Uncontrolled hypertension is a growing public health concern, affecting millions worldwide. The Dietary Approaches to Stop Hypertension (DASH) diet has emerged as an effective strategy for lowering blood pressure (BP) through dietary modifications. With the proliferation of smartphones, numerous apps have been developed to support self-management of the DASH diet. This article provides a comprehensive review of DASH diet apps, evaluating their effectiveness, quality, security, and potential to improve adherence and reduce BP.
Understanding Hypertension and the DASH Diet
Hypertension, or high blood pressure, is a serious medical condition that significantly increases the risk of heart failure, stroke, kidney failure, and other life-threatening complications. Globally, over a billion people suffer from hypertension, highlighting the urgent need for effective management strategies.
Risk factors for hypertension include modifiable factors such as unhealthy diet, physical inactivity, obesity, tobacco and alcohol consumption, as well as nonmodifiable factors like family history, age, and chronic diseases. Self-management plays a crucial role in controlling hypertension, empowering individuals to take charge of their health.
The DASH diet, established by the National Heart, Lung, and Blood Institute (NHLBI), offers a balanced and healthy dietary approach to lower BP. It emphasizes the consumption of vegetables, fruits, whole grains, fish, poultry, beans, nuts, and healthy oils, while limiting sodium, sugar, and saturated fats. Studies have demonstrated that adherence to the DASH diet can lead to a significant reduction in BP, with mean differences ranging from -3.20 mmHg to -7.62 mmHg for systolic blood pressure (SBP) and from -2.50 mmHg to -4.22 mmHg for diastolic blood pressure (DBP).
In addition to lowering BP, the DASH diet has also been linked to a decreased risk of cardiovascular diseases, improved insulin resistance, and weight management. However, adherence to the DASH diet remains low, underscoring the need for effective tools and strategies to support individuals in adopting and maintaining this healthy eating pattern.
Read also: Delicious DASH Diet Treats
The Role of Smartphone Apps in DASH Diet Self-Management
The widespread use of smartphones presents a unique opportunity to support the DASH diet through mobile apps. These apps can provide users with convenient access to information, tools, and resources to track their diet, monitor their BP, and promote healthy lifestyle changes.
This review synthesizes existing evidence on the effectiveness of smartphone apps in improving DASH diet adherence and reducing BP. It also assesses app usability, acceptability, user engagement, and satisfaction.
Methodology for Evaluating DASH Diet Apps
A comprehensive evaluation of DASH diet apps was conducted using a systematic approach. This involved searching electronic databases such as Embase (OVID), Cochrane Library, CINAHL, Web of Science, Scopus, and Google Scholar. The search included studies that used DASH smartphone apps to support self-management.
The review included studies that involved adults with prehypertension or hypertension, examining the use of mobile phone apps alone or combined with other components. The primary outcome measures were BP level and adherence to the DASH diet. Data was extracted and organized into logical categories, including clinical outcomes, DASH diet adherence, app usability and acceptability, and user engagement and satisfaction.
In November 2022, systematic searches were conducted in the UK within the iPhone (Apple App Store) and Android (Google Play) stores. Apps were identified using keywords such as 'DASH diet', 'high blood pressure diet', and 'hypertension diet'. Inclusion criteria required that the app allow users to track their diet intake, be written in English, and include the DASH diet in its description. Exclusion criteria encompassed apps not related to the DASH diet, those not meant for self-management, apps offering a variety of diets where DASH was not the primary focus, apps designed for professional use by doctors or dietitians, and apps for food sales or takeaway orders.
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Three reviewers used the App Quality Evaluation Tool (AQEL) to assess each app's quality across seven domains: knowledge acquisition, skill development, behavior change, purpose, functionality, and appropriateness for adults with hypertension. Two reviewers assessed the apps' data privacy and security and then coded Behavior change techniques (BCTs) linked to the Theoretical Domain Framework (TDF) underpinning the likely effectiveness of the apps.
Findings from Systematic Reviews
Several studies have explored the effectiveness of DASH diet apps. One systematic review of studies conducted between 2008 and 2021 examined DASH mobile apps. The review found that while all studies showed a positive trend related to the use of DASH smartphone apps, the RCTs had a high risk of bias. As a consequence, no firm conclusions could be drawn regarding the effectiveness of DASH smartphone apps for increasing DASH diet adherence and lowering BP. There is weak emerging evidence of a positive effect of using DASH smartphone apps for supporting self-management to improve DASH diet adherence and consequently lower BP.
Another study evaluated DASH diet self-management apps based on their quality, likely effectiveness, and data privacy/security to identify the most suitable app(s). The AQEL assessment showed that three apps scored higher than eight in most of the AQEL domains. Nineteen BCTs were used across the apps, linked to nine TDF action mechanisms that may support DASH diet self-management behaviors. Four apps met standards for privacy and security. All seven apps with self-monitoring functionality had sufficient theoretical basis to demonstrate likely effectiveness. However, most had significant quality and data security shortcomings.
Characteristics of Included Studies and Apps
The included studies had sample sizes ranging from 17 to 120 participants, with a total of 334 participants. Participants from all the studies ranged in age from 18 to 75 years. The studies aimed to enhance self-management with increased patient awareness through educational information. Some studies enhanced self-management without involving a human coach to monitor patients remotely, whereas the remaining studies aimed to enhance self-management by involving a human coach or research team to monitor patient data and health status remotely.
Each of the reviewed studies used a different app, with some apps commercially available and others developed specifically for the study. The apps varied in their features, functionalities, and theoretical frameworks.
Read also: The DASH Diet and Blood Sugar
Effectiveness of DASH Diet Apps on Blood Pressure and Adherence
Several studies reported a positive effect of the DASH diet app on both SBP and DBP, with some studies reporting significant results. These studies demonstrated that using a DASH app resulted in better adherence to the DASH diet and consequently lower BP.
For example, one study demonstrated that using a smartphone app to educate patients about the DASH diet and improve self-efficacy resulted in better adherence to the DASH diet, with significant differences between groups at the end of the trial. Another study evaluated the app’s impact on patient adherence to the DASH diet and observed increased consumption of fruits, vegetables, and dairy in the intervention group compared with the control group.
A study comparing dietary changes between women who used app-based diet tracking and those who used app-based diet tracking with feedback on DASH adherence through text messages found that both groups’ DASH scores improved significantly after 3 months. A single-unit increase in the DASH score in the intervention group was linked to a 2.7 mmHg drop in SBP and a 1.3 mmHg drop in DBP.
User Engagement, Satisfaction, and Acceptability
User engagement was assessed by logging food intake, BP, weight, and step count. Chats, phone calls, and text messages were also incorporated. In the studies that evaluated user satisfaction, participants were very accepting of the use of apps. Participants reported that the app was easy to use, and that they used it frequently and would recommend it to friends.
Quality, Security, and Behavior Change Techniques
Seven DASH diet apps were assessed, showing the limited availability of apps supporting DASH diet self-management. The AQEL assessment showed that three apps scored higher than eight in most of the AQEL domains. Nineteen BCTs were used across the apps, linked to nine TDF action mechanisms that may support DASH diet self-management behaviors. Four apps met standards for privacy and security. All seven apps with self-monitoring functionality had sufficient theoretical basis to demonstrate likely effectiveness. However, most had significant quality and data security shortcomings.
Examples of DASH Diet Apps and Features
Several apps are available to support the DASH diet, each with unique features and functionalities. Some examples include:
- Easy Recipes for Heart Health Free: This app offers hundreds of heart-friendly recipes, diet tips, and guidance. It combines meal plans with features for customizable ketogenic diet plans, recipe flexibility, and personalized diet counseling.
- SmartBP: This blood pressure measurement tool allows users to record, track, and analyze trends regarding their blood pressure. It integrates with Google Fit and Apple Health to provide a convenient way to visualize what is and isn’t working for blood pressure management.
- KardiaMobile: This app comes with an external EKG measurement device and bills itself as "the most clinically‑validated personal EKG in the world."
- QardioArm: This compact cuff pairs with an iOS or Android app to provide quick and accurate blood pressure readings.
- Instant Heart Rate: This app transforms a phone’s camera lens into a heart rate monitor, displaying a reading in less than 10 seconds.
- CardioVisual: This educational app features bountiful libraries of health information for almost every heart condition.
- Calm: This app promotes stress management through guided meditation, relaxing music and sounds for sleep, videos on mindful movement and stretching, mindfulness classes, and images of nature.
- PulsePoint Respond: This app connects users with CPR-trained people in their community who are ready to act in a cardiac emergency.
Risk Factors for Developing High Blood Pressure
Several risk factors can contribute to the development of high blood pressure, including:
- Age: The risk of developing high blood pressure increases with age.
- Tobacco Use: Tobacco use can damage the walls of arteries and increase the risk of high blood pressure.
- Alcohol Use: Binge-drinking or over consumption of alcohol can cause heart damage and affect blood pressure.
- Stress: Stress can cause temporary spikes in blood pressure and may be comorbid with other risk factors.
- Physical Activity: Inactivity can lead to obesity and increase the heart's workload.
- Salt: An increase in salt intake can cause blood pressure to rise.
What Constitutes High Blood Pressure?
According to the CDC, high blood pressure or hypertension, is considered when blood pressure readings are consistently higher than normal. Normal blood pressure, according to the American Heart Association, is when your systolic reading is less than 120mmHg and your diastolic is less than 80mmHg.
DASH Diet Meal Planning: What to Eat
The DASH diet does not recommend specific meal plans but provides recommendations for different food groups to allow for flexibility and individualization. The diet typically recommends limiting salt intake to no more than 1 teaspoon daily.
The DASH diet typically recommends the following daily servings:
- Whole Grains: 6 to 8 Servings
- Vegetables: 4 to 5 Servings
- Fruits: 4 to 5 Servings
- Dairy: 2 to 3 Servings
- Lean Meat: 6 or Fewer Servings Weekly
- Nuts, Seeds, Legumes: 4 to 5 Servings Weekly
- Fats and Oils: 2 to 3 Servings
- Added Sugars: 5 or Fewer Weekly
Other Potential Benefits of the DASH Diet
In addition to lowering blood pressure, the DASH diet can offer other potential benefits, including:
- Aids Weight Loss: By cutting out high-fat and sugary foods, the DASH diet can contribute to weight loss.
- Lowers Your Risk of Diabetes: Lowering blood pressure with the DASH diet can help reduce the risk of developing Type 2 diabetes.
- Lowers Your Risk of Heart Disease: By lowering blood pressure, the DASH diet can reduce the risk of developing heart disease.