Lower risk of incident hospitalization for HF with higher adherence to plant-based diet
Dietary Patterns and Incident Heart Failure in U.S. Adults Without Known Coronary DiseaseLiterature - Lara KM, Levitan EB, Gutierrez OM et al. - JACC 2019;83(16):2036-45
Introduction and methods
Limited data are available on the association of dietary patterns with incident heart failure (HF) in patients without coronary heart disease (CHD). Previous studies focusing on this association investigated specific food types, such as fried foods, eggs, and high-fat dairy [1,2]. Mediterranean diet and DASH (Dietary Approaches to Stop Hypertension) diet have been shown to be inversely linked to incident HF . However, these results are observed in populations lacking racial and ethnic diversity.
Within the REGARDS (REasons for Geographic and Racial Differences in Stroke) study population five major dietary patterns were empirically found: convenience, plant-based, sweets, Southern, alcohol and salad . The current study (n=16.068) investigated the link of these five dietary patterns with incident HF hospitalization (HHF) in REGARDS participants free of CHD or HF at baseline. In addition, the link of the dietary patterns and hospitalization for HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF) were examined separately.
The REGARDS trial is a national prospective cohort, including 30.239 black and white adults aged ≥45 years (recruited from Jan 2003-Oct 2007). Information on sociodemographic characteristics, CVD risk factors, and psychosocial characteristics was obtained via phone interviews. During a subsequent in-home visit, a trained health professional performed a physical evaluation and collected spot urine and fasting blood samples for analysis. Information on dietary patterns was self-reported using the Block 98 food frequency questionnaire (FFQ).
Participants received a score for each dietary pattern and were divided into quartiles based on adherence to each pattern (Q1 lowest adherence, Q4 highest adherence). Hospitalizations were self-reported during follow-up interviews and medical records were retrieved for adjudication. Adjudication of HHF was based on HF signs and symptoms, laboratory studies, electrocardiogram, and assessments of left ventricular function documented in the medical records. Median follow-up was 8.7 years.
Associations of dietary patterns with incident HHF
- Those who were most adherent to the plant-based dietary pattern (Q4) had 41% lower risk of incident HHF (HR: 0.59, 95%CI: 0.41-0.86), compared with the least adherent participants (Q1) (P-linear trend=0.004) in multivariable analyses.
- Subjects in Q4 of adherence to the Southern dietary pattern had 72% higher risk of HHF (HR: 1.72, 95%CI: 1.20-2.46), compared to those in Q1 (P-linear trend=0.005). However, this association lost significance after further adjustment for BMI, waist circumference (WC), hypertension, dyslipidemia, diabetes, AF, eGFR, albumin-to-creatinine ratio.
- Other dietary patterns were not significantly linked to risk of incident HHF.
Associations of dietary patterns with incident HHF stratified by HF subgroups
- The Southern dietary pattern was associated with a 97% higher risk of HFrEF hospitalization in Q4 (HR: 1.97, 95%CI: 1.13-3.43), compared to Q1 (P-linear trend=0.02). However, this association lost significance after further adjustment for BMI, WC, hypertension, dyslipidemia, diabetes, AF, eGFR, albumin-to-creatinine ratio.
Associations of dietary patterns with incident HHF stratified by risk factors
- Across subgroups with established risk factors, there were no significant interactions between dietary patterns and incident HHF.
This cohort study showed lower risk of incident HHF with higher adherence to plant-based dietary patterns (high intake of fruit, vegetables, fish, poultry, and low-fat dairy, and low consumption of soda) in a diverse population of American adults free of CHD, which was independent of established CVD risk factors. These data support a population-based dietary strategy to reduce risk of incident HHF.
In his editorial comment, Wang emphasizes the highlights of the study conducted by Lara et al.: the investigators have not only provided meaningful data supporting a population-based dietary strategy to reduce risk of incident HHF by inclusion of subjects who were free of CHD with a third being black, but they also reported about risk of incident HHF with different dietary patterns in HFrEF and HFpEF separately. Also, the five major dietary patterns have been empirically identified.
The current study is the first examining various dietary patterns in association with HF subtypes in epidemiological studies. Although findings were not significant, Wang went deeper in on the potentially different findings for HF types. In contrast to HFrEF, which is mainly caused by CHD and other myopathies with often cardiac injury as primary characteristic, HFpEF has systemic origins in most cases with cardiac injury as secondary characteristic. It may be that a plant-based diet with low energy density, high fiber and high antioxidant content modifies systemic risk factors underlying HFpEF. ‘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. In addition, they perfectly fit into key missions of precision medicine ’. However, Wang notes that more sufficiently powered studies are needed.
The study also includes some limitations: diet and covariates were measured only once while diets may have been changed over time by participants, there might have been residual bias due to the observational study design, and the follow-up duration was relatively short. Future research on dietary patterns and onset of HF should repeatedly collect data on dietary consumption and follow participants for a longer period.
Wang concludes that the current study provides important evidence for the dietary prevention of HF, with potentially different preventive dietary strategies for HFrEF and HFpEF patients. ‘Future epidemiological studies that include a more advanced disease classification through applying deep-phenotyping of large populations and the big data analytics would set the stage for the precision prevention of HF’.