Digging In: Adherence to Plant-Based Diets Linked to Fewer HF Hospitalizations

People who follow a mostly plant-based diet are less likely to be hospitalized for heart failure (HF), according to data from the nationwide REGARDS study. While the researchers looked at a variety of dietary styles, ranging from mostly convenience foods or sweets to high consumption of fried food and alcohol, they stress that it is commitment to the plant-based lifestyle, not just occasionally eating that way, that appears to be most strongly associated with a protective effect.

“Many people think we were comparing these diets, but in fact we put each person into a quartile based on how they answered food frequency questionnaires,” said Kyla Lara, MD (Mayo Clinic, Rochester, MN), the study’s lead author. “They were not strictly placed in one dietary pattern. We were interested in: which one did they adhere to most?”

For example, people who self-reported being most adherent to a plant-based diet of cruciferous and other vegetables, fruit, beans, and fish had a 41% lower risk of heart failure hospitalization over the median 8.7 years of follow-up compared with people who were least adherent to that dietary style (P = 0.004). Conversely, people who reported being most adherent to a Southern diet comprised of fried food, organ meats, processed meats, eggs, added fats, and sugar-sweetened drinks had a 72% higher risk of heart failure hospitalization than those who were least adherent to a Southern diet (P = 0.005). When the researchers broke heart failure down into preserved (HFpEF) or reduced ejection fraction (HFrEF), however, only the latter was increased with the Southern diet.

The findings were published online yesterday ahead of print in the Journal of the American College of Cardiology.

For the REGARDS study, 16,608 adults with no history of cardiovascular disease completed a 150-question survey based on 107 food items, which were categorized into five diet styles:

• Plant-based—vegetables, fruit, beans, fish
• Southern—fried food, processed meats, eggs, added fats, sugar-sweetened beverages
• Convenience—meat, pasta, Mexican dishes, pizza, fast food
• Sweets/fats—desserts, bread, sweet breakfast foods, chocolate, other sugar
• Alcohol/salads—wine, liquor, beer, leafy greens, salad dressing

Over the follow-up period, there were 133 hospitalizations for HFpEF and 157 hospitalizations for HFrEF. After adjustment for a variety of societal, geographic, and comorbid factors, high adherence to a plant-based diet remained protective against heart failure hospitalization, but the Southern diet was no longer associated with increased risk. Lara and colleagues say this implies that “the Southern dietary pattern may increase the risk of HF through a variety of factors associated with obesity, visceral adiposity, hypertension, dyslipidemia, and chronic kidney disease.” Of the other dietary patterns—convenience, sweets/fats, and alcohol/salads—none showed an association with heart failure hospitalization.

Lara and colleagues hypothesize that the antioxidants and anti-inflammatories conferred through high adherence to a plant-based diet are likely contributors to the lower risk of heart failure.

A Step Closer to Precision Dietary Prevention

In an editorial accompanying the study, Dong D. Wang, SCD, MD (Harvard T.H. Chan School of Public Health, Boston, MA), notes that it appears to be the first to describe dietary habits in association with subtypes of heart failure.

“The differential associations of dietary patterns with the 2 HF subtypes were mechanistically plausible,” he writes. “These findings, if confirmed in future studies, will not only contribute to in-depth biological understanding and phenotypic refinement of HF, but also inform dietary prevention approaches customized for specific HF phenotypes.”

But Wang notes that the methods used in the study could have been more precise with regard to measuring eating habits. If they had been, “it is likely that the observed association between dietary patterns and HF risk would become stronger,” he adds.

Wang observes that while the study contributes to efforts to understand how precision medicine and precision dietary prevention could be used in heart failure, much remains to be explained, particularly with regard to the “large proportion of variability in clinical manifestations of HF, especially HFpEF.”

To TCTMD, Lara said despite the time constraints that physicians face when seeing patients, it is becoming clearer based on this study and others that conversations about the things people eat and how frequently they eat them need to be taking place regularly during patient visits.

“Even just taking 3 minutes to ask ‘What did you eat yesterday from the beginning of the day to the end of the day?’ [can be done] when you’re refilling their scripts for blood pressure medication,” she said. “Make it a point to discuss one change and make patients more aware of what their eating. And, if their insurance allows it, have them see a nutritionist.”

Importantly, Lara said it is not uncommon for physicians to feel ill-equipped to have some of these discussions because even contemporary medical school programs fail to keep pace with the need for formal nutrition training beyond simple advice such as reducing salt and following a Mediterranean diet.

“Nutrition education is the next wave of where our focus is going to be in terms of preventative medicine,” she added, noting that physicians need support to counter misconceptions about plant-based diets, such as patients thinking they will have to subsist on raw vegetables. Finally, she noted that being culturally sensitive and eliminating “food deserts” in certain areas of the country is another hurdle that physicians cannot tackle alone and one that will require education and other initiatives to provider wider access to healthy food items.