back to notes

Do Plant-Based Diets Lower Heart Failure Risk?

https://www.medscape.org/viewarticle/913804?nlid=130423_2712&%20src=wnl_cmemp_190705_mscpedu_pharm&uac=105293CG&impID=2019192&faf=1


Authors: News Author: Batya Swift Yasgur, MA, LSW; CME Author: Laurie Barclay, MDFaculty and Disclosures

Clinical Context

Heart failure (HF) is a progressive chronic disease creating a considerable burden of morbidity, mortality, and healthcarecosts. Preventive strategies have addressed smoking, hypertension, and diet to prevent ischemic heart disease, but less isknown about dietary patterns and incident HF in persons without coronary heart disease (CHD).

This study evaluated associations of 5 dietary patterns with incident HF hospitalizations among US adults enrolled in theREGARDS (Reasons for Geographic and Racial Differences in Stroke) trial, a prospective cohort of black and white adults followedfrom 2003-2007 to 2014. The hypothesis tested by this study was that greater adherence to Southern and convenience dietarypatterns and lower adherence to a plant-based dietary pattern would be associated with incident HF.

Study Synopsis and Perspective

Plant-based diets are associated with a lower risk for incident HF in adults without known heart disease, new research suggests.

Researchers followed more than 16,000 adults (mean age, 64.0 years) with no known CHD or HF at baseline, comparing those whoadhered to a plant-based diet with those who consumed a Southern diet consisting of more fried and processed foods and sweeteneddrinks.

They found that the plant-based diet was associated with a 41% lower risk for incident HF with the highest vs lowest adherence,whereas the Southern diet was associated with a 72% higher risk for HF with higher vs lower adherence, after adjusting forpotential demographic, lifestyle, and medical confounders.

"The take-home message of our findings is to emphasize more vegetables [and] plant proteins like lentils, nuts, chickpeas, tofu, beans, etc, and limit consumption of meat; [this] is the future of health," lead author Kyla Lara, MD, postgraduate fellow of cardiology and general internal medicine, Icahn School of Medicine, Mount Sinai, New York City, told theheart.org | Medscape Cardiology.

"Educating patients on what these entail is the first step in changing the lifestyle of our patients," she said.

The study was published online April 22 and in the April 30 issue of the Journal of the American College of Cardiology.[1]

5 Dietary Patterns

HF is projected to affect more than 8 million people by 2030, necessitating a critical need for population-based preventivestrategies, the authors write.

Previous research has demonstrated inverse associations with incident hypertension in people adhering to the Mediterraneanor DASH (Dietary Approaches to Stop Hypertension) diets; however, these studies were "limited to participants from populationsthat lacked racial and ethnic diversity," the authors note.

"We wanted to look at dietary patterns in people without coronary disease or [HF] and see if we could find any associations,positive or negative, with the development of new [HF]," Dr Lara said.

"Our study focused on US American adults, both black and white, living in the stroke belt and continental US," she added.

The researchers drew on data from the REGARDS study, a national cohort study consisting of 30,239 black and white adults (aged ≥45 years) recruited from January 2003 to October 2007.

The researchers narrowed their sample size to 16,068 black and white participants (mean age, 64.0±9.1 years; 58.7% women, 33.6% black, 34.0% residents of the stroke belt) who were required to be free of HF and CHD at baseline.

Participants were asked to respond to a 150-question survey, based on 107 food items. From the responses, 56 food groups wereidentified, which were then categorized into 5 types of diets:
1.Convenience: heavily meat-based dishes, pasta, Mexican dishes, pizza, and fast food.
2.Plant-based: vegetables, fruits, beans, and fish.
3.Sweets/fats: heavily sugar- or fat-based food (eg, desserts, bread, sweet breakfast foods, chocolate, and other sugar).
4.Southern: heavy on fried food, processed meats, eggs, added fats, and sugar-sweetened beverages.
5.Alcohol/salads: heavy on wine, liquor, and beer, as well as leafy greens and salad dressing.

Measurements of blood pressure, height, weight, waist circumference, urine, and fasting blood samples were collected at baseline.

