Early Data Suggest Plant-Based Foods Could Improve Outcomes in HF

Increasing dietary intake of plant-based omega-3 fatty acids, found in foods like walnuts and canola oil, may be a key to decreasing risks of hospitalization and death in patients with heart failure, a new study suggests.

Much research has been devoted to associations between the marine-derived omega-3s like eicosapentaenoic acid (EPA), found in fatty fish or prescription supplements, as a secondary prevention measure in HF, including for prevention of recurrent HF hospitalization. However, less is known about the benefits of plant-derived omega-3s, primarily alpha-linolenic acid (ALA).

“We knew from our previous research that levels of ALA at the time of having a heart attack were related to prognosis,” study co-author Aleix Sala-Vila, PharmD, PhD (Hospital del Mar Medical Research Institute, Barcelona, Spain), told TCTMD. “So, we decided to just go for it and try to find any kind of association between these ALAs and prognosis in patients with heart failure.”

Any one of us can improve our diet at any time, and [doing so] will translate to a healthy aging. Aleix Sala-Vila

While most dietary studies use participant recall or food diaries, Sala-Vila and colleagues, led by Iolanda Lázaro, PhD (Hospital del Mar Medical Research Institute), used blood samples as an indicator of dietary intake of ALA to group patients into quartiles and then followed them for 2.4 years. What they found was that compared with patients in the lowest quartile, those in the three other quartiles of ALA levels had a 39% reduction in the composite endpoint of all-cause mortality/first HF hospitalization.

The investigators believe this causal effect suggests that higher intake of plant-based foods, or even better absorption of them, might be a target for improving CV health and could ultimately translate into better HF outcomes.

“The important thing is that there is no evidence that including this type of food in your overall diet is going to be harmful for you at all,” Sala-Vila said. “Any one of us can improve our diet at any time, and [doing so] will translate to a healthy aging.”

In an accompanying editorial, Abdallah Al-Mohammad, MD (University of Sheffield, United Kingdom), says that while the findings are hypothesis-generating, the authors’ “proposal of a potential role for this source of nutrition in improving the morbidity and mortality rates of patients with HF cannot yet be substantiated.”

Al-Mohammad adds that the study provides impetus “to test whether increased intake of ALA could potentially raise the level of ALA in the serum sufficiently to move a patient to a quartile associated with a better risk profile,” and if doing so translates to better HF outcomes.

Focusing on Those With Lowest Levels

For the study, published October 24, 2022, in the Journal of the American College of Cardiology, Lázaro and colleagues included 905 ambulatory patients (mean age 67 years; 31.7% female) with HF of varied etiologies. Patients were equally represented across the four quartiles of serum ALA.

In addition to the reduction seen in the primary composite endpoint, patients in quartiles 2, 3, and 4 had  lower rates of all-cause death (P = 0.002), CV death (P = 0.004), first HF hospitalization (P = 0.003), and the composite of CV death and HF hospitalization (P = 0.001) compared with those in the lowest quartile. When comparing between quartiles 2 through 4, however, no differences in any clinical endpoints were seen.

Lázaro and colleagues also point out that in addition to being safe, foods rich in ALA are also fairly low in cost, which could translate to the greatest benefits being seen in disadvantaged populations with low serum levels.

According to Al-Mohammad, enrolling HF patients with low ALA levels is most likely where the next step in this research should begin, in order to clarify that low levels are a marker of enhanced risk. Sala-Vila said he agrees.

“Then we need to define how many patients do we want to screen, what type of food are we going to give to them, and the length of dose of the food that we are going to test,” Sala-Vila added. But he noted the possibility that the benefits of circulating ALA might differ due to genetics or microbiota, which will also be a key determinant of the final effect of any kind of intervention to increase dietary ALA.