Did you know that February is American Heart Month? Beans and other pulses are often recommended as part of a healthy diet that can reduce the risk of heart disease. To honor American Heart Month, I want to share about one of my favorite recent studies about beans and heart health.
I recently did a write-up about this study in the January 2024 e-newsletter for Northarvest Bean Growers Association. I am expanding upon that a bit here:
Research on Beans and Heart Health
Many health benefits are attributed to regularly eating beans, including reducing the risk of cardiovascular disease (aka heart disease). A recent study by Dr. Katarina Doma and colleagues did an excellent job of evaluating potential benefits of beans for heart health. You can find the full article, Canned Beans Decrease Serum Total and LDL Cholesterol in Adults with Elevated LDL Cholesterol in a 4-wk Multicenter, Randomized, Crossover Study in the Journal of Nutrition, linked to online here. Below, you can see a screenshot of the study title, authors, and abstract. This study had a couple unique approaches that I think make it extra interesting – read on to see what those were!
What did the researchers do?
The research team worked with a group of adults who had elevated LDL cholesterol (often called “bad” cholesterol), to see if eating beans could help lower cholesterol levels. The study delved into how the daily amount eaten and different bean types may affect this. The researchers had study participants eat a daily rotation of five different types of beans: black, navy, pinto, dark red kidney, and white kidney. Participants completed three 4-week treatments, wherein they ate one of the following for every day of the treatment: 1/2 cup of cooked beans, 1 cup of cooked beans, or white rice as the control.
So, what was unique about their study approach, you ask?
- The researchers had study participants consume a rotation of beans. Instead of just consuming one or maybe two types of beans, as is the case in many studies, participants ate a wider variety of beans (i.e., black, navy, pinto, dark red kidney, and white kidney beans).
- The researchers examined different bean consumption levels. One of the current challenges in bean research is answering the question: what is the right serving size to optimize health benefits? Of course, this may vary among individuals. But, we can still gather information to at least give us an idea. For example, although having one bite of beans a day is better than no beans, it is not likely that with only one bite we can reap maximum health benefits. So, the researchers looked at consumption levels of both 1/2 cup and 1 cup cooked beans per day.
What were the study results: do beans benefit heart health?
The researchers found that eating beans decreased both total cholesterol and LDL cholesterol. Interestingly, when they examined statistical significance, they found that only when participants ate 1 cup of beans was the reduction in cholesterol significant, when compared to the white rice control. This suggests that the amount of beans eaten is important, and daily consumption of 1 cup of beans may be better than 1/2 cup in terms of cholesterol reduction. High cholesterol is a risk factor for heart disease. Thus, regularly eating beans at this higher level may help reduce cholesterol levels and therefore lower the risk for heart disease.
Below, I added the orange circle to Figure 2, to help highlight these results. You can see that after 4 weeks of consuming 1 cup of cooked beans each day, both total and LDL cholesterol levels were significantly lower when compared to the control of white rice. Levels of total and LDL cholesterol were lower after daily consumption of 1/2 cup of beans for 4 weeks as well, but the results were not statistically significant when compared to the control.
Another conclusion the authors reached was that, when their study results were taken together with those of previous studies, consumption of both a single bean type or of multiple types of beans can help decrease total and LDL cholesterol.
Why might beans help lower cholesterol?
There are several reasons that beans may show these cholesterol-lowering effects. One is the high dietary fiber content of beans. It is a fact: beans are one of the best natural sources of dietary fiber. Fiber has numerous beneficial outcomes, such as reducing the body’s absorption of cholesterol. Another potential reason is that beans can help increase satiety (i.e., the feeling of being full) – likely due to their high fiber and protein content. This could result in people altering their food intake and choices, which could also help reduce the risk for heart disease.
Bean Consumption Can Lower Cholesterol
In the abstract of their article, the authors make an important conclusion: regularly eating 1 cup of cooked beans may be a great way to lower cholesterol, thereby helping prevent cardiovascular disease and supporting heart health. Basically, beans and heart health go hand-in-hand! You can see the highlights I added directly to the authors’ wording, below:
Looking for some bean recipe inspiration? I’ve got you covered!