A Chilean study compares yoghurt and whey protein
Researchers from the Universidad Mayor, the University of Chile, Universidad Andrés Bello and the University of O’Higgins examined how yoghurt and whey protein performed when included in a strength-training programme for older adults. The study was published in Scientific Reports.
Participants were sedentary older people who completed eight weeks of resistance exercise. During the intervention, their daily protein intake ranged from 1.5 to 1.7 grams per kilogram of body weight. One group incorporated yoghurt, while the other used whey protein.
The two groups recorded comparable increases in muscle mass. They also improved measures of arm and leg strength, muscular power and walking speed. The findings therefore describe similar muscle and physical-performance results for the two protein strategies under the conditions of the study.
The clearest difference appeared in the intestinal microbiota. Yoghurt consumption was associated with changes in bacterial communities, including an increase in the genus Coprococcus. This group of bacteria is linked to the production of butyrate, a short-chain fatty acid involved in the functioning of the intestinal ecosystem.
Paulina Calderón-Romero, a researcher at Universidad Mayor who participated in the study, said the findings draw attention not only to the quantity and quality of protein but also to the food matrix in which it is consumed. Two foods can provide protein and produce similar muscular responses while being associated with different changes in the microbiota.
The researchers did not conclude that yoghurt can replace whey protein in every circumstance. Powdered protein may be useful when someone cannot meet daily requirements through food. Calderón-Romero said that, when a varied diet adequately covers protein needs, supplements are not necessarily indispensable; supplementation for older people should be assessed individually and, where appropriate, with professional guidance.
The study also identified strength training as a central part of the intervention. Because all participants exercised, the improvements in muscle mass, strength, power and walking ability cannot be attributed solely to yoghurt or whey protein. The research examined nutrition as one component of a broader approach to maintaining muscle during ageing, a period when declining muscle mass and strength can contribute to sarcopenia, falls and functional limitations.
The findings add to research on dairy products that combine protein with fermentation. The authors’ comparison focused on whether the food matrix might be associated with effects beyond the basic amount of protein, particularly in relation to the gut microbiota. The study did not establish that yoghurt was universally superior to whey protein.
