Milk is more than just a nutritious food—its structure hides components that may have significant health effects. Among these is the milk fat globule membrane (MFGM), a three-layer membrane that surrounds fat globules in milk. Scientists are only just beginning to understand the value of this tiny component in our health.
A comprehensive literature review, conducted by food scientists at the University College Cork, Ireland and Ohio State University, USA explores the potential of MFGM as a bioactive food ingredient (1). The review brings to light mechanisms underlying the bioactive effects of MFGM ingredients on human health.
What is the milk fat globule membrane?
The MFGM is a complex structure comprising a phospholipid tri-layer surrounding proteins, cholesterol, and other lipids (2). It originates during milk production in the mammary glands, enveloping fat droplets to stabilise them in the aqueous environment of milk. Studies have shown that this membrane protects the fat droplets from an early degradation in the stomach, which allows a more gradual absorption of fat (3).
This complex structure is composed of a variety of bioactive compounds, which content vary in literature in the different types of dairy foods due to the natural variability of milk composition, and laboratory techniques for isolation and purification (4):
- Polar Lipids : Phospholipids – are important for the stability of the milk fat globule, forming an emulsion to protect globules from breaking down or combining (5) and Sphingolipids – may be significant in neonatal digestion for delivery of other key components such as ceramides and sphingosine (6), mainly composed of sphingomyelin, a molecule not present in polar lipids from vegetal sources.
- Neutral lipids like sterols, mainly free cholesterol embedded in the membrane, which is known to be essential for membrane integrity, permeability, rigidity, and functionality. (7)
- Proteins – found within the MFGM are diverse; some are found in the inner layer while others are contained within the outer membrane. Some of them are enzymes know as forming a complex that influence the structure and stability of MFGM (8), while individual proteins have significant functions in digestion (9)
- Glycolipids – such as gangliosides or glycosphingolipids. First ones are known for their role in brain development and function, and particularly formation of neural connections, and the second one contributing to cell recognition, integrity of cell membranes among other roles.
The components of MFGM have several health benefits
The components of MFGM – particularly its phospholipids and proteins – have shown bioactive properties in various studies, including clinical trials. These bioactive effects range from supporting brain development to enhancing gut health and immunity.
- Gut health: MFGM sphingolipids have demonstrated anti-inflammatory effects in the intestine through a reduction in inflammatory markers. MFGM may therefore help reduce gut permeability and maintain homeostasis (10)
- Gut microbiome: Specific components of the MFGM can help promote the growth of probiotic bacteria such as Bifidobacterium and Lactobacillus rhamnosus during digestion (10)
- Immunity: Several biologically active components of the MFGM have immunomodulatory properties and may play a role in reducing bacterial or viral infection by binding to pathogens (11)
- Brain health: Sphingolipids in MFGM are associated with structural and cognitive development of the brain in infants and can also improve cognitive impairment due to stress and age through reductions in neural apoptosis and promotion of neurogenesis – needed for healthy development and maintenance of the brain (12)
- Postprandial lipemia: science is currently trying to elucidate the MFGM modulatory role on postprandial lipemia. This is particularly important because postprandial hyperlipemia is recognized as an independent risk factor for metabolic and cardiovascular diseases.
Applications and challenges of MFGM in nutrition
Use of MFGM in nutritional products has received great attention in recent years. The two main sources of MFGM are cream and whey found in milk, yogurt, fresh cheese or as byproduct of cheese manufacturing. Several commercially available MFGM-enriched ingredients are available, such as buttermilk powder and whey protein concentrate. Manufacturers are also adding MFGM to infant nutrition formulas with the aim of supporting immune function and cognitive development.
Meanwhile, researchers are still unravelling how differences in the composition of the MFGM affect its bioactive potential. In addition, structural changes that occur during dairy processing may affect the properties of the MFGM.
- Variability in composition: The composition of MFGM can vary based on factors such as the source of dairy product, leading to differences in its biological properties
- Processing effects: Dairy processing such as homogenisation, pasteurisation, sterilisation, heat treatment may impact the structure of MFGM, breaking it into fragments and potentially affecting its bioactive potential
The future of MFGM research
The researchers conclude that we still to further understand the effects of food processing, source and composition on the biological functioning of the MFGM. They recommend further studies of interactions between the MFGM and other components in various dairy food matrixes such as yogurt, infant formula, or milk. As we learn more, MFGM holds the potential to unlock new ways to promote health, from infancy to adulthood.
“The MFGM is a unique complex with many components that have demonstrated effects on brain, gut, and immune health and development.”