A study conducted at the University of Helsinki indicates that even a partial substitution of animal protein with plant protein improves the fatty acid composition of the diet and increases fibre intake.
In the study, 136 adult Finns followed one of three predetermined diets for 12 weeks. One of them corresponded with that of average Finns, comprising roughly 70% animal-derived protein and 30% plant-based protein, with most of the latter originating from cereal products. In the second diet, half of the protein was derived from plant products and the other half from animal products, while the third one comprised 30% animal protein and 70% plant-based protein.
Red and white meat as well as dairy products were substituted by adding legumes in various forms to the diets. Additionally, the subjects consumed nuts, seeds and cereal products. All of the diets included the same amount of fish and eggs.
Increasing the plant protein ratio may promote cardiac health
Less saturated and more polyunsaturated fatty acids were obtained from the diets where animal protein had been substituted with plant protein compared to the control diet, which represented the average Finnish diet.
The likeliest explanation for this is that the consumption of animal protein sources containing saturated fat decreased, in addition to which a great deal of polyunsaturated fatty acids were introduced into the diet through nuts and seeds in particular.
“Comparing the diet heavy on animal protein to the one richest in plant-based protein, we observed a change in the quality of fat so substantial that it significantly lowered both the total cholesterol and LDL-cholesterol levels. In other words, substituting plant protein sources for animal protein sources can play a part in promoting cardiovascular health,” says Anne-Maria Pajari from the Department of Food and Nutrition of the Faculty of Agriculture and Forestry, University of Helsinki, who headed the project.
In comparison with the animal protein-rich study diet, the two other diets also provided more fibre, even though the average fibre intake of the study subjects was already in line with Finnish dietary recommendations to begin with. This indicates that plant protein sources are also good sources of fibre. Research has shown that ample fibre intake reduces the risk of colorectal cancer, making it possible that replacing animal protein with plant protein also promotes gut health.
According to the study subjects, particularly the diet based equally on plant and animal protein was easy to adhere to.
“Such a diet is already quite well implemented by eating vegetarian food as one of the principal meals of the day, while the other can have, for example, red meat, fish or poultry. Since this kind of diet already had a positive effect on fat quality and fibre intake, it could be more widely recommended to Finnish adults,” Pajari states.
The unifying vision of the multidisciplinary ScenoProt – Novel Protein Sources for Food Security and Climate project is that, in 2030, Finns will be eating healthy and sustainably produced food. The project is funded by the Strategic Research Council of the Academy of Finland.
Essi Päivärinta, Suvi T. Itkonen, Tiina Pellinen, Mikko Lehtovirta, Maijaliisa Erkkola, Anne-Maria Pajari. Replacing Animal-Based Proteins with Plant-Based Proteins Changes the Composition of a Whole Nordic Diet—A Randomised Clinical Trial in Healthy Finnish Adults. Nutrients 2020, 12(4), 943; https://doi.org/10.3390/nu12040943