Participants received a score for each dietary pattern, and were then grouped into 1 of 4 quartiles of adherence to each pattern,with quartile 1 (Q1) being the lowest adherence and quartile 4 (Q4) representing the highest adherence to each.

Participants were interviewed every 6 months. In those who reported hospitalization, medical records were retrieved and adjudicatedon the basis of signs/symptoms of HF, laboratory studies, and assessment of left ventricular function documented in the medicalrecord.

Medical covariates included hypertension, dyslipidemia, diabetes, atrial fibrillation, and chronic kidney disease (CKD).

Participants were followed for a median of 8.7 years, with telephone interviews conducted every 6 months.

Anti-inflammatory Effects

There were 363 new HF hospitalizations during the follow-up period.

In the fully adjusted analyses, there was a 41% lower risk for new HF hospitalizations for participants who were most adherent(Q4) to the plant-based dietary pattern compared those who were least adherent (Q1).

In contrast, highest adherence (Q4) to the Southern dietary pattern was associated with a 72% higher risk for HF hospitalizationin models adjusted for age, sex, and race.

However, after further adjustment for other potential confounders (education, income, region of residence, total energy intake,smoking, physical activity, and sodium intake), the association between the Southern diet and incident HF risk was attenuatedand no longer statistically significant.

After multivariable adjustment, the researchers found no statistically significant associations among the remaining dietarypatterns.

When the researchers stratified HF hospitalizations by subtype, they identified 133 cases of HF with preserved ejection fraction(HFpEF), 157 cases of HF with reduced ejection fraction (HFrEF), and 73 cases of HF with intermediate EF or without documentedEF.

There was a 97% increased risk in adherents to the Southern dietary pattern for HFrEF, which was found to be statisticallysignificant.

In fully adjusted analyses that included potential mediating variables, however, there were no statistically significant associationsof the dietary patterns with incident HFrEF or HFpEF hospitalizations.

Inverse associations were observed in men and participants with an estimated glomerular filtration rate >60 mL/min/1.73 m2, body mass index <30 kg/m2, no history of diabetes, and past smoking history in Q4 of the plant-based dietary pattern. However, the interactions betweenthese subgroups were not found to be significant.

In contrast, a statistically significant interaction in the Southern dietary pattern was observed and showed a stronger positiveassociation with HF in participants <65 years of age.

Dr Lara emphasized that their study did not compare diets with one another but, rather, placed each participant in a quartilefor each of the dietary patterns, depending on how they answered the food frequency questionnaire.

"The Mediterranean diet is a much better option than the Southern dietary pattern, since it emphasizes healthy fats like oliveoil, nuts, avocadoes, and fish and recommends avoiding fried foods and red meat, which are central to the Southern diet,"she observed.

She suggested several potential reasons why a plant-based diet might be protective against HF.

"Current theories include the effects of antioxidants and anti-inflammatory effects, which are highly abundant in plant-baseddiets," she noted.

"Reactive oxygen species promote hypertrophy, aortic stiffness, [and] interstitial fibrosis, and can potentially decreasemyocardial contractility, all of which can contribute to the development of [HF]," she explained.

"On the other hand, plant antioxidants decrease the amount of reactive oxygen species, and with plant-based diets, we canalso see decreased serum concentrations of [C-reactive protein, interleukin 6,] and soluble intercellular adhesion molecule-1,which are inflammatory biomarkers," she added.

Dr Lara said that future research will focus on plant-based diets in patients entering cardiac rehabilitation, and will alsostart exploring the microbiome, plant-based diets, and cardiovascular health.

Improved Cardiac Outcomes

Commenting on the study for theheart.org | Medscape Cardiology, Robert Ostfeld MD, director, Preventive Cardiology, and founder and director, Montefiore Einstein Cardiac Wellness Program,Bronx, New York, who was not involved with the research, said the findings of this study "accord with my own clinical experience."

He reported that he has found "that the more one adopts a plant-based diet, the better the outcomes, including improving angina,reversing hypertension and diabetes, lowering cholesterol, and losing weight, among other improvements."

Dr Ostfeld, who is also an associate professor of medicine, Albert Einstein College of Medicine, Bronx, suggested multiplemechanisms that might account for these benefits.

"Minimally processed plant-based foods are rich in fiber, antioxidants, and phytonutrients, which can improve the health ofour microbiome, reduce inflammation, and reduce oxidative stress," he noted.

"Furthermore, by consuming a plant-based diet, one can avoid potentially harmful effects of animal-based foods, such as hemeiron, sialic acid, and cholesterol, among others," he added.

Also commenting on the study for theheart.org | Medscape Cardiology, Kim Allan Williams, MD, Sr, James B. Herrick Professor and chief, Division of Cardiology, Rush University School of Medicine, Chicago, Illinois, said that "[the researchers'] data is consistent with the finding that red meat and the [trimethylamine N-oxide] generated by eating this are associated with worsening [HF] incidence, recurrence, and mortality."

Dr Williams, who was not involved with the study, said that a plant-based diet has advantages over other heart-healthy dietsbecause it contains "less saturated fat, trans-fat, nitrates, nitrite [branched chain amino acids], heme-iron, cholesterol,and [trimethylamine N-oxide]."

In an accompanying editorial, Dong D. Wang, MD, from the Department of Nutrition, Harvard T.H. Chan School of Public Health,Boston, Massachusetts, said the study "represents an important step forward in establishing a robust evidence base for thedietary prevention of HF."[2]

"The authors' finding on the potentially differential associations of dietary patterns with HFpEF as compared with HFrEF providesan early glimpse of precision dietary prevention of HF (i.e., recommending dietary approaches customized to HF subtypes withdifferent pathophysiological basis)," Dr Wang writes. "However, to achieve the precision prevention of HF, much research isneeded to accrue robust and reproducible evidence. In addition, although the traditional classification into HFpEF and HFrEFwas proven to be useful in differentiating distinct pathophysiology with therapeutic implications, a large proportion of variabilityin clinical manifestations of HF, especially HFpEF, remains unexplained," Dr Wang notes. "Future epidemiological studies thatinclude a more advanced disease classification through applying deep-phenotyping of large populations and the big data analyticswould set the stage for the precision prevention of HF."

Dr Lara has disclosed no relevant financial relationships. The other authors' disclosures are listed on the original paper.Dr Wang, Dr Ostfeld, and Dr Williams have disclosed no relevant financial relationships.

J Am Coll Cardiol. Published online April 22, 2019.


Study Highlights
•The prospective cohort for the REGARDS trial consisted of black and white adults followed from 2003 to 2007 through 2014.
•There were 16,068 participants meeting inclusion criteria for this analysis of REGARDS data, which were completion of a foodfrequency questionnaire and no baseline CHD or HF.
•Mean age was 64.0±9.1 years, 58.7% were women, 33.6% were black, and 34.0% were residents of the stroke belt.
•Participants underwent baseline measurements of blood pressure, height, weight, and waist circumference; urinalysis; and testingof fasting blood.
•On the basis of principal component analysis of food frequency questionnaire data, the investigators scored participants oneach of 5 dietary patterns (convenience, plant-based, sweets, Southern, and alcohol/salads).
•The convenience pattern was high in meat-based dishes, pasta, Mexican dishes, pizza, and fast food, whereas the plant-basedpattern emphasized vegetables, fruits, beans, and fish.
•The sweets/fats pattern contained heavily sugar- or fat-based food, such as desserts, bread, sweet breakfast foods, chocolate,and other sugars; the Southern pattern was high in fried food, processed meats, eggs, added fats, and sugar-sweetened beverages;and the alcohol/salads pattern included larger amounts of wine, liquor, beer, leafy greens, and salad dressing.
•Incident hospitalization for HF was the main study endpoint, which occurred in 363 participants during follow-up (median,8.7 years, with telephone interviews every 6 months).
•For participants with HF hospitalization, medical records were reviewed for signs/symptoms of HF, laboratory findings, andleft ventricular function.
•Multivariable-adjusted models showed that the highest vs lowest quartile of adherence to the plant-based dietary pattern wasassociated with a 41% lower risk for HF (hazard ratio, 0.59; 95% confidence interval, 0.41-0.86; P=.004).
•This association was observed even among adults with baseline hypertension, which is a known risk factor for HF.
•After adjustment for age, sex, and race and for other potential confounders (education, income, region of residence, totalenergy intake, smoking, physical activity, and sodium intake), highest adherence to the Southern dietary pattern was associatedwith a 72% higher risk for HF (hazard ratio 1.72; 95% confidence interval, 1.20-2.46; P=.005).
•Further adjustment for body mass index, waist circumference, hypertension, dyslipidemia, diabetes mellitus, atrial fibrillation,and CKD attenuated this association and abolished its statistical significance.
•However, there was a statistically significant interaction in the Southern dietary pattern, with a stronger positive associationwith HF in participants younger than 65 years.
•In fully adjusted analyses, there were no statistically significant associations of incident HF with reduced or preservedejection fraction hospitalizations and the dietary patterns, nor were there any associations with the other 3 dietary patterns.
•On the basis of their findings, the investigators concluded that adherence to a plant-based dietary pattern was inverselyassociated and the Southern dietary pattern was directly associated with incident HF risk.
•To reduce HF risk, clinicians should counsel their patients to eat less meat and fried foods and more vegetables and plantproteins such as lentils, nuts, chickpeas, tofu, and beans.
•Public education regarding the potential harms of a Southern diet and potential benefits of a plant-based diet may help reverseadverse national trends in HF prevalence.
•The Mediterranean diet is high in fruit and vegetables and emphasizes healthy fats such as olive oil, nuts, avocadoes, andfish, while avoiding red meat, eggs, and fried foods.
•Mechanisms underlying the protective effect of plant-based diets against HF may include the effect of antioxidants, whichreduce reactive oxygen species, and anti-inflammatory effects.
•Reactive oxygen species, which may be increased by diets high in animal fat, may increase cardiac hypertrophy, aortic stiffness,and interstitial fibrosis, while reducing myocardial contractility.
•Plant-based diets are associated with lower serum concentrations of inflammatory biomarkers such as C-reactive protein, interleukin6, and soluble intercellular adhesion molecule-1.
•Plant-based proteins may retard CKD development and progression through beneficial effects on blood pressure, proteinuria,and glomerular filtration rate.
•Plant-based, low-sodium diets such as DASH are also associated with lower systolic and diastolic blood pressure.
•In future studies, the investigators plan to assess plant-based diets in patients starting cardiac rehabilitation, and toexamine associations of microbiome changes in plant-based diets with cardiovascular health.
•Additional research is also needed to clarify the pathophysiology underlying the association between a plant-based diet andreduction in incident HF.
•The Southern dietary pattern may be associated with increased HF risk, mediated by various factors associated with obesity,visceral adiposity, hypertension, dyslipidemia, and CKD.
•Study limitations include reliance on self-report for the food frequency questionnaire, dietary assessment only at baseline,potential residual confounding, inability to capture HF diagnosed in the outpatient setting, and study population limitedto non-Hispanic black or white participants.
•An accompanying editorial notes that the findings contribute robust evidence for dietary prevention of HF, but that furtherresearch is needed to allow precision dietary prevention, in which diet is customized to specific HF subtypes differing intheir underlying pathophysiology.
•Such research should use big data analytics and deep-phenotyping of large populations to allow more advanced disease classification.

Clinical Implications
•Adherence to a plant-based dietary pattern was inversely associated, and to a Southern dietary pattern was directly associated,with incident HF risk, based on an analysis of data from the REGARDS trial.
•To reduce HF risk, clinicians should counsel their patients to eat less meat and fried foods and more vegetables and plantproteins such as lentils, nuts, chickpeas, tofu, and beans.
•Implications for the Healthcare Team: Public education regarding the potential harms of a Southern diet and potential benefitsof a plant-based diet may help reverse adverse national trends in HF prevalence.