Consuming more legumes and less red and processed meat may have a surprisingly positive impact on men’s health

(Press-News.org) A University of Helsinki study found that partially replacing red and processed meat with pea- and faba bean–based foods resulted in reduced total and ‘bad’ LDL cholesterol levels in men, along with weight loss.

On average, men consume significantly more red and processed meat than is recommended, and more than women do. The high nutritional value of legumes makes them well suited to replacing meat. However, they do not naturally contain vitamin B12, which is found in animal-derived foods. The BeanMan study investigated how partially replacing red and processed meat with legumes thriving in Finnish conditions affected men’s health and levels of critical micronutrients in the blood.

In the study, 102 working-age men were divided into two groups. For six weeks, one group ate 760 grams of red and processed meat a week, that is, the average amount consumed by Finnish men. This accounted for one-quarter of total protein intake. 

Throughout the study, the other group’s diet included a substantial proportion of foods based on peas and faba beans, constituting 20% of total protein intake. In addition, the group members ate 200 grams of red and processed meat per week, comprising 5% of total protein intake. This corresponds to the recommended upper limit for red meat consumption in the planetary health diet. 

While the participants otherwise continued to follow their own diet, they consumed no red or processed meat or legumes other than the foods supplied as part of the study. Red meat encompassed beef and pork, while processed meat comprised sausages and cold cuts made from the same. 

The men who ate a large amount of pea- and faba bean–based foods alongside meat during the study lost an average of one kilo in weight, whereas those who ate only meat dropped just 300 grams.  The results indicate that eating more legumes and less red and processed meat reduces total and LDL cholesterol levels andthe risk of cardiovascular disease and type 2 diabetes, and may support weight management.

The positive change in blood cholesterol levels was expected for the legume group due to the enhanced quality of fat consumed. However, the researchers were surprised by the weight loss. 

“In a trial setting, participants often monitor their eating more closely, which may contribute to weight loss. But in this study, despite its relatively short duration, the legume group lost significantly more weight than the meat group. We didn’t encourage the participants to lose weight, but asked them to continue eating as before, apart from consuming the foods we provided,” says Professor of Molecular Nutrition Anne-Maria Pajari of the Faculty of Agriculture and Forestry.

Partially replacing meat does not jeopardise critical nutrient intake While cutting back on red meat reduced vitamin B12 intake in the legume group, the status of this vitamin remained at a safe level by the end of the study. Moreover, dietary iron intake was higher for the legume group, whereas no difference was observed between the groups in iodine intake. 

“In the short term, critical nutrient intake wasn’t jeopardised in the legume group. This was likely because the participants remained on mixed diets, rather than cutting out any foods entirely. However, research is needed on the effects of switching to plant-based diets on the body’s nutritional status, particularly in vulnerable population groups, such as children and older adults,” states Pajari. 

She notes that the legume group participants followed their diet successfully even though it included more legumes and less red meat than typically recommended. 

“The legume food products we provided were quick to cook, making them easy to use. We also handed out recipes to encourage cooking. Based on our findings, I believe a moderate dietary change towards a more sustainable direction, using peas, beans and lentils, is possible for most of us,” she says, delighted.

The BeanMan study was conducted as part of the soon-to-conclude, multidisciplinary Leg4Life (Legumes for Sustainable Food System and Healthy Life) project, funded by the Research Council of Finland’s Strategic Research Council. The study’s previously reported findings demonstrated that eating more legumes and less red and processed meat is safe for both bone health and amino acid intake. Results on intestinal health will be published later.

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