The pivotal role that nutrition plays in health not in doubt. At one end of the spectrum, it is common knowledge that eating a diet that is high in sugar, salt, and fat increases the risk of poorer health outcomes. At the other end, eating a balanced diet that is rich in fresh fruits and vegetables is likely to reduce the risk of certain conditions. However, drilling down to the effect of individual foods on specific conditions is notoriously difficult.
The authors of a recent review in the journal Advances In Nutrition have taken up that gauntlet. They wanted to understand how legumes, which include beans, peas, and lentils, affect heart health. In particular, they focused on cardiovascular disease (CVD) risk and CVD mortality. CVD includes coronary heart disease, myocardial infarction, and stroke. They also investigated legume consumption in relation to diabetes, hypertension, and obesity.
Study co-author Dr. Hana Kahleova, from the Physicians Committee for Responsible Medicine in Washington, DC, explains why investigating heart health is such a pressing matter, stating that
“Cardiovascular disease is the world’s leading — and most expensive — cause of death, costing the United States nearly one billion dollars a day.”
Why legumes? Legumes are rich in fiber, protein, and micronutrients but contain very little fat and sugar. Due to this, as the authors of the current study explain:
“The American Heart Association, Canadian Cardiovascular Society, and European Society for Cardiology encourage dietary patterns that emphasise intake of legumes”
to reduce levels of low-density lipoprotein (LDL, or bad) cholesterol, lower blood pressure, and manage diabetes. Recently, the European Association for the Study of Diabetes commissioned a series of systematic reviews and meta-analyses. Using the results of these studies, they hope to update current recommendations on the role of legumes in preventing and treating cardiometabolic diseases.
In the current review, the authors compared data on people with the lowest and highest intake of legumes. They found that
“dietary pulses with or without other legumes were associated with an eight per cent, 10 per cent, nine per cent, and 13 per cent decrease in CVD, coronary heart disease, hypertension, and obesity incidence, respectively.”
However, they found that there was no association between legume intake and the incidence of myocardial infarction, diabetes, or stroke. Similarly, they identified no relationship between legumes and mortality from CVD, coronary heart disease, or stroke.
Although the team identified a positive relationship between consuming higher quantities of legumes and a reduced risk of certain cardiovascular parameters, the authors’ conclusions are still relatively muted. They write:
“The overall certainty of the evidence was graded as ‘low’ for CVD incidence and ‘very low’ for all other outcomes.”