Heart-healthy diets: Evidence favors Mediterranean, DASH, plant-based options over keto, intermittent fasting
The Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) diet and plant-based diets remain the three best options for preventing cardiovascular disease (CVD), according to new data published in Vascular Health and Risk Management.[1]
On the other hand, the keto diet and intermittent fasting are both associated with certain benefits, but more data is still needed to gain a better understanding of their long-term impact.
The study’s authors reviewed the science behind many of today’s most popular diets, using more than 150 references to support their assessment.
“Despite the advances in medical management and evidence-supported dietary interventions for improved heart health, cardiovascular disease remains the leading cause of death in the United States,” wrote first author Alaa Diab, MD, with the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health, and colleagues. “Over time, various diets have been studied for their effectiveness in CVD prevention.”
Diab et al. noted that the Mediterranean diet, DASH diet and healthy plant-based diets are the three dietary patterns supported by the most evidence when it comes to CVD prevention.
The Mediterranean diet
The Mediterranean diet, named after its connection to the eating habits typically found in Greece and Italy, is based on eating whole grains, fruits, vegetables, legumes, nuts, seeds and extra virgin olive oil. Many studies over the years, including randomized controlled trials, have shown that this diet is associated with significant cardiovascular benefits. The extra virgin olive oil appears to play a key role, due in parts to its “anti-inflammatory and antioxidant effects.”
Also, the team noted, the Mediterranean diet’s focus on high-fiber foods appears to benefit a patient’s gut microbiome.
“With improvement in the biodiversity of the gut microbiome … beneficial effects of blood pressure control, reduction in metabolic syndrome and diabetes, lower levels of pro-atherogenic compounds, and ultimately lower rates of CVD have been demonstrated,” the authors wrote.
The DASH diet
The DASH diet was designed to lower blood pressure and improve overall heart health. It prioritizes foods heavy in potassium, calcium and magnesium, limiting foods high in sodium, saturated fat and added sugars. Fruits, vegetables, whole grains, fish, poultry and nuts are all included in a well-balanced DASH diet.
“Significant reduction in cardiometabolic risk is seen with the DASH diet by lowering blood pressure, total cholesterol, and LDL-C, all of which are significant risk factors which are accounted for in the atherosclerotic CVD risk score and eventually lead to improvement in cardiac function and decreased incidence of diabetes,” the authors wrote. “One of the main key elements of the DASH diet in lowering blood pressure is the sodium restriction in comparison to other diets.”
Healthy plant-based diets
The group noted that different types of plant-based diets exist, including vegetarian, vegan and even lacto-vegetarian options. While these diets have been linked to key cardiovascular benefits, it is important to remember that simply excluding meat does not automatically make it a healthy option.
“These diets are assessed based on the vegetable content of the diet, but do not necessarily account for the sugar, fat and sodium content, which can decrease the cardioprotective nature of a plant-based diet,” the authors wrote. “Indeed, unhealthy plant-based diets (such as those higher in refined grains, potatoes/fries, juices/sweetened beverages, sweets) may have similar CVD risk as animal-based diets.”
It is also worth remembering that some individuals following a vegan diet may require B12 supplements.
Keto-like diets and intermittent fasting
High-fat, low carbohydrate keto diets have been linked to weight loss and other benefits for patients with type 2 diabetes, but these diets have also been associated with certain concerning effects, including increases in total cholesterol and LDL-C.
“The effect of a ketogenic diet on LDL-C is inconsistent, but some patients can have a very dramatic increase in LDL-C in response,” the authors wrote. “This dramatic increase in LDL-C levels can possibly exacerbate development of hyperlipidemia if an underlying genetic predisposition is present. Furthermore, a recent meta-analysis found the ketogenic diet conferred unfavorable effects on LDL-C, apoB, and total cholesterol in normal-weight adults.”
Intermittent fasting generally uses long periods of fasting between meals to prompt a state of ketosis. The most common examples of intermittent fasting focus on alternative day fasting and time restricted eating.
These diets “hold promise for cardiovascular health,” according to the researchers, but “the evidence is still limited.” One trend seen in recent research has been that these diets can be beneficial over a short-term basis, but those benefits may fade over time. Again, more research is still needed to learn more about these dietary options.
Diab et al. also highlighted key guidelines published by the American Heart Association [2] and American College of Cardiology [3] that focus on following a heart-healthy diet.
“These guidelines recognize the importance of healthy dietary patterns, rather than focusing on individual foods or nutrients, and recommend healthy nutrition to begin early in life,” the authors wrote.
Other co-authors for the evaluation were L. Nedda Dastmalchi, DO, MA, with the division of cardiology at Temple University Hospital; Martha Gulati, MD, a preventive cardiologist with Cedars-Sinai; and Erin Donnelly Michos, MD, director of women’s cardiovascular health research and associate professor of medicine at Johns Hopkins Medicine.
Gulati was recently honored by the Society of Cardiovascular Computed Tomography for her years of research on CVD in women and other topics related to preventive cardiology. Michos serves as co-editor-in-chief of the American Journal of Preventive Cardiology.
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Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.