Confused about the best diet for heart health? With the rise of various dietary patterns, it can be challenging to distinguish fact from fiction when it comes to heart-healthy eating.
The American Heart Association’s new scientific statement evaluates 10 popular diets for their alignment with heart-healthy eating guidelines.
In recent years, there has been an exponential increase in the variety of popular dietary patterns, leading to a concerning surge of misinformation circulating on social media platforms. This overwhelming influx of conflicting information has created a critical level of confusion among the general public and even healthcare professionals regarding heart-healthy eating. Many individuals may find themselves unsure about which dietary approach to follow, lacking the necessary time and expertise to evaluate the various options available.
Recognizing the urgent need for clarity, the American Heart Association (AHA) has released an informative report that aims to bridge this knowledge gap. The primary objective of this report is to serve as a valuable tool for clinicians and the public alike, enabling them to comprehend and discern which diets truly promote optimal cardiometabolic health.
Cardiometabolic health encompasses a cluster of elements that influence the body’s metabolism, encompassing the intricate processes involved in nutrient breakdown, tissue maintenance, and normal bodily function. Additionally, it encompasses the risk factors associated with heart and vascular diseases. These factors consist of blood glucose levels, cholesterol and other lipid profiles, blood pressure, and body weight. While elevated levels of a single factor can heighten the risk of heart disease, the presence of abnormalities in multiple factors further escalates the risk, leading to potentially more severe forms of the disease.
The Assessment: Ranking Well-Known Diets According to the American Heart Association’s Dietary Guidance
The American Heart Association (AHA) has evaluated various popular dietary patterns to determine how closely they align with their Dietary Guidance, a comprehensive set of guidelines aimed at improving cardiometabolic health. This guidance emphasizes the importance of limiting unhealthy fats and reducing the consumption of excessive carbohydrates. Such a balance optimizes both cardiovascular and overall metabolic health while also mitigating the risks associated with conditions like Type 2 diabetes and factors like obesity, which can stem from the overconsumption of carbohydrates, particularly processed carbs and sugary beverages. These factors are known to increase the risk of cardiovascular disease.
In a pioneering scientific statement, the AHA examines the degree to which prevalent dietary patterns adhere to these ten key features outlined in their guidance.
Scientific Assessment Identifies 10 Distinct Long-Term Dietary Patterns
- DASH-Style: A Heart-Healthy Approach Emphasizing Plant-Based Foods and Lean Proteins. The Nordic and Baltic diets are other types of this eating pattern.
- Mediterranean-Style: A Nutrient-Rich Diet with Focus on Plant Foods, Healthy Fats, and Moderate Wine Consumption
- Vegetarian-Style/Pescatarian: Plant-Based Eating including Fish
- Vegetarian-Style/Ovo-Lacto: Plant-Based Eating including Eggs and Dairy
- Vegetarian-Style/Vegan: A Plant-Based Diet Excluding All Animal Products
- Low-Fat: A Balanced Diet Restricting Fat Intake to Less Than 30% of Total Calories
- Very Low-Fat: Extreme Fat Limitation Below 10% of Total Calories, Including Vegan Options
- Low-Carbohydrate: Diet Regimens Reducing Carbohydrate Intake to 30-40% of Total Calories
- Paleolithic: Eliminating Grains, Legumes, Oils, and Dairy from the Diet
- Very Low-Carbohydrate/Ketogenic: Severe Carbohydrate Restriction Below 10% of Daily Calories
Evaluating Diets for Heart Health: Insights from New American Heart Association’s Scientific Report
In the evaluation of each diet against the American Heart Association’s (AHA) heart-healthy eating pattern, nine out of ten features were considered. The exception was “eating to achieve a proper energy balance to maintain a healthy weight,” as it depends on factors beyond diet choices, such as physical activity level, and applies uniformly to all diet categories. The diets were assessed based on how well their defining features aligned with AHA’s guidance, with scores of 1 for full compliance, 0.75 for substantial compliance, and 0.5 for partial compliance. Components not meeting the guidance received zero points. The scores were then totaled and adjusted, resulting in a rating between 0 and 100, where 100 represented the closest adherence to AHA’s dietary guidance.
Importantly, the evaluation did not include commercial dietary programs like Noom or Weight Watchers, diets designed for short-term use (less than 12 weeks), intermittent fasting or time-restricted eating practices, or diets intended for managing non-cardiovascular conditions such as gastrointestinal issues, food allergies, or intolerances.
The analysis revealed substantial variation in the alignment of the reviewed dietary patterns with AHA’s guidance, with scores ranging from 31 to 100. These scores were grouped into four tiers, highlighting the aspects of each diet that contributed to adherence to AHA’s guidance, as well as potential challenges in following them. Interestingly, the only element present in every diet pattern was the recommendation to minimize the consumption of foods and beverages with added sugars. The report also identifies opportunities to further enhance the healthful aspects of each eating pattern.
Tier 1: Top-rated Dietary Plans (Scoring above 85)
Among the highest-rated eating plans, four patterns stand out for their flexibility and diverse selection of wholesome foods. The DASH-style eating pattern earns a perfect score, meeting all of the Association’s guidelines. These eating patterns prioritize foods low in salt, added sugar, alcohol, tropical oils, and processed foods, while emphasizing non-starchy vegetables, fruits, whole grains, and legumes. Protein sources mainly consist of plant-based options like legumes, beans, and nuts, as well as fish or seafood, lean poultry and meats, and low-fat or fat-free dairy products.
Another highly regarded dietary plan is the Mediterranean-style diet.
Although it doesn’t specifically address added salt and permits moderate alcohol consumption instead of avoiding or limiting alcohol entirely, it still receives a slightly lower score than DASH.
Moreover, most aspects of a vegetarian eating pattern align well with the AHA’s dietary guidance. Pescatarian and vegetarian eating plans that incorporate eggs, dairy, or both also make it to the top tier of recommended diets.
“If [the Mediterranean-style diet] implemented as intended, the top-tier dietary patterns align best with the American Heart Association’s guidance and may be adapted to respect cultural practices, food preferences and budgets to enable people to always eat this way, for the long term,” said Christopher D. Gardner, Ph.D., FAHA, chair of the writing committee for the new scientific statement and the Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California.
Tier 2: Vegan and Low-Fat Diets (Scores 75-85)
Vegan and low-fat diets, which score between 75 and 85, share common features such as a focus on consuming vegetables, fruits, whole grains, legumes, and nuts. These diets also encourage limited alcohol intake and discourage the consumption of foods and beverages with added sugar. However, it is important to note that the vegan eating pattern may pose challenges for long-term adherence, particularly when dining out. Additionally, following a vegan diet may increase the risk of vitamin B-12 deficiency, which can lead to anemia due to red blood cell abnormalities. In such cases, healthcare professionals may recommend vitamin B-12 supplementation.
Low-fat diets typically treat all fats as equal, but the guidance from the Association suggests substituting saturated fats with healthier alternatives like mono- and polyunsaturated fats. Individuals who adhere to a low-fat diet may tend to consume excessive amounts of less healthy carbohydrates, such as refined grains and added sugars. However, with proper counseling and education, these potential issues can be addressed and mitigated for individuals interested in pursuing these eating patterns.
Tier 3: Moderately Aligned Diets (Scoring 55-74): Balancing Fat and Carbohydrate Intake
Scientific assessments indicate that dietary patterns falling within Tier 3 demonstrate moderate alignment with the guidance provided by the Association.
Many individuals are drawn to very low-fat diets, often of a vegan nature, due to their potential to decelerate the progression of arterial plaque formation. Similarly, evidence reveals that a healthy low-carbohydrate eating pattern can positively impact weight loss, blood pressure, blood sugar, and cholesterol levels, comparable to a healthy low-fat diet. However, it is important to note that both of these approaches limit the intake of food groups that the Association emphasizes in its recommendations.
The main drawback of very low-fat diets lies in their restriction of nuts and healthy plant oils (excluding tropical varieties). Such limitations may result in deficiencies of vital nutrients, including vitamin B-12, essential fatty acids, and protein, potentially leading to anemia and muscle weakness.
On the other hand, low-carbohydrate diets restrict the consumption of fruits (due to their sugar content), grains, and legumes. In reducing carbohydrate intake, individuals tend to consume less fiber while increasing saturated fat from animal-based products and meats—both of which contradict the Association’s guidance.
Considering the available evidence, it is suggested that modifying the restrictions on certain food groups, such as incorporating fruits, whole grains, legumes, and seeds, may aid individuals in adhering to a lower carbohydrate eating pattern, while simultaneously promoting long-term heart health. It is important to strike a balance that aligns with the Association’s recommendations.
Tier 4: Paleolithic and Very Low-Carb/Ketogenic Diets: Misalignment with Dietary Guidance (Scoring below 55)
Paleolithic and very low-carb/ketogenic diets, commonly employed for weight loss purposes, do not align well with the dietary recommendations set forth by the Association. The main strengths of very low-carb eating patterns lie in their emphasis on consuming non-starchy vegetables, nuts, and fish, while minimizing the intake of alcohol and added sugar. Short-term studies, lasting up to 6 months, have demonstrated improvements in body weight and blood sugar levels with these diets. However, after one year, most of the observed improvements were comparable to those achieved with less restrictive dietary approaches. These diets impose restrictions on the consumption of fruits, whole grains, and legumes, potentially leading to a reduction in fiber intake. Moreover, they tend to be high in fat, without adequate limitations on saturated fat. Consuming excessive amounts of saturated fat and inadequate fiber levels have both been associated with an increased risk of cardiovascular disease.
“There really isn’t any way to follow the Tier 4 diets as intended and still be aligned with the American Heart Association’s Dietary Guidance,” Gardner added. “They are highly restrictive and difficult for most people to stick with long term. While there will likely be short-term benefits and substantial weight loss, it isn’t sustainable. A diet that’s effective at helping an individual maintain weight loss goals, from a practical perspective, needs to be sustainable.”
In the quest to understand the efficacy of different dietary patterns, researcher Gardner emphasizes the prevalence of conflicting information arising from studies of the same diet. He observes that popular eating patterns are frequently misunderstood and not consistently followed as intended. This poses a significant challenge when assessing the true impact of a ‘diet as intended’ versus a ‘diet as followed.’ Seemingly contradictory research findings may simply indicate variations in adherence levels between studies, with one demonstrating high adherence while the other exhibits low adherence.
Source: 10.1161/CIR.0000000000001146
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