vegetarian Eating Pattern recommend three servings (cups) of low or fat-free dairy per day, but the Mediterranean diet only recommends two. The guidelines acknowledge that those who follow the Mediterranean diet will have lower daily intakes of calcium and vitamin D than currently recommended, leaving them vulnerable to deficiencies should they not get these nutrients elsewhere (e.g. calcium from green leafy vegetables, vitamin D from sun exposure).

Improving our nutritional GPA

Right now, on the dietary report card, dairy consumption is one of America’s worst nutritional subjects. The DGA estimates that 80% of Americans (age 9 and up) do not meet the recommended daily intake of three servings (serving = 1 cup) (In fact, the only other “subject” for which we have a lower grade is vegetable intake). So when the DGA talks about making shifts, nearly all Americans will benefit from shifts that incorporate more low- or fat-free dairy products. Small substitutions, such as a glass of low-fat milk instead of soda, have the potential of making big impacts on current health and the prevention of chronic disease.

 

1. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at: http://health.gov/dietaryguidelines/2015/guidelines/

 

Contributed by
Dr. Lauren Milligan
Research Associate
Smithsonian Institute