Goat milk boosts muscle health better than cow’s milk in animal study

Researchers show that specific dairy products, particularly fortified goat milk, offer superior benefits in combating muscle wasting and inflammation in aging mice, pointing to new dietary strategies for healthier aging.

Study: Four Dairy Products Mitigates Sarcopenia in Mice by Modulating Muscle Inflammation, Autophagy, and Protein Degradation. Image Credit: StockMediaSeller / Shutterstock

In a recent study published in the Food Science & Nutrition journal, researchers used murine models to investigate whether four everyday dairy products, specifically variants of goat and bovine milk, could delay the progression of sarcopenia—the age-related loss of muscle mass, strength, and function.

Study findings reveal that mice fed dairy-enriched diets exhibited reduced markers of muscle inflammation and improved muscle fiber integrity. This suggests that daily consumption of dairy products may support muscle health by modulating inflammatory and immune pathways. However, the effects vary significantly depending on the type and composition of dairy products.

Background

Sarcopenia is a stealthy yet debilitating consequence of aging, clinically characterized as the progressive loss of strength, muscle mass, and function leading to frailty, falls, and increased healthcare costs. The condition is emerging as a severe public health concern in today’s rapidly aging population, with 10–27% of the global population estimated to live with the disease.

Current prevention strategies include supervised resistance exercises and high-protein diets to slow the progression of the condition. Dairy products, in particular, are gaining considerable attention, with the Asian Working Group for Sarcopenia recommending their consumption to sarcopenia patients.

Unfortunately, these recommendations are based exclusively on dairy’s reputation as a source of high-quality protein and its observed benefits in general age-associated health outcomes, primarily due to its vitamin D and calcium content. The direct benefits of dairy on muscle mass and function, as well as the mechanisms by which its products promote healthy muscle metabolism, remain unverified.

About the study

A handful of recent studies suggest that fermented dairy products contain bioactive peptides with anti-inflammatory and antioxidant properties. To simultaneously elucidate the role of dairy products in sarcopenia outcomes and investigate the mechanisms of their action, the present study leverages animal (aging mice) model systems to explore the impacts of consuming four specific dairy products on muscle integrity, inflammation, mitochondrial function, and relative muscle-degradation-associated gene expression.

The model system consisted of SPF C57BL/6 mice (n = 60, sex = male, age = 8 months) randomly assigned to six experimental groups (each n = 10): 1. NC (normal control), 2. SOP (sarcopenia control), 3. GWM (goat whole milk), 4. GLM (goat low-fat milk), 5. GFM (goat fortified vitamin D and calcium low-fat milk), and 6. BWM (bovine whole milk). The NC group was administered 5 mg/kg saline intraperitoneally for 8 weeks. All other groups were administered dexamethasone for the same duration as a means of artificially inducing sarcopenia.

Outcomes of interest included grip strength (measured using a grip strength meter), weight (fat and lean), bone mineral density (dual-energy X-ray absorption [DXA]), autophagy (western blotting), muscle morphology, host metabolism (XploreMet platform), inflammation, and gut microbial health (16S rRNA gene amplicon sequencing).

Statistical analyses included confirmations of sample homogeneity and normality, analysis of variance (ANOVA) for reporting multigroup comparisons, least significant difference (LSD) test for reporting pairwise comparisons, and linear discriminant analysis effect size (LEfSe) analysis for gut microbiotal evaluations. Gut microbiota function was predicted using the KEGG and PICRUSt2 pathway libraries. The outcomes of metabolomic assays were elucidated using univariate analyses and orthogonal partial least squares discriminant analysis (OPLS-DA).

Study findings

At study initiation (baseline), all sarcopenia (non-NC group) mice demonstrated reduced grip strength and lean weight. Dairy supplementation alleviated the latter concern (all dairy products caused a surge in lean weight) but did not significantly address the former. Critically, only goat milk products (not bovine) significantly reduced fat weight.

Molecular investigations revealed that all dairy products impacted sarcopenia through similar mechanisms: activation of the PI3K/Akt/mTOR pathway, with low-fat goat milk (GLM/GFM) showing stronger mTOR activation; enhancement of muscle regeneration; reduced AMPK phosphorylation; and upregulated MyoG expression, specifically in GFM-supplemented mice (fortified goat low-fat milk). GFM-supplemented mice notably demonstrated the highest MyoG expression levels of the dairy products tested. Only GFM restored both MyoD1 and MyoG expression, while the others restored only MyoD1.

Autophagy investigations presented a similar picture, with all dairy products promoting autophagy through increased LC3B expression and decreased p62 levels. However, low-fat goat milk (GLM) showed the most substantial reduction in p62 levels. Dairy products were also observed to benefit inflammation marker profiles, with significant reductions in CRP, IL-1β, IL-6, TNF-α, and CXCL10 levels compared to SOP controls.

Gut microbial investigations revealed that all dairy products promoted the growth of beneficial bacteria, especially those from the genus Leuconostoc. Goat’s milk (but not bovine milk) further enriched Acinetobacter and Lactococcus populations. Most importantly, mice supplemented with GLM and GFM showed increased densities of S. sciuri. S. sciuri may contribute to muscle health benefits, suggesting low-fat goat’s milk variants as promising candidates in non-invasive sarcopenia interventions. A novel “dairy-microbial score” revealed that GLM and GFM had significantly higher beneficial microbial profiles compared to whole goat milk, correlating with lower fat mass. Metabolomics revealed leucine enrichment in the GFM groups, which was negatively associated with the dairy-microbial score.

Bone mineral density improved with GWM, GFM, and BWM, but not GLM, underscoring composition-dependent effects.

Conclusions

This study presents promising evidence that regular consumption of dairy products, particularly low-fat goat milk fortified with vitamin D and calcium (GFM), could help delay or prevent sarcopenia by reducing inflammation and supporting muscle regeneration. While findings are currently limited to animal models, they underscore the importance of dairy composition (source, fat content, fortification) and frequent consumption in shaping long-term muscle health.