New study reveals the best diets for a healthy heart

In a recent study published in the journal Vascular Health and Risk Management, researchers discuss the various non-traditional and traditional practices, as well as the socioeconomic and food insecurity-related limitations associated with adopting diets for heart health.

Study: A Heart-Healthy Diet for Cardiovascular Disease Prevention: Where Are We Now? Image Credit: New Africa / Shutterstock.com

Background

Despite considerable progress in medicine and dietary interventions that have improved cardiovascular health, cardiovascular disease remains one of the most prevalent causes of mortality in the United States.

Early studies on the association between diet and cardiovascular health reported that a diet rich in fish, vegetables, grains, fruits, and beans was linked to a lower rate of myocardial infarctions. Moreover, the consumption of vegetables and fruits, along with regular exercise, was associated with 40% lower rates of myocardial infarction.

Hypertension, excess abdominal fat, dyslipidemia, and type 2 diabetes are some of the risk factors for cardiometabolic diseases that can be modified through changes in the diet. In the U.S., the prevalence of type 2 diabetes, blood pressure, and obesity have been on the rise, thus increasing the risk of cardiovascular diseases. Abdominal waist circumference has also become a cardiovascular disease marker.

Growing scientific evidence indicates that the Dietary Approaches to Stop Hypertension (DASH), Mediterranean, and other largely plant-based diets are associated with cardioprotective properties and the ability to modify the gut microbiome.

Heart healthy diets

The Mediterranean diet comprises fruits, leafy green vegetables, nuts, legumes, spices, herbs, lean meat such as fish and poultry, as well as extra virgin olive oil. Additionally, this diet recommends moderate consumption of alcohol, as well as limited sweets and red meat intake. The Mediterranean diet eliminates processed or refined sugars and grains, saturated fats, and large amounts of red meat.

The Mediterranean diet has been found to reduce inflammation, alter the gut microbiome, modulate the expression of pro-atherogenic genes, and improve lipid profiles. In individuals genetically susceptible to cardiometabolic diseases, the Mediterranean diet was found to reduce the adverse phenotypes associated with cardiometabolic health and decrease the expression of pro-atherothrombotic genes.

The DASH diet primarily consists of vegetables, fruits, whole grains, fish, poultry, low-fat dairy products, seeds, and nuts. Similarly, this diet recommends avoiding sugar-sweetened beverages, fatty meats, and full-fat dairy products.

The DASH diet also recommends that daily salt consumption be maintained under 2,300 mg. Notably, this diet has been associated with significantly lower blood pressure levels in patients with hypertension, as well as a reduced risk of diabetes, heart failure, and cardiovascular disease.

Healthy plant-based diets, including vegetarian and vegan diets, predominantly include plant products. However, subsets of these diets include lacto-vegetarians, lacto-ovo-vegetarians, pescatarians, and semi-vegetarians, who, along with plant-based foods, also consume various combinations of dairy products, eggs, or fish.

Although healthy plant-based diets focus on the consumption of whole grains, vegetables, fruits, legumes, and nuts, most subsets do not strictly recommend a lower consumption of salt, fats, or sugars, which could reduce the cardioprotective effects of the diet.

Controversial or emerging diets

The ketogenic diet comprises a high intake of fats, moderate protein intake, and very low consumption of carbohydrates.

The ketogenic diet has successfully helped people lose weight, as well as improve their glycemic control and insulin resistance. However, a high-fat diet can increase the levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, total apolipoprotein B, and non-high-density lipoprotein cholesterol, all of which are linked to an increased risk of cardiovascular disease.

Intermittent fasting is another emerging dietary pattern that recommends prolonged periods of fasting to activate ketosis. While intermittent fasting has shown promise as an approach to weight loss, long-term studies on the impact of intermittent fasting on cardiovascular health are lacking. Furthermore, no clinically significant reductions in the risk factors associated with cardiometabolic health have been observed.

Cardiovascular health and the gut microbiome

Emerging research indicates that pre- and pro-biotics alter the gut microbiome with potential impacts on cardiovascular health. The use of probiotics has been linked to a mild decrease in blood glucose levels and blood pressure, while high-fiber diets have been associated with an increase in gut microbiome diversity and a lower risk of cardiovascular disease and hypertension.

Challenges in adopting heart-healthy diets

Cultural and social factors, as well as socioeconomic status, are generally associated with incompatibility to adhering to a heart-healthy diet. Social barriers prevent ethnic and gender-related minorities, as well as underserved populations, from accessing heart-healthy diets, which results in a higher incidence of cardiovascular disease and mortality among these populations.

Food insecurity, a lack of grocery stores that provide fresh produce, and the excess availability of poor-quality ultra-processed foods also contribute to increased obesity and cardiovascular diseases. Some studies have reported that the coronavirus disease 2019 (COVID-19) pandemic exacerbated food insecurity among the lower socioeconomic classes, thereby resulting in an increase in the consumption of cheaper, highly processed meats and sugar-sweetened beverages.

Conclusions

The current study suggests that the Mediterranean diet provides the most cardioprotective effects, with the DASH and healthy plant-based diets with low salt and sugar content also considered heart-healthy. The impact of certain diets, such as the ketogenic diet and intermittent fasting on cardiovascular health remains controversial or unclear.

Written by

Dr. Chinta Sidharthan

Chinta Sidharthan is a writer based in Bangalore, India. Her academic background is in evolutionary biology and genetics, and she has extensive experience in scientific research, teaching, science writing, and herpetology. Chinta holds a Ph.D. in evolutionary biology from the Indian Institute of Science and is passionate about science education, writing, animals, wildlife, and conservation. For her doctoral research, she explored the origins and diversification of blindsnakes in India, as a part of which she did extensive fieldwork in the jungles of southern India. She has received the Canadian Governor General’s bronze medal and Bangalore University gold medal for academic excellence and published her research in high-impact journals.