Diabetes self-management education is an integral part of the role of diabetes care practitioners. However, guiding patients with diabetes toward a path of better health is a growing challenge for a variety of reasons. Diabetes ranks as the seventh-leading cause of death, affecting 25.8 million people (8.3%) in the U.S. population. In addition, 35% of adults in the United States ≥ 20 years of age have prediabetes.1 For patients with diabetes or prediabetes, the diagnosis is frequently accompanied by other comorbidities, including hypertension, dyslipidemia, and obesity. This means treatment guidelines must focus not only on blood glucose management, but also on controlling lipids, blood pressure, and body weight.2 Although glycemic control is an important aspect of health and well-being for patients with diabetes, there are more pieces to the puzzle of effective diabetes management.
Adults with diabetes have a risk of death from coronary heart disease that is two to four times higher than that of adults without diabetes. Yet, of people with diabetes ≥ 20 years of age, 67% have blood pressure readings of ≥ 140/90 mmHg or are taking prescription hypertension agents.1 These statistics make it clear that diabetes practitioners have an opportunity to support their patients in achieving improvements in areas commonly referred to as “the ABCs of diabetes management”: A1C, blood pressure, and cholesterol.
Lifestyle modification is a cornerstone of management for diabetes and prediabetes. A multitude of guidelines exist regarding proper nutrition, especially with regard to managing chronic conditions such as diabetes, hypertension, and dyslipidemia. Unfortunately, consumers are also bombarded with mixed messages about nutrition from numerous sources. It can be difficult to decipher fact from fiction and to answer one of the simplest questions often asked by patients with diabetes: “What can I eat?”
The Dietary Guidelines for Americans, most recently published in 2010, are a key source of nutrition guidance in the United States. In preparing the most recent version of these guidelines, the U.S. Department of Agriculture and the U.S. Department of Health and Human Services reviewed several different healthy eating patterns, all of which included an abundance of fruits and vegetables, an emphasis on whole grains, and limited amounts of added sugars and solids fats.
The Dietary Approaches to Stop Hypertension (DASH) eating pattern was suggested as one such embodiment of these dietary recommendations.3 This article reviews the DASH eating pattern and how it can be tailored to help patients with diabetes or prediabetes achieve their goals for managing blood pressure, lipid, weight, and glucose levels.
What Is the DASH Eating Pattern?
The DASH trial, originally published in 1997, reviewed the impact of eating patterns on blood pressure management. Specifically, subjects were fed either a diet rich in fruits and vegetables or a combination diet that was both rich in fruits and vegetables and low-fat dairy foods and low in saturated fat. The study authors concluded that this eating pattern was effective in reducing blood pressure levels within 2 weeks. Because the study subjects were a heterogeneous representation of the U.S. population and the foods included were widely available, they also concluded that these eating patterns could be easily adopted by most people in the United States.4
Information about the DASH eating plan and how to implement it is widely available to anyone who might be interested in learning more. The eating pattern, along with overall recommendations, information on its benefits for blood pressure management, and sample meal plans and recipes can be obtained through the National Heart, Lung, and Blood Institute.5 Table 1 provides an outline of the recommended number of servings from each food group, based on two different levels of caloric intake—1,600 and 2,000 calories per day.
Effectiveness of the DASH Eating Pattern
A wide array of research exists about the DASH eating plan and its benefits for controlling hypertension and other cardiovascular risk factors. According to a scientific statement from the American Heart Association, the DASH eating plan significantly reduced blood pressure in all major subgroups (regardless of sex, race, or hypertensive status). This outcome is produced by multiple aspects of the diet rather than from one food or nutrient alone, and it is achieved in as little as 2 weeks after implementing the intervention.6
There is also a growing body of evidence pointing to the benefits of sodium reduction in addition to the DASH eating plan as a way to prevent cardiovascular disease and stroke.7 This may be particularly important because individuals with hypertension have a higher risk of developing insulin resistance and diabetes, and the combination of diabetes and hypertension greatly increases the risk of heart disease, stroke, kidney disease, and heart failure.8
Although the benefits of the DASH eating plan for hypertension control and cardiovascular disease risk reduction are well documented, there is less research on the eating plan's specific benefits for diabetes management.
In one small, randomized cross-over clinical trial of 33 subjects with type 2 diabetes in Iran,9 subjects received either a control diet or a diet based on the DASH eating plan. Results revealed that, although all subjects had a similar caloric intake, those on the DASH eating plan consumed foods that were lower in caloric density and saw greater reductions in fasting blood glucose levels, A1C, body weight, and waist circumference. The authors concluded that the DASH eating pattern may reduce cardio-metabolic risk in patients with type 2 diabetes, but longer-term studies are needed.
Two other studies have looked at the eating pattern's impact on insulin sensitivity in subjects without type 2 diabetes. A randomized trial ancillary to the PREMIER (Prospective Registry Evaluating Myocardial Infarction: Events and Recovery) blood pressure study10 of 52 subjects revealed that the DASH eating plan was beneficial for improving a variety of factors in the metabolic syndrome, including blood pressure, lipid levels, and insulin resistance. The authors concluded that the addition of the DASH eating plan led to statistically significant improvements in insulin sensitivity compared to the control group.
However, the ENCORE (Exercise and Nutritional Interventions for Cardiovascular Health) trial,11 a randomized, controlled trial conducted with 144 hypertensive subjects, showed different results. This trial suggested that the DASH eating plan alone may help to reduce blood pressure in hypertensive individuals who are overweight but may not significantly improve insulin sensitivity unless combined with a lifestyle-modification program that includes exercise and weight reduction.
Table 2 provides an overview of these three studies and their key results.
Practical Applications of the DASH Eating Pattern for Diabetes Management
When working with patients who have diabetes, it is important to find an eating plan that can be tailored to patients' individual needs to help them meet their goals for glycemia, blood pressure, lipids, and weight control. A survey conducted in 2011 by the Academy of Nutrition and Dietetics revealed that, although patients are seeking more information about nutrition, there are several key barriers to healthier eating. The barriers cited include a desire not to give up favorite foods, time required to track food choices, a need for more practical tips, and a lack of understanding about nutrition guidelines.12
The DASH eating plan may be a beneficial starting point for many patients because it provides guidelines and tools to overcome all of these barriers. Even modest changes can be a step in the right direction; research has shown that few Americans follow eating patterns that even modestly equate with the DASH recommendations.13 As with implementing any food-choice and eating-pattern changes for diabetes management, it is important to consider how patients are currently managing their diabetes, including pharmacological therapies and previous meal-planning experience. Because the DASH eating plan is widely recommended, it may be an ideal way to assist patients as they work to incorporate a variety of nutritious foods to achieve all of their goals.
In addition to blood pressure, lipid, and glucose control, weight management is often a goal for patients with diabetes; indeed, 28% of individuals with type 2 diabetes are overweight (as defined by a BMI of 25–29.99 kg/m2), and 59% are obese (having a BMI ≥ 30 kg/m2).14 Although the DASH eating plan was not specifically designed for weight loss, weight reduction can be achieved by adjusting the recommended number of servings per food group to achieve caloric reduction.
Table 3 provides a 1-day sample menu based on the DASH guidelines for servings from each group and a daily sodium limit of < 2,300 mg. It is based on ~ 1,600 calories, a caloric intake that would assist many patients in achieving a healthy weight. This meal plan is written to include ~ 45–60 g carbohydrate per meal and 15–30 g carbohydrate per snack to assist with glycemic control. By adjusting the number of servings from each food group, this eating plan can be adjusted to meet individual needs for both carbohydrates and calories. For patients in need of additional tips, tools, recipes, and sample meal plans, a printable guide to the DASH eating plan is available online at http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/new_dash.pdf.5
Other considerations that may be helpful when implementing the DASH eating plan include making simple replacements such as choosing whole grain foods to increase fiber in place of more refined options and replacing sweets and desserts with fruits or vegetables that offer benefits for blood pressure control, overall nutrient intake, and, often, a lesser impact on blood glucose levels.
The DASH eating recommendations may be used as a starting point as a meal-planning tool; however, adjustments and timing of certain foods such as grains, fruits, and low-fat dairy foods may be necessary to ensure consistent carbohydrate intake throughout the day or appropriate timing of meals with insulin or other pharmacological therapies. Because the DASH eating plan may be more effective when combined with exercise and other lifestyle modifications, encouraging patients to adopt an active lifestyle may further improve their outcomes.8
Conclusion
Diabetes management involves controlling of a variety of metabolic factors. The DASH eating plan is one option that has been shown effective in hypertension management and diabetes prevention and that also can be implemented as a tool for managing diabetes. As with any strategy for effective diabetes management, patients must be at the center of the care team, and diabetes practitioners must work with them to implement individualized therapies that they are able to achieve. In general, when it comes to improving the eating habits of people with diabetes, even small changes can have a substantial impact on achieving diabetes management targets and overall health.
