Oct. 25, 2022 -- Including more foods rich in an omega-3 called alpha-linolenic acid (ALA) could help people with heart failure, a new study suggests.
ALA is an omega-3 fatty acid found mainly in plants. Higher blood levels of ALA were tied to fewer deaths and fewer first trips to the hospital for heart failure compared to lower levels in the study, published in the Journal of the American College of Cardiology. Some of the best sources of plant-based omega-3s include flax, which can be purchased as seeds or oil and is often found in cereals, baked goods, and other products. Chia seeds, pumpkin seeds, walnuts, soy foods, canola oil, seaweed, edamame, and kidney beans are also good sources.
"The most striking finding to us is the clear difference between patients in the bottom 25% -- the lowest ALA levels -- compared to the other 75%," says Aleix Sala-Vila, PHD, of the Hospital del Mar Medical Research Institute in Barcelona, Spain.
The researchers studied blood samples from 905 heart failure patients. The average age was 67, and about a third were women. After a follow-up of about 2 years, 140 people died of any cause, 85 died from cardiovascular disease, and 141 people were hospitalized for the first time with heart failure.
Patients with higher blood levels of ALA were significantly less likely to die or have a first heart failure hospitalization than those with lower levels, according to the analysis.
More research is needed to show definitively whether increasing dietary ALA can improve heart failure outcomes, Sala-Vila says. But for now, "including some ALA-rich foods such as walnuts in the diet might translate into cardiovascular benefits for anyone, whether they have heart failure or not. There is no evidence of any harmful effect of one daily serving of walnuts, not even on weight gain."
Diet Often "Overlooked"
JoAnn E. Manson, MD, DrPH, chief of the Division of Preventive Medicine at Brigham and Women's Hospital in Boston, called the study findings "promising."
"Diet is often overlooked as an important factor in maintaining good health and good heart health," she says. "This study gives further support that a dietary factor may influence heart health, including heart failure. Until recently, most of the dietary emphasis has been on salt intake, which is very important, but not as much as some of these other dietary factors."
However, the study doesn't prove that increasing ALA blood levels will definitely improve heart failure prognosis, she says.
"It may be that the foods that are leading to this higher blood level of ALA make up the type of plant-based diet that's been linked to a lower risk of cardiovascular disease, such as the Mediterranean diet. The findings also could be the result of other factors that aren't fully controlled for in the analysis, or the study participants may be more compliant with their medications."
Nevertheless, she says, "It's reasonable to recommend that people with a history of heart failure or who are at high risk increase their intake of ALA-enriched foods."
It's also good advice for everyone to follow a heart-healthy diet, including plenty of ALA, she adds.
"Have a large salad or a couple of smaller salads every day, add canola or flaxseed oil, and sprinkle on some walnuts," she advises. "This will give you a high intake of ALA every day